Conservation 

Effects 

Assessment 

Project 

March 2022

Conservation Practices on 

Cultivated Cropland 

A Comparison of CEAP I and CEAP II 

Survey Data and Modeling 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating 

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Cover Photo: Lynn Betts, NRCS. Conservation tillage system that leaves at least 30 percent of the soil 

covered after planting with last year's crop residue. North-central Iowa. Residue adequately controls 

erosion by both wind and water on this soil type. Photo ID NRCS IA99102 
 

 

 

 

CEAP National Report: 

Conservation Practices on Cultivated 

Cropland 

EXECUTIVE SUMMARY 

The U.S. Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS) 

evaluates conservation trends and effects on cultivated cropland through the multiagency 

Conservation Effects Assessment Project (CEAP), a sampling and modeling approach using 

natural resource data and farmer surveys. The first set of farmer surveys was conducted in 2003–

06 (CEAP I) with reports released from 2010 through 2014. Now, comparison data from farmer 

surveys conducted in 2013–16 (CEAP II) make it possible to estimate conservation adoption and 

effects between the CEAP survey periods. 

The agricultural landscape is dynamic, shaped by policy, technology, and natural resource 

drivers among others, which together affect farmer decisions and conservation trends. Between 

the CEAP surveys, increased demand and higher prices for commodities encouraged production 

expansion in nearly all regions of the country. A warming climate, longer growing season, and 

advances in seed technology and higher yielding crop varieties drove cropping pattern shifts, 

most notably in the northern and southern plains, where corn and soybean production replaced 

wheat and other close-grown crops with lower average nutrient needs, and fallow periods. 

The agricultural landscape continued to shift between the two survey periods. Demand for 

commodities increased, particularly corn and soybeans, and higher prices encouraged production 

expansion. A warming climate, longer growing season, and seed technology advances extended 

the northern boundaries of corn and soybean production, where they replaced crops such as 

wheat and other close-grown crops with significantly lower average nutrient needs and fallow 

periods. 

During the decade: 

● Farmers increasingly adopted advanced technology, including enhanced-efficiency fertilizers and 

variable-rate fertilization to improve efficiency and benefit rural economies and the environment. 

● More efficient conservation tillage systems, particularly no-till, became the dominant form of 

tillage, reducing erosion and fuel use. 

● Use of structural practices increased, largely in combination with conservation tillage as farmers 

integrated multiple conservation treatments to gain efficiencies. 

● Conservation crop rotation and cover crop use increased, as did the use of high-biomass crops in 

rotation. 

● Irrigators shifted toward more efficient pressure-based systems, and improved water management 

strategies decreased per-acre water application rates. 
 

 

 

 

 

 

 

 

 

 

 

ii Conservation Effects Assessment Project 

As a result, CEAP estimates: 

● Average annual water (sheet and rill) and wind erosion dropped by 70 million and 94 million 

tons, respectively, and edge-of-field sediment loss declined by 74 million tons. 

● Nearly 26 million additional acres of cultivated cropland were gaining soil carbon, and by CEAP 

II carbon gains on all cultivated cropland increased by over 8.8 million tons per year. 

● Nitrogen and phosphorus losses through surface pathways declined by 3 and 6 percent, 

respectively. However, subsurface nitrogen and soluble phosphorus losses increased by 13 and 11 

percent, respectively. 

● Per-acre irrigation application rates dropped by 19 percent and national withdrawals by 7 millionacre-feet. 

● Average annual fuel use dropped by 110 million gallons of diesel fuel equivalents, avoiding 

associated greenhouse gas emissions of nearly 1.2 million tons of carbon dioxide equivalents. 

While gains were made, shifts in crops, cropping patterns, and tillage systems outpaced nutrient 

application research and guidance and industry capacity to deliver and apply nutrients efficiently. 

Consequently, subsurface losses of nitrogen and soluble phosphorus increased with the 

expansion of crops with higher nutrient demand and conservation tillage systems, which promote 

water infiltration and subsurface flow. Transitioning to conservation tillage systems, particularly 

no-till, requires nutrient method and form adjustments to incorporate nutrients that previously 

may have been tilled into the soil under conventional systems. 

Recognizing the variability in conservation treatment needs within fields and addressing soil 

health and nutrient management as a system is critical to achieving the full benefits of advanced 

technology, tillage efficiency, and conservation measures. For example, in each CEAP survey 

period, a small proportion of acres accounted for most nutrient and sediment losses; in CEAP II, 

73 percent of the subsurface nitrogen losses came from 28 percent of the acres, generally 

smaller, vulnerable areas within larger fields. 

A systems approach to conservation recognizes in-field variability and the connectivity of natural 

resources, and that conservation measures designed to benefit one resource also may affect 

another, potentially negatively. For example, in a watershed in which soluble phosphorus is a 

resource concern, nutrient incorporation may be needed to reduce potential soluble losses, but it 

also may reduce the maximum soil carbon benefits of strict no-till. Conservation planning 

assesses the agri-environmental system to identify and develop workable solutions that fit the 

operation, the land, and the resource need in balance with local natural resource priorities. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland iii 

TABLE OF CONTENTS 

EXECUTIVE SUMMARY ..........................................................................................................................................i 

INTRODUCTION....................................................................................................................................................1 

CEAP Production Regions .................................................................................................................................................. 1 

A Changing Agricultural Landscape ................................................................................................................................... 5 

Farms and Ownership .................................................................................................................................................. 5 

Cropping Patterns......................................................................................................................................................... 6 

Prevailing Weather....................................................................................................................................................... 6 

Production Technology ................................................................................................................................................ 7 

HOW DID THE USE OF CONSERVATION PRACTICES CHANGE BETWEEN THE CEAP SURVEYS? .............................. 10 

Structural Practices and Conservation Tillage ................................................................................................................. 10 

Structural Practices plus Conservation Tillage ........................................................................................................... 10 

Structural Practices .................................................................................................................................................... 11 

Conservation Tillage ................................................................................................................................................... 14 

Structural Practices and Conservation Tillage on Vulnerable Cropland.....................................................................17 

Cultivated Cropland with No Structural Practices or Conservation Tillage ................................................................ 21 

Conservation Crop Rotations and Cover Crops ............................................................................................................... 22 

Conservation Crop Rotations .....................................................................................................................................22 

Cover Crops ................................................................................................................................................................ 25 

Irrigation.......................................................................................................................................................................... 27 

Water Sources............................................................................................................................................................ 29 

Application Methods.................................................................................................................................................. 30 

Application Efficiency ................................................................................................................................................. 33 

Application Amount ................................................................................................................................................... 34 

Nutrient Management..................................................................................................................................................... 35 

Rate ............................................................................................................................................................................ 37 

Method....................................................................................................................................................................... 37 

Timing......................................................................................................................................................................... 39 

Manure Application Trends............................................................................................................................................. 41 

HOW DID CONSERVATION ADOPTION AFFECT RESOURCE CONCERNS? .............................................................. 46 

Erosion............................................................................................................................................................................. 46 

Sheet and Rill Erosion................................................................................................................................................. 47 

Wind Erosion .............................................................................................................................................................. 49 

Sediment.......................................................................................................................................................................... 53 

Surface Nitrogen.............................................................................................................................................................. 56 

Sediment-Transported Phosphorus................................................................................................................................. 59 

Subsurface Nitrogen ........................................................................................................................................................ 62 

Soluble Phosphorus......................................................................................................................................................... 64 

Soil Carbon....................................................................................................................................................................... 67 

Resource Concerns Summary .......................................................................................................................................... 71 

HOW DID SEDIMENT AND NUTRIENT MANAGEMENT CHANGE?......................................................................... 73 

Sediment.......................................................................................................................................................................... 73 

Sediment Management by Tillage System ................................................................................................................. 74 

Sediment Management on Vulnerable Acres ............................................................................................................ 77 

Nitrogen........................................................................................................................................................................... 78 

Nitrogen Management by Tillage System .................................................................................................................. 79 

Nitrogen Management on Vulnerable Acres..............................................................................................................82 

Phosphorus......................................................................................................................................................................83 

Phosphorus Management by Tillage System ............................................................................................................. 84 

Phosphorus Management on Vulnerable Acres......................................................................................................... 87 

HOW DID THE CONSERVATION CONDITION IN THE CEAP SURVEYS COMPARE TO ALTERNATIVE TREATMENT 

LEVELS?..............................................................................................................................................................89 

Erosion Control and Nutrient Management (ENM)......................................................................................................... 89 

Comparing Change in Cultivated Cropland Conservation Treatment Levels in CEAP Surveys ........................................ 91 

Erosion Control and Nutrient Management Treatment (ENM) Effects by Treatment Need........................................... 92 

How Did Conservation in CEAP I and CEAP II Compare to ENM? .................................................................................... 94 

Erosion and Sediment ................................................................................................................................................ 95 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

iv Conservation Effects Assessment Project 

Nitrogen .....................................................................................................................................................................97 

Phosphorus................................................................................................................................................................. 98 

Soil Carbon ................................................................................................................................................................. 99 

Summary ..................................................................................................................................................................100 

SUMMARY AND AGENCY ACTIONS................................................................................................................... 101 

APPENDIX 1. OVERVIEW OF THE CEAP SAMPLING AND MODELING APPROACH ............................................... 103 

APPENDIX 2. REGIONAL TABLES ....................................................................................................................... 106 

APPENDIX 3. MANAGEMENT LEVELS CRITERIA ................................................................................................. 163 

Tables 

Table 1. Structural Practices, Conservation Tillage, and Both on Cultivated Cropland, CEAP I and CEAP II ....................................10 

Table 2. Structural Practice Adoption, CEAP I and CEAP II............................................................................................................... 13 

Table 3. Tillage Groups and Classes, CEAP I and CEAP II ................................................................................................................. 14 

Table 4. Highly Erodible Cropland by Treatment Group, CEAP I and CEAP II................................................................................... 18 

Table 5. Cultivated Cropland with High and Moderately High Runoff (SVI) Ratings by Treatment Group, CEAP I and CEAP II....... 20 

Table 6. Cultivated Cropland with No Structural Practices or Conservation Tillage, CEAP I and CEAP II ........................................ 21 

Table 7. Cultivated Cropland by Crop Rotation Group, CEAP II........................................................................................................ 23 

Table 8. Cultivated Cropland by Crop Rotation Group and Tillage Group, CEAP II .......................................................................... 24 

Table 9. Use of Cover Crops in Major Crop Rotation Groups, CEAP II.............................................................................................. 25 

Table 10. Cover Crops and Conservation Crop Rotations by Major Crop Rotation Group, CEAP II .................................................. 26 

Table 11. Cover Crop Use by Region, CEAP II................................................................................................................................... 26 

Table 12. Total Cropland, Irrigated Cropland, and Change in Irrigated Acres, CEAP I and CEAP II, Nationally and by Region........ 27 

Table 13. Irrigation Water Applications, Total Water Applied, and Change in Water Applications, CEAP I to CEAP II, by Region.. 35 

Table 14. Nutrients Applied on Cultivated Cropland, CEAP I and CEAP II ........................................................................................ 37 

Table 15. Cultivated Cropland with Nutrients Applied by Type and Incorporation, CEAP I and CEAP II .......................................... 39 

Table 16. Average Annual Nutrient Application Rates—Manured and Commercial Only............................................................... 42 

Table 17. Cultivated Cropland with Manure Applied, by Source, CEAP I and CEAP II ......................................................................45 

Table 18. Sheet and Rill Erosion by Threshold, CEAP I and CEAP II .................................................................................................. 47 

Table 19. Cultivated Cropland with Sheet and Rill Erosion above T by Soil Vulnerability Runoff and Rainfall, CEAP II ................... 49 

Table 20. Wind Erosion by Threshold, CEAP I and CEAP II ............................................................................................................... 51 

Table 21. Cultivated Cropland with Wind Erosion above T by Soil Vulnerability Wind and Rainfall, CEAP II................................... 53 

Table 22. Sediment Loss by Threshold, CEAP I and CEAP II..............................................................................................................55 

Table 23. Cultivated Cropland Exceeding the Sediment Threshold by Soil Vulnerability Index Runoff and Rainfall, CEAP II........... 55 

Table 24. Surface Nitrogen Loss by Threshold, CEAP I and CEAP II.................................................................................................. 56 

Table 25. Cultivated Cropland Exceeding Surface Nitrogen Threshold by SVI Runoff and Rainfall, CEAP II ....................................58 

Table 26. Sediment-Transported Phosphorus Loss by Threshold, CEAP I and CEAP II .....................................................................59 

Table 27. Cultivated Cropland Exceeding Sediment-Transported Phosphorus Threshold by SVI Runoff and Rainfall, CEAP II ........ 61 

Table 28. Subsurface Nitrogen Loss by Threshold, CEAP I and CEAP II ............................................................................................ 62 

Table 29. Cultivated Cropland Exceeding Subsurface Nitrogen Threshold by SVI Leaching (SVI-L) and Rainfall, CEAP II................ 64 

Table 30. Soluble Phosphorus Loss by Threshold, CEAP I and CEAP II.............................................................................................. 65 

Table 31. Cultivated Cropland Exceeding Soluble Phosphorus Threshold by SVI Runoff and Rainfall, CEAP II ................................ 67 

Table 32. Cultivated Cropland Exceeding the Soil Carbon Threshold by SVI Runoff and Rainfall, CEAP II ....................................... 70 

Table 33. Nitrogen and Phosphorus Loss by Carbon Trend and Nutrient Management Level ........................................................ 70 

Table 34. Cultivated Cropland Exceeding Resource Concern Thresholds by Survey......................................................................... 71 

Table 35. Percent Regional Acres Exceeding by Threshold, CEAP II * .............................................................................................. 72 

Table 36. Sediment Management Levels on Cultivated Cropland, CEAP I and CEAP II ....................................................................74 

Table 37. Sediment Management on Cultivated Cropland by Tillage System and CEAP Survey ..................................................... 76 

Table 38. Sediment Management Levels by Soil Vulnerability Index Runoff (SVI-R), CEAP I and CEAP II ........................................ 77 

Table 39. Nitrogen Management Levels on Cultivated Cropland, CEAP I and CEAP II.....................................................................78 

Table 40. Nitrogen Management on Cultivated Cropland by Tillage System and CEAP Survey ...................................................... 81 

Table 41. Nitrogen Management Levels by Soil Vulnerability Index Leaching, CEAP I and CEAP II ................................................. 82 

Table 42. Phosphorus Management Levels on Cultivated Cropland, CEAP I and CEAP II ................................................................ 83 

Table 43. Phosphorus Management on Cultivated Cropland by Tillage System and CEAP Survey.................................................. 86 

Table 44. Phosphorus Management on Cultivated Cropland by Soil Vulnerability Index Runoff (SVI-R) Rating, CEAP I and CEAP II 

......................................................................................................................................................................................................... 87 

Table 45. Estimated Percent of Cultivated Cropland Acres Meeting Resource Concern Thresholds under ENM, by Region........... 90 

Table 46. Cultivated Cropland by Conservation Treatment Level, CEAP I and CEAP II.....................................................................92 

Table 47. Losses on Cultivated Cropland by Treatment Level and Resource Concern, CEAP II ........................................................ 92 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland v 

Table 48. Estimated Loss Reduction from CEAP II Baseline, by Loss Type and Treatment Level...................................................... 93 

Table 49. Estimated Effects of ENM Treatment on Cultivated Cropland by Resource Concern and Treatment Need..................... 94 

Table 50. Progress toward ENM by Resource Concern, CEAP I and CEAP II..................................................................................... 95 

Figures 

Figure 1. Change in Cropland Acreage by Region, CEAP I to CEAP II * .............................................................................................. 2 

Figure 11. Percent of Cultivated Cropland with Conservation Crop Rotations by Biomass Index (BI) Level and Region, CEAP I and 

Figure 38. Cultivated Cropland Relative to Sediment-Transported Phosphorus Loss Threshold (Acres and Tons), CEAP I and CEAP 

Figure 2. CEAP Production Regions, Cropland Concentration, and Annual Average Precipitation.................................................... 3 

Figure 3. Change in Acreage of Selected Crops by Region and 12-Digit Hydrologic Unit, 2003–15 .................................................. 8 

Figure 4. Cultivated Cropland by Treatment Group, CEAP I and CEAP II.......................................................................................... 11 

Figure 5. Cultivated Cropland by Treatment Group and Region, CEAP I and CEAP II....................................................................... 12 

Figure 6. Structural Practices by Group, CEAP I and CEAP II............................................................................................................ 13 

Figure 7. Cultivated Cropland by Tillage Class, CEAP I and CEAP II.................................................................................................. 15 

Figure 8. HEL Cultivated Cropland by Treatment Group and Region, CEAP I and CEAP II................................................................ 19 

Figure 9. Cultivated Cropland with High and Moderately High SVI Runoff Rating by Treatment Group, CEAP I and CEAP II ......... 20 

Figure 10. Cultivated Cropland with No Structural Practices or Conservation Tillage by Region, CEAP I and CEAP II..................... 21 

CEAP II ............................................................................................................................................................................................. 24 

Figure 12. Cultivated Cropland by Combinations of Conservation Crop Rotations and Tillage, CEAP II .......................................... 24 

Figure 13. Cultivated Cropland with Cover Crops, CEAP I and CEAP II............................................................................................. 25 

Figure 14. Cover Crop Use on Cultivated Cropland by Region, CEAP II ............................................................................................ 27 

Figure 15. Acres of Irrigation on Cropland and Pastureland, 2017.................................................................................................. 28 

Figure 16. Change in Irrigated Cropland by Region, CEAP I to CEAP II*........................................................................................... 29 

Figure 17. Sources of Water for Irrigated Cropland, CEAP I and CEAP II ......................................................................................... 29 

Figure 18. Water Sources for Irrigated Cropland, Nationally and by Region, CEAP I and CEAP II ................................................... 31 

Figure 19. Irrigation Water Application Technology, Nationally and by Region, CEAP I and CEAP II ..............................................31 

Figure 20. National Irrigation Water Application Systems on Cropland, CEAP I and CEAP II........................................................... 32 

Figure 21. Most Prevalent Regional Irrigation Water Application Systems on Cropland, CEAP I and CEAP II................................. 32 

Figure 22. VISE Efficiency Scores in CEAP I and CEAP II and Most Prevalent Technology in CEAP II, by Region .............................. 33 

Figure 23. Irrigated Acreage Distribution of VISE Efficiencies by VISE Grouping and Region, CEAP I and CEAP II........................... 34 

Figure 24. Change in Nitrogen and Phosphorus Application Rates by Region, CEAP II minus CEAP I..............................................37 

Figure 25. Change in Incorporation Extent and Region, CEAP II minus CEAP I ................................................................................ 40 

Figure 26. Total Applied Nutrients by Timing and Incorporation, CEAP I and CEAP II .....................................................................41 

Figure 27. Nitrogen and Phosphorus Applied Load and Losses from Cultivated Cropland Receiving Manure Nutrients, CEAP II ... 43 

Figure 28. Nitrogen and Phosphorus Applied to Manured Acres by Source and Region, CEAP II .................................................... 44 

Figure 29. Seasonal Application of Manure Nutrients by Method, CEAP I and CEAP II ................................................................... 44 

Figure 30. Sheet and Rill Erosion on Cultivated Cropland Relative to Threshold, CEAP I and CEAP II..............................................48 

Figure 31. Cultivated Cropland Exceeding Sheet and Rill Erosion Threshold by SVI-R and CEAP Survey ......................................... 49 

Figure 32. Wind Erosion on Cultivated Cropland Relative to Threshold, CEAP I and CEAP II ........................................................... 52 

Figure 33. Cultivated Cropland Exceeding Wind Erosion Threshold by SVI-W and CEAP Survey ..................................................... 53 

Figure 34. Cultivated Cropland and Sediment Load Relative to Sediment Threshold (Acres and Tons), CEAP I and CEAP II ........... 54 

Figure 35. Cultivated Cropland Exceeding the Sediment Threshold by Region and SVI-R, CEAP I and CEAP II ................................ 56 

Figure 36. Cultivated Cropland Relative to Surface Nitrogen Loss Threshold (Acres and Tons), CEAP I and CEAP II ....................... 57 

Figure 37. Cultivated Cropland Exceeding the Surface Nitrogen Threshold by SVI-R and CEAP Survey........................................... 58 

II....................................................................................................................................................................................................... 60 

Figure 39. Cultivated Cropland Exceeding Sediment-Transported Phosphorus Threshold by Region and SVI-R, CEAP I and CEAP II 

......................................................................................................................................................................................................... 61 

Figure 40. Cultivated Cropland Relative to Subsurface Nitrogen Loss Threshold (Acres and Tons), CEAP II....................................63 

Figure 41. Cultivated Cropland Exceeding Subsurface Nitrogen Threshold by SVI-L and CEAP Survey............................................ 64 

Figure 42. Cultivated Cropland Relative to Soluble Phosphorus Loss Threshold (Acres and Tons), CEAP I and CEAP II................... 66 

Figure 43. Cultivated Cropland Exceeding Soluble Phosphorus Threshold by Region and SVI-R, CEAP I and CEAP II ...................... 67 

Figure 44. Cultivated Cropland by Carbon Trend, CEAP I and CEAP II.............................................................................................. 68 

Figure 45. Carbon Change by Region, CEAP I and CEAP II ............................................................................................................... 68 

Figure 46. Carbon Trends by Tillage Class, CEAP II .......................................................................................................................... 69 

Figure 47. Cultivated Cropland Exceeding the Carbon Threshold by Region and SVI-R, CEAP I and CEAP II....................................70 

Figure 48. Cultivated Cropland by Sediment Management Level, CEAP I and CEAP II.....................................................................74 

Figure 49. Sediment Management Levels on Cultivated Cropland by Region, CEAP I and CEAP II .................................................. 75 

Figure 50. Cultivated Cropland by Sediment Management Level and Tillage System, CEAP II minus CEAP I .................................. 76 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

vi Conservation Effects Assessment Project 

Figure 51. Change in Sediment Management on Cultivated Cropland by SVI-R, CEAP II minus CEAP I........................................... 78 

Figure 52. Cultivated Cropland by Nitrogen Management Level, CEAP I and CEAP II ..................................................................... 79 

Figure 53. Nitrogen Management Levels on Cultivated Cropland, CEAP I and CEAP II.................................................................... 80 

Figure 54. Nitrogen Management Level by Tillage System, CEAP II minus CEAP I........................................................................... 81 

Figure 55. Change in Nitrogen Management on Cultivated Cropland by SVI-L, CEAP II minus CEAP I ............................................ 83 

Figure 56. Cultivated Cropland by Phosphorus Management Level, CEAP I and CEAP II................................................................. 84 

Figure 57. Phosphorus Management on Cultivated Cropland by Region, CEAP I and CEAP II......................................................... 85 

Figure 58. Cultivated Cropland by Phosphorus Management Level and Tillage System, CEAP II minus CEAP I .............................. 86 

Figure 59. Change in Phosphorus Management on Cultivated Cropland by SVI-R, CEAP II minus CEAP I .......................................88 

Figure 60. Erosion and Sediment Progress Toward ENM, CEAP I and CEAP II ................................................................................. 96 

Figure 61. Progress toward Erosion and Sediment ENM by Loss Pathway and Region, CEAP II...................................................... 96 

Figure 62. Surface and Subsurface Nitrogen Progress Toward ENM, CEAP I and CEAP II................................................................ 97 

Figure 63. Progress toward Nitrogen ENM by Loss Pathway and Region, CEAP II .......................................................................... 98 

Figure 64. Total and Soluble Phosphorus Progress toward ENM, CEAP I and CEAP II ..................................................................... 98 

Figure 65. Progress toward Phosphorus ENM by Loss Pathway and Region, CEAP II...................................................................... 99 

Figure 66. Soil Carbon Progress toward ENM, CEAP I and CEAP II................................................................................................... 99 

Figure 67. Progress toward Soil Carbon ENM by Region, CEAP II..................................................................................................100 

Boxes 

Box 1. Structural Practice Groups and Types of Practices................................................................................................................ 13 

Box 2. Tillage Effects on Fuel Consumption and Greenhouse Gas Emissions................................................................................... 16 

Box 3. Soil Vulnerability Indexes...................................................................................................................................................... 18 

Box 4. Advances in Nutrient Technology ......................................................................................................................................... 36 

Box 5. Soil Testing for Nutrient Management ................................................................................................................................. 38 

Box 6. Controlling Erosion on Highly Erodible Land (HEL)................................................................................................................ 50 

Box 7. Cover Crop Benefits............................................................................................................................................................... 69 

Box 8. Treatment Needs at the Field Level ...................................................................................................................................... 72 
CEAP National Report: 

Conservation Practices on Cultivated 

Cropland 

INTRODUCTION 

The U.S. Department of Agriculture’s (USDA) Natural Resources Conservation Service (NRCS) 

evaluates conservation trends and effects on cultivated cropland through the multiagency 

Conservation Effects Assessment Project (CEAP), a sampling and modeling approach drawing 

on natural resource data and farmer surveys (appendix 1). The farmer surveys are conducted 

jointly by USDA’s NRCS and National Agricultural Statistics Service (NASS). The first surveys 

were completed in 2003–06 (CEAP I), with basinwide reports released from 2010 through 2014. 

Now, comparison data from the second set of farmer surveys (2013–16; CEAP II) make it 

possible to evaluate change over a decade. 

CEAP is intended to contribute to the science base for managing the agricultural landscape for 

environmental quality. Findings are intended to help guide conservation policy and program 

development and help conservationists, farmers, and ranchers in their conservation decisions. 

The purpose of this report is to present the CEAP I and CEAP II data on conservation practices 

applied on cultivated cropland at national and in some cases regional levels, estimates of the 

effects of these practices, and how conservation activity may have changed over the decade. The 

data reflect only the presence or absence of the practice; they do not indicate if the practice is 

pre-existing and maintained, reconstructed, or newly installed. 

CEAP Production Regions 

Estimates in this report are presented for 11 CEAP production regions, which reflect prevalent 

land use, cropping systems, climate, soil characteristics, and conservation practice use. The first 

CEAP reports (CEAP I) presented results by regions representing the major drainage basins in 

the United States (Water Resource Regions). The CEAP II regions reduce the variability in 

cropping systems, conservation and production practices, and resource concerns found in the 

CEAP I regions. The rules of analysis were unchanged between the CEAP survey periods, but 

the CEAP I sample points were reaggregated into the new regions presented in this report. For 

some regions with small amounts of cultivated cropland or where production systems and natural 

resource factors affect the opportunity or need for adoption of these practices, slight changes 

cannot be reliably estimated. 

Over the decade between the two CEAP survey periods, there was a small net gain in cultivated 

cropland of more than 2 million acres, primarily coming from pastureland and cropland exiting 
 

 

2 Conservation Effects Assessment Project 

the Conservation Reserve Program (CRP).1 Five regions gained almost 7.5 million cultivated 

cropland acres, while six regions lost about 5.3 million acres combined (fig. 1). By CEAP II, 

three regions (North Central and Midwest, Southern and Central Plains, and Northern Plains) 

accounted for three-fourths of all U.S. cultivated cropland (fig. 2; appendix 2, table A-1). 

Figure 1. Change in Cropland Acreage by Region, CEAP I to CEAP II 

Note: Number in parentheses indicates acreage change as a percent of the region’s CEAP I cultivated cropland level. 

The following provides generalized overviews of production and natural resource factors for 

each CEAP region to give context for the trends presented in this report. 

California Coastal: Cultivated cropland accounts for 3.9 million acres, less than 10 percent of 

the region’s total land area and about 1 percent of all cultivated cropland in the United States. 

Cultivated cropland is concentrated in the level to gently rolling valleys, which have lower 

vulnerability to wind and water erosion. With its dry Mediterranean climate, water management 

and irrigation practices are higher priorities than erosion control within fields or at their edges. 

Production on cultivated cropland is dominated by high-value crops such as rice, fruits, and 

vegetables. Production practices, pest and disease control measures, and industry requirements 

for the fresh market reduce producers’ ability to adopt conservation tillage on a continuous basis. 

1 See tables 6 and 7 of U.S. Department of Agriculture. 2020. Summary Report: 2017 National Resources Inventory, Natural 

Resources Conservation Service, Washington, DC, and Center for Survey Statistics and Methodology, Iowa State University, 

Ames, Iowa. https://www.nrcs.usda.gov/sites/default/files/2022-10/2017NRISummary_Final.pdf
Conservation Practices on Cultivated Cropland 3 

Figure 2. CEAP Production Regions, Cropland Concentration, and Annual Average Precipitation 

Note: The dot density shows concentrations of cultivated cropland within the region while the shading reflects the precipitation. 

Southwest: Cultivated cropland accounts for nearly 3.2 million acres, or less than 1 percent of 

the region’s total land area and less than 1 percent of all cultivated cropland in the United 

States. With an arid climate, water erosion vulnerability is low, while water management and 

irrigation practices are higher conservation priorities. Less than 10 percent of cultivated cropland 

acres have high or moderately high runoff risk when rains occur. Wind erosion is the primary 

erosion concern. High-tillage crops such as cotton, root crops, and vegetables along with land 

levelling and land shaping for irrigation limit adoption of continuous conservation tillage. 

Northwest: Cultivated cropland accounts for 13.4 million acres, but less than 5 percent of the 

region’s total land area and about 4 percent of all cultivated cropland in the United States. The 

region has a largely semiarid to arid climate that minimizes the need for water-induced erosion 

control. Wind erosion poses more of an erosion challenge. The significant increase in 

conservation tillage between the two CEAP survey periods is the primary wind-erosion-control 

measure. Wheat and other close-grown crops dominate cultivated cropland production and 

provide opportunities for the adoption of conservation tillage. Portions of the region where 

acreage is irrigated and root crops such as potatoes are produced have limited opportunities for 

continuous conservation tillage. 

Northern Plains: Cultivated cropland accounts for 51.1 million acres, or about 27 percent of 

the region’s total land area and about 16 percent of all cultivated cropland in the United States. 
 

 

4 Conservation Effects Assessment Project 

The region’s semiarid to subhumid climate, coupled with the fact that only about a fourth of the 

acres have high or moderately high runoff risk, reduces need for extensive structural practice 

adoption. In contrast, 44 percent of acres have a high or moderately high wind erosion risk, but 

the dominance of close-grown crops and conservation tillage provides significant control. 

Southern and Central Plains: Cultivated cropland accounts for 62.7 million acres, or about 28 

percent of the region’s total land area and about 20 percent of all cultivated cropland in the 

United States. With periods of seasonal drought and high-energy convective storms often 

producing high-intensity rainfall and flash floods, regional water quantity concerns need to be 

balanced with vegetated structural practices for wind and water erosion control. In the semiarid 

parts of the region, use of seasonal conservation tillage (e.g., crop rotations with small grains 

providing seasonal erosion control) is the primary wind erosion control method, while in the 

higher rainfall areas, structural conservation practice options are needed. The significant cotton 

acreage characterized by intense tillage, partially to control pests (e.g., boll weevil), reduces the 

viability of continuous conservation tillage in the southern part of the region. However, rotations 

with corn and small grains provide some seasonal tillage system flexibility. The northern part of 

the region is dominated by small grains conducive to conservation tillage adoption, although root 

crop (e.g., sugar beets) production here is also associated with intense tillage. 

North Central and Midwest: Cultivated cropland accounts for about 123.3 million acres, or 

about 44 percent of the region’s total land area and about 39 percent of all cultivated cropland 

in the United States. The region’s high-rainfall climate and the intensity of agricultural 

production drives higher adoption of one or more structural practices and conservation tillage to 

address multiple resource concerns. The sloping landscapes in the region may require more than 

one structural practice supported by conservation tillage, while conservation tillage alone may be 

adequate to control erosion in the lower lying areas, which tend to be drained and more prone to 

subsurface losses. The size and concentration of agriculture in this region significantly influences 

many of the national trends in adoption of structural practices and conservation tillage adoption. 

South Central: Cultivated cropland accounts for 5.1 million acres, or less than 5 percent of the 

region’s total land area and about 2 percent of all cultivated cropland in the United States. The 

generally sloping landscapes and humid, high-rainfall climate drives adoption of one or more 

structural conservation measures to control runoff. Cotton production in the region also reduces 

the opportunities for conservation tillage, resulting in the need for more than one structural 

practice on many acres to control erosion and sediment loss. 

Lower Mississippi and Texas Gulf Coast: Cultivated cropland accounts for 20.9 million acres, 

or nearly one-third of the region’s land area and about 7 percent of all cultivated cropland in 

the United States. The humid and subtropical climate, nearly flat slopes with tile drainage, and 

rolling loess hills adjacent to floodplains create conditions for excessive sediment loss and the 

need for multiple structural practices and minimal tillage practices with high-residue crop 

rotations. The prevalence of intense-tillage cotton and rice production reduces conservation 

tillage opportunities and increases reliance on structural practices. 

East Central: Cultivated cropland accounts for over 10.2 million acres, or about 17 percent of 

the region’s land area and about 3 percent of all cultivated cropland in the United States. The 
 

 

 

Conservation Practices on Cultivated Cropland 5 

humid climate with rolling topography often requires adoption of structural practices along with 

conservation tillage to control erosion and runoff. The high adoption of conservation tillage and 

particularly no-till reflect the dominance of corn-soybean-wheat rotations in the region. 

Atlantic and Gulf Coastal Plains: Cultivated cropland accounts for 13.8 million acres, just 

under 10 percent of the region’s land area and about 4 percent of all cultivated cropland in the 

United States. The humid, high-rainfall climate increases the need for edge-of-field structural 

practices to reduce losses on the two-thirds of acres with high to moderately high leaching risk, 

despite nearly level slopes. While less than 15 percent of acres have high or moderately high 

runoff risk, multiple structural practices generally are needed because of the high rainfall. The 

use of complex rotations with high-residue crops offset some effects associated with intense 

tillage systems on cotton and peanut production in the region, but structural practices are often 

necessary. 

Northeast: Cultivated cropland accounts for almost 7.6 million acres, just under 7 percent of the 

region’s land area and about 2 percent of all cultivated cropland in the United States. The 

northern part of the region has little cropland, and what is there is typically corn for silage and 

root and vegetable crops on hilly landscapes, which drives a need for multiple structural 

practices especially when conservation tillage is not used. The humid climate, more intense 

agriculture on hilly landscapes, and high proportion of acres receiving animal manures in the 

southern part of the region benefit from combinations of structural practices with conservation 

tillage. 

A Changing Agricultural Landscape 

Significant changes in agricultural management and production occurred over the decade in 

response to a variety of factors and provide additional context for the trends presented in this 

report. The changes are interrelated, manifesting in significant shifts in where crops are produced 

because of expanded growing seasons, advances in technology, and market signals. Moreover, 

the production environment continues to change; consider the current, historic drought 

conditions in the West and the continuing evolution of agri-environmental policies. 

Farms and Ownership 

The long-term shift toward larger, more specialized farms is part of a complex set of structural 

changes in agriculture. In the early 1980s, most cropland was operated by farms with less than 

600 crop acres, today most cropland is on farms with at least 1,100 acres. Field crop operations 

increasingly grow just two or three crops.2 

Specialization also separated crop and livestock production, which continued to shift toward 

larger, more geographically concentrated enterprises that produced no crops and relied on 

purchased feed. The geographic separation of livestock from cropland drove a nutrient imbalance 

between the two, reducing opportunities for manure nutrients to be used productively, and 

creating incentives for overapplication of manure nutrients as a waste disposal solution. 3,4 

2 https://www.ers.usda.gov/publications/pub-details/?pubid=45110 3 https://www.ers.usda.gov/publications/pub-details/?pubid=45110 4 https://www.ers.usda.gov/publications/pub-details/?pubid=44294 
 

 

 

 

 

6 Conservation Effects Assessment Project 

Despite shifts toward larger, more specialized farms, family farms continue to dominate crop 

agriculture. Family farms as a group accounted for 98 percent of farms and 86 percent of 

production in 2019. Most family farms are small;5 they operate almost one half of all farmland 

but account for only 22 percent of production. Large-scale family farms accounted for less than 3 

percent of farms, 21 percent of farmland, but 44 percent of the value of production.6 

While most of all U.S. farmland is owner-operated, more than half of cropland was rented in 

2017, compared with just over 25 percent of pastureland. In general, rental activity is 

concentrated in grain production areas; cash grains such as rice, corn, soybeans, wheat, and 

cotton.7 Most rented acres are owned by non-operator landlords, often with little connection to 

agriculture. 

Cropping Patterns 

Since the 1990s, U.S. farmers have been increasing corn and soybean acreage while decreasing 

acreage of other widely grown crops, particularly wheat. The Federal Agriculture Improvement 

and Reform (FAIR) Act of 1996 allowed farmers to change crops without loss of farm program 

eligibility, helping to ensure that crop acreage decisions would be based on market signals rather 

than farm program benefits. In the late 1990s, soybean acreage increased while wheat acreage 

decreased, reflecting changes in the relative profitability of these crops.8 

The shift accelerated in the late 2000s as increasing demand for feed and fuel and a spike in 

export demand led to higher corn and soybean prices. Relative to wheat, corn prices were 

particularly high, peaking at about 90 percent of wheat in 2010–12. Soybean prices were also 

high relative to wheat during this period, peaking at 195 percent of wheat prices in 2009–10. 

From 1992 to 2015, corn and soybeans increased from 41 percent to 54 percent of cultivated 

cropland nationally. Corn and soybean acreage increased in the western Corn Belt (Missouri, 

Iowa, Southwestern Minnesota, Eastern Nebraska, and Eastern South Dakota), the Great Plains 

(Texas, Oklahoma, Kansas, North Dakota, and Western South Dakota), the Northern and 

Northeastern states (Northwestern Minnesota, Wisconsin, Pennsylvania, and New York), and 

many parts of the South (fig. 3;pages 8 and 9 appendix 2, table A-2). Wheat acreage declined 

within traditional Corn Belt states (Ohio, Indiana, Illinois, Missouri, and Iowa) and along the 

eastern edge of the Great Plains (Texas, Oklahoma, Kansas, Nebraska, and the Dakotas), while 

increasing along the eastern seaboard and in some parts of Tennessee, Kentucky, and Alabama. 

Cotton production declined or was unchanged in all major cotton producing regions. 

Prevailing Weather 

Changes in temperature and precipitation altered growing conditions, making areas to the west 

and north of the traditional Corn Belt more favorable for corn and soybean production. In dryer 

regions, the moisture conservation benefits of conservation tillage (especially no-till) may have 

been important in expanding corn and soybean acreage. In the Great Plains and across the 

5 The Farm Typology developed by USDA’s Economic Research Service identifies small family farms as those with less than 

$350,000 in gross cash farm income. 

6 https://www.ers.usda.gov/publications/pub-details/?pubid=100011 7 https://www.ers.usda.gov/publications/pub-details/?pubid=74675 8 Zulauf, Carl and Melissa R. Wright. 2001. “The Law of Unintended Consequences.” Choices, Second Quarter: 20–24. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 7 

northern tier of states, growing seasons were 9 to 10 days longer, on average, during 1991–2012 

than during 1901–60.9 During similar time periods, in the eastern Great Plains, where lack of 

moisture has been a barrier to corn and soybean production, overall precipitation has increased 

by 10 to 20 percent. Further, the proportion of precipitation received in the heaviest 1 percent of 

precipitation events increased by 42 percent in the Northern Plains and by 24 percent in the 

Southern Plains.10 The increase in precipitation intensity may increase runoff, making some of 

the additional moisture unavailable to crops as well as increasing the potential for loss of 

sediment and nutrients from farm fields. 

Production Technology 

Advances in plant breeding technology, pest management, and other management techniques 

have increased productivity and production efficiencies. For example: 

● Continuous improvement in corn genetics have contributed to steady increases in corn yields. 

● Shorter season corn varieties, which can be grown at higher latitudes and depend less on lateseason moisture, helped expand corn production west and north. 

● Drought-tolerant varieties reduced the risk of crop loss in mild drought conditions and have been 

most widely used in states that experience relatively frequent periods of mild to moderate 

drought.11 

● The availability of herbicide tolerant (HT) corn and soybeans simplified weed control with 

reduced tillage, increasing the use of all types of conservation tillage.12 

However, the rapid advances in crop genetics have outpaced research on fertilizer 

recommendations, creating a lag that will tend to slow the realization of the environmental 

benefits of these more efficient crop genetics. 

The use of guidance systems on tractors, combines, and in other field operations has become 

more commonplace, accompanied by variable-rate fertilizer application technology that matches 

fertilizer rates to different soil zones and conditions within a field. Enhanced-efficiency 

fertilizers (EEF) include additives and formulations designed to control and better time the 

nutrient release of commercial fertilizers to meet crop demand and improve nutrient-use 

efficiency. The technology has largely been focused on nitrogen with the aim of reducing losses 

from ammonia volatilization and, after mineralization, to leaching, immobilization, and 

denitrification. These technologies make the farm operation more efficient in its fertilizer use and 

reduce potential losses. 

9 Walsh, J., D. Wuebbles, K. Hayhoe, J. Kossin, K. Kunkel, G. Stephens, P. Thorne, R. Vose, M. Wehner, J. Willis, D. Anderson, S. 

Doney, R. Feely, P. Hennon, V. Kharin, T. Knutson, F. Landerer, T. Lenton, J. Kennedy, and R. Somerville, 2014: Ch. 2: Our 

Changing Climate. Climate Change Impacts in the United States: The Third National Climate Assessment, J. M. Melillo, Terese 

(T.C.) Richmond, and G. W. Yohe, Eds., U.S. Global Change Research Program, 19-67. 10 Hayhoe, K., D.J. Wuebbles, D.R. Easterling, D.W. Fahey, S. Doherty, J. Kossin, W. Sweet, R. Vose, and M. Wehner, 2018: Our 

Changing Climate. In Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II 

[Reidmiller, D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and B.C. Stewart (eds.)]. U.S. Global 

Change Research Program, Washington, DC, USA, pp. 72–144. 11 McFadden, Jonathan, David Smith, Seth Wechsler, and Steven Wallander. 2019. “Development, Adoption, and Management 

of Drought-Tolerant Corn in the United States.” USDA Economic Research Service, Economic Information Bulletin EIB-204, 

November. 

12 Perry, Edward D., Gian Carlo Moschini, and David A. Hennessy. 2016. “Testing for Complementarity: Glyphosate Tolerant 

Soybeans and Conservation Tillage.” American Journal of Agricultural Economics 98 (3): 765–84. 
 

 

8 Conservation Effects Assessment Project 

Figure 3. Change in Acreage of Selected Crops by Region and 12-Digit Hydrologic Unit, 2003–15 
 

 

Conservation Practices on Cultivated Cropland 9 

Figure 3. Change in Acreage of Selected Crops by Region and 12-Digit Hydrologic Unit, 2003–15—Cont. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10 Conservation Effects Assessment Project 

HOW DID THE USE OF CONSERVATION PRACTICES CHANGE 

BETWEEN THE CEAP SURVEYS? 

In the decade between the CEAP surveys, adoption of structural practices and conservation 

tillage increased significantly, closely aligned with rising corn and soybean acreage. 

Conservation crop rotations were used on a majority of cultivated cropland, and the use of cover 

crops expanded. Irrigated cropland also increased, accompanied by efficiency gains that led to 

reduced water use. Nutrient management was challenged to keep pace with tillage and cropping 

changes and experienced some overall declines reflecting the complex interaction with 

conservation tillage systems. 

Structural Practices and Conservation Tillage 

Farmer adoption of structural practices (e.g., terraces, grassed waterways, see box 1, page 13) 

and conservation tillage, alone or in combination, increased by nearly 42 million acres 

nationwide between the two CEAP surveys. By CEAP II, one or more of these conservation 

practices were in place on over 81 percent of all cultivated cropland, up from 68 percent in 

CEAP I (table 1; appendix 2, table A-3). Acres without conservation tillage or structural 

practices declined significantly by 39.5 million acres to 19 percent of all cultivated cropland. 

Table 1. Structural Practices, Conservation Tillage, and Both on Cultivated Cropland, CEAP I and CEAP II 

Treatment Group 

CEAP I CEAP II CEAP II minus 

CEAP I * 

Percent 

Change in 

Acres 

Relative to 

CEAP I 

Acres 

(1,000s) 

Percent 

of Acres 

Acres 

(1,000s) 

Percent 

of Acres 

Acres 

(1,000s) 

Percent 

of Acres 

Structural Practices, Conservation 

Tillage, or Both 212,414 68 254,155 81 41,742 13 20 

Structural Practices plus Conservation 

Tillage 64,860 21 107,489 34 42,630 13 66 

Conservation Tillage Only 92,265 29 103,042 33 10,778 3 12 

Structural Practices Only 55,289 18 43,623 14 -11,666 -4 -21 

No Structural Practices or 

Conservation Tillage 100,651 32 61,148 19 -39,503 -13 -39 

National 313,065 100 315,303 100 2,238 

* Ninety-five-percent confidence intervals were constructed for each survey period; overlap of the intervals was considered to 

indicate no difference between the means. Unless noted, values fall within the 95-percent confidence interval. 

Structural Practices plus Conservation Tillage 

The greatest gains were made in the structural practices plus conservation tillage treatment 

group, evidence that farmers were increasingly integrating conservation management and 

structural treatments in a systems approach to improve results on their operations. By CEAP II, 

the combined practices had increased by 66 percent and were in place on over 107 million acres, 

or 34 percent of all cultivated cropland (fig. 4). 
 

 

Conservation Practices on Cultivated Cropland 11 

Figure 4. Cultivated Cropland by Treatment Group, CEAP I and CEAP II 

Adoption of structural practices and conservation tillage was highly concentrated in the North 

Central and Midwest and the Southern and Central Plains regions, which together accounted for 

about 72 percent of the total increase (fig. 5). Nationally, structural practices integrated with 

conservation tillage increased by 13 percentage points over the decade. 

Structural Practices 

Between CEAP I and CEAP II, an additional 31 million acres were benefited by structural 

practices, largely in combination with conservation tillage as the use of structural practices alone 

declined by 11.7 million acres (see box 1, page 13). By CEAP II, nearly half of all cultivated 

cropland acres had one or more structural practices in place (table 2; appendix 2, table A-4). 

Multiple structural practices accounted for 77 percent of the increase in adoption between CEAP 

I and CEAP II as farmers applied supporting practices in a systems approach to reduce soil 

erosion and related losses from cultivated cropland. More than half (56 percent) of the total 

national increase occurred in the North Central and Midwest region, where an additional 17.3 

million acres benefited from application of one or more structural practices. 

Of the five structural practice groups used on cultivated cropland (box 1), field borders (at least 

30 feet wide) experienced the largest acreage gain between the two survey periods as well as the 

largest percent gain relative to CEAP I implementation levels (fig. 6). Overland flow and 

concentrated flow control practices, however, maintained the largest footprint in both survey 

periods, reflecting their long history as erosion-control tools on farm fields (see also appendix 2, 

table A-5). 
 

 

12 Conservation Effects Assessment Project 

Figure 5. Cultivated Cropland by Treatment Group and Region, CEAP I and CEAP II 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 13 

Box 1. Structural Practice Groups and Types of Practices 

Five structural practice groups were established based on their primary conservation objective to facilitate evaluating change 

between the CEAP survey periods. The groups and example practices include: 

● Field border—Strips of permanent vegetation (grasses, legumes, forbs, or shrubs) established on one or more sides of a 

field 

● Edge-of-field buffering and filtering—Riparian forest buffers, riparian herbaceous buffers, filter strips, critical area 

planting 

● Wind erosion control—Windbreaks or shelterbelts, herbaceous wind barriers, hedgerow plantings 

● Concentrated flow control—Grassed waterways, grade stabilization structures, diversions, structures for water control 

● Overland flow control—Terraces, contour buffer strips, contour farming, stripcropping, in-field vegetative barrier. 

Table 2. Structural Practice Adoption, CEAP I and CEAP II 

CEAP I CEAP II CEAP II - CEAP I 

Cultivated Cropland with: Acres 

(1000s) Percent Acres (1000s) Percent Acres (1000s) Percent 

Percent 

Change in 

Acres 

Relative to 

CEAP I 

One or More Structural 

Practices 120,149 38 151,113 48 30,964 10 26 

One Type of Structural Practice 68,485 22 75,619 24 7,134 2 10 

More than One Type of Structural 

Practice 51,664 17 75,494 24 23,830 7 46 

Figure 6. Structural Practices by Group, CEAP I and CEAP II 

Note: CEAP II bar notations reflect the percent increase in acreage relative to the CEAP I implementation level. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

14 Conservation Effects Assessment Project 

Conservation Tillage 

The change in conservation tillage was particularly striking. Compared to conventional tillage, 

conservation tillage systems reduce soil disturbance, promote development of soil organic 

matter, reduce potential for compaction, and increase soil moisture holding capacity and 

infiltration, among other benefits. CEAP established five tillage classes based on average annual 

Soil Tillage Intensity Rating (STIR) values,13 which were placed into two groups for analysis: 

● Conservation Tillage 

o Reduced Tillage includes: 

▪ Continuous Mulch Tillage: All crops in the rotation are produced under tillage 

with STIR values for each crop between 20 and 80. Mulch tillage includes all 

forms of conservation tillage that are not considered no-till. 

▪ Seasonal No-Till: At least one crop is produced with no-till (STIR <20) and no 

crop in the rotation is conventionally tilled (STIR>80). 

o Continuous No-Till: All crops in the rotation are produced with tillage practices having 

STIR values <20. 

● Conventional Tillage 

o Continuous Conventional Tillage: All crops in the rotation are conventionally tilled 

(STIR >80). 

o Seasonal Conventional Tillage: At least one crop in the rotation is conventionally tilled 

(STIR>80) and at least one crop is conservation tilled (STIR<80). 

In the decade between the CEAP surveys, conservation tillage adoption increased by 53.4 

million acres (table 3; appendix 2, table A-6). Eighty percent of this increase was in combination 

with structural practices (see also table 1, page 10). By CEAP II, conservation tillage had 

become the dominant form of tillage, used on over two-thirds of all cultivated cropland (67 

percent). More than 41.5 million acres of the total increase was in continuous no-till, which 

reached 33 percent of all cultivated cropland acres by CEAP II (fig. 7). As a result, farmers were 

able to reduce annual average fuel consumption in tillage processes by 110 million gallons of 

diesel fuel equivalents and avoid the associated annual greenhouse gas emissions by nearly 1.2 

million tons of carbon dioxide equivalents (CO2-eq) by CEAP II (see box 2, page 16). 

Table 3. Tillage Groups and Classes, CEAP I and CEAP II 

Tillage Group / Tillage 

Class 

CEAP I CEAP II CEAP II minus 

CEAP I * 

Percent 

Change in 

Acres 

Relative to 

CEAP I 

Acres 

(1,000s) Percent Acres (1,000s) Percent Acres (1,000s) Percent 

Conservation Tillage 157,124 50 210,532 67 53,408 17 34 

Continuous Mulch 50,631 16 60,212 19 9,581 3 19 

Seasonal No Till 44,941 14 47,211 15 2,271 1 5 

Continuous No-Till 61,553 20 103,108 33 41,556 13 68 

Conventional Tillage 155,941 50 104,771 33 -51,169 -17 -33 

Continuous Conventional 62,922 20 42,052 13 -20,869 -7 -33 

Seasonal Conventional 93,019 30 62,719 20 -30,300 -10 -33 

* Ninety-five-percent confidence intervals were constructed for each survey period; overlap of the intervals was considered to 

indicate no difference between the means. Unless noted, values meet the 95-percent confidence interval. 

13 STIR is a function of the type, frequency, and depth of tillage and calculates soil disturbance intensity for each 

crop grown in a crop rotation. The higher the rating, the greater the soil disturbance and erosion potential. 
 

 

Conservation Practices on Cultivated Cropland 15 

Figure 7. Cultivated Cropland by Tillage Class, CEAP I and CEAP II 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16 Conservation Effects Assessment Project 

Box 2. Tillage Effects on Fuel Consumption and Greenhouse Gas Emissions 

Among the many benefits of conservation tillage systems as compared to conventional tillage are the reductions in the number 

of field operations and associated soil disturbance, fuel consumption, and greenhouse gas emissions. Between CEAP I and CEAP 

II, cultivated cropland increased by over 2 million acres, conservation tillage systems increased by over 53 million acres, and 

conventional tillage systems declined by over 51 million acres. Correspondingly, fuel use grew in conservation tillage and 

dropped in conventional tillage. The upshot is that by CEAP II, farmers were cultivating slightly more cropland while using less 

fuel and producing fewer emissions; annual fuel consumption on all cultivated cropland declined by 110 million gallons of diesel 

fuel equivalents and annual emissions declined by nearly 1.2 million tons of carbon dioxide equivalents (CO2-eq). 

Fuel Use and Emissions by Tillage System, CEAP I to CEAP II 

Tillage System 

CEAP I (2003–06) CEAP II (2013–16) CEAP II minus CEAP I 

Acres\ 

(Million) 

Total Fuel 

Consumption 

(Million gallons 

Diesel equiv.) 

Acres\ 

(Million) 

Total Fuel 

Consumption 

(Million gallons 

Diesel equiv.) 

Fuel 

Consumption 

(Million gallons 

Diesel equiv.) 

Emissions 

Reductions 

(Million tons 

CO2 equiv)** 

Continuous Conventional 62.9 340.0 42.1 226.0 -114.0 -1.3 

Seasonal Conventional * 93.0 328.0 62.7 226.0 -102.0 -1.1 

Reduced Tillage 95.5 266.0 107.4 298.0 32.0 0.4 

Continuous No Till 61.6 114.0 103.1 188.0 74.0 0.8 

Total 313.1 1,048.0 315.3 938.0 -110.0 -1.2 

* Seasonal conventional is presented separately here because of differences in fuel consumption compared to continuous 

conventional tillage. 

** Based on 22.4 pounds of CO2-eq per gallon of diesel fuel equivalents. 

Assuming uniform transition over the decade, the adoption of conservation tillage had an estimated cumulative effect of 

reducing: 

● Fuel consumption by up to 600 million gallons of diesel fuel equivalents, enough to meet the annual electricity 

requirements of nearly 2.3 million average households in the United States.14 

● Emissions by up to 6.6 million tons of CO2-eq., enough to offset the annual CO2-eq emissions of about 1.4 million 

passenger cars, or nearly all the passenger cars registered in the state of Louisiana.15 

● Fuel costs borne by farmers by up to $1.8 billion.16 

These effects, however, mask the significant difference between conservation tillage and continuous conventional tillage in 

terms of fuel use and emissions. If the nearly 273 million acres of cultivated cropland under conservation tillage and seasonal 

conventional systems in CEAP II had been under continuous conventional tillage, it would have required an additional 763 

million gallons of diesel fuel equivalents per year, and that additional fuel would have had associated emissions of roughly 8.5 

million tons of CO2-eq. For context, the additional fuel is equal to the annual energy needed for over 2.8 million average 

households in the United States.17 The associated CO2-eq emissions is equal to that of nearly 1.7 million passenger cars, or 

slightly less than all the passenger cars in the state of Colorado. 18 

14 As calculated by converting the estimated diesel fuel equivalents reduced to kilowatt hours. According to the U.S. Energy 

Information Administration the average household electricity use is 10,649 kWh annually. 

https://www.eia.gov/energyexplained/units-and-calculators/energy-conversion-calculators.php 15 Based on emissions from an average passenger vehicle, https://www.epa.gov/energy/greenhouse-gas-equivalenciescalculator. Number of passenger vehicles as reported in 2015 according to data from the Federal Highway Administration. 

https://www.fhwa.dot.gov/policyinformation/statistics/2015/mv1.cfm 

16 Based on an average price of $2.94 per gallon for diesel fuel between 2003 and 2016, as reported by the U.S. Energy 

Information Administration. https://www.eia.gov/dnav/pet/pet_pri_gnd_dcus_nus_a.htm 17 As calculated by converting the estimated diesel fuel equivalents reduced to kilowatt hours. According to the U.S. Energy 

Information Administration the average household electricity use is 10,649 kWh annually. 

https://www.eia.gov/energyexplained/units-and-calculators/energy-conversion-calculators.php 18 Based on emissions from an average passenger vehicle, https://www.epa.gov/energy/greenhouse-gas-equivalenciescalculator. Number of passenger vehicles as reported in 2015 according to data from the Federal Highway Administration. 

https://www.fhwa.dot.gov/policyinformation/statistics/2015/mv1.cfm 
 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 17 

And farmers would have faced between $1.8 billion and $3 billion in additional fuel costs.19 Roughly 80 percent of that 

additional fuel need would have been concentrated in three regions—North Central and Midwest, Northern Plains, and 

Southern and Central Plains. 

Estimated Annual Reduction in Fuel Use and Emissions by Conservation Tillage and Seasonal Conventional Tillage Systems as 

Compared to Continuous Conventional Tillage, CEAP II 

Tillage Type Cultivated Cropland Total Fuel Average Fuel Use Avoided Emissions Avoided 

Acres Acres Consumption Fuel (Million gallons (Million tons CO2 

(Millions (Percent (Million gallons Use/Acre Diesel equiv.)* equiv) **

) Diesel equiv.) 

Continuous Conventional 42.1 13.4 226.0 5.4 - -

Seasonal Conventional 62.7 19.9 226.0 3.6 112.6 1.3 

Reduced Tillage 107.4 34.1 298.0 5.5 282.0 3.2 

Continuous No Till 103.1 32.7 188.0 1.8 368.7 4.1 

Total 315.3 100.0 938.0 16.3 763.3 8.5 

* Potential annual reduction in fuel consumption as compared to a continuous conventional tillage system with STIR >80. 

** Based on 22.4 pounds of CO2-eq per gallon of diesel fuel equivalents. 

The Southern and Central Plains, characterized by winter wheat and other close-grown small 

grains, accounted for 40 percent of the total increase in conservation tillage adoption. The North 

Central and Midwest region (dominated by corn and soybean production) accounted for another 

31 percent. Nationally, conservation tillage adoption increased by 17 percentage points between 

the survey periods. That gain was exceeded in four regions, with the Southern and Central Plains 

region being twice the national average. 

Structural Practices and Conservation Tillage on Vulnerable Cropland 

The cultivated cropland most vulnerable to excessive soil erosion (Highly Erodible Land [HEL]) 

and runoff (high and moderately high Soil Vulnerability Index [SVI] runoff) account for about 

27 percent and 29 percent of all cultivated cropland, respectively (box 3). Conservation adoption 

on these acres emphasized structural practices in combination with conservation tillage. In 

addition, these vulnerable acres received a slightly higher proportion of treatment compared to 

their less vulnerable counterparts. By CEAP II, structural practices or conservation tillage, or 

both, were in place on 85 percent of HEL cultivated cropland and on over 90 percent of 

cultivated cropland with high or moderately high runoff vulnerability, as compared to 81 percent 

for all cultivated cropland. 

Highly Erodible Land—The 1985 Farm Bill introduced policy to encourage conservation on 

cropland deemed to be the most susceptible to excessive erosion (Highly Erodible Land [HEL]) 

by linking farm program eligibility to implementation of soil conservation measures. Between 

CEAP I and CEAP II, adoption of structural practices plus conservation tillage on HEL increased 

by 13.9 million acres (63 percent) (table 4, fig. 8; appendix 2, table A-7). Use of conservation 

tillage without structural practices also increased by nearly 6.8 million acres (32 percent), while 

use of structural practices alone declined by 4.9 million acres (35 percent). Adoption of these 

practices increased by 12 percentage points over the decade, despite a 7.4-million-acre increase 

in HEL under cultivation. 

19 Based on average prices of $3.9 per gallon for diesel fuel in 2013 and $2.4 per gallon in 2016, as reported by the U.S. Energy 

Information Administration. https://www.eia.gov/dnav/pet/pet_pri_gnd_dcus_nus_a.htm 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

18 Conservation Effects Assessment Project 

Box 3. Soil Vulnerability Indexes 

NRCS developed Soil Vulnerability Indexes (SVI) in the 2000s to support conservation planning through rigorous assessment of 

soil vulnerability to the forces of water (runoff, leaching) and wind. SVI uses current information on soil properties as well as 

other aspects of vulnerability such as slope and drainage. Four ratings (low, moderate, moderately high, and high) are used to 

categorize a soil’s potential vulnerability. The index is regionally relative; for example a high runoff rating in an arid region 

would not have the same conservation need as a high runoff rating in a humid region. Examining cropland by potential 

vulnerability offers an important tool for identifying conservation needs and supporting conservation planning from the field to 

regional and national scales. 

Between the CEAP surveys, cultivated cropland with moderately high and high runoff vulnerability increased by nearly 11 

million acres. For cultivated cropland vulnerable to leaching, the only increase was in low vulnerability acres at nearly 12.5 

million acres although it remained the smallest rating category. Cultivated cropland with moderately high wind vulnerability 

increased by 4 million acres, while the rest of the rating categories declined. 

Across the three vulnerability indexes, wind and runoff vulnerability have a similar distribution of acres among the rating 

categories, with most acres having low vulnerability and least acres having high vulnerability. The distribution for leaching 

vulnerability is nearly the opposite with most acres having a moderate or high rating. In CEAP II, nearly 30 percent of cultivated 

cropland had high vulnerability to leaching as compared to 11 percent for runoff vulnerability and 1 percent for wind 

vulnerability. 

Cultivated Cropland by Soil Vulnerability Index Type and Rating, CEAP I and CEAP II 

Table 4. Highly Erodible Cropland by Treatment Group, CEAP I and CEAP II 

Treatment Group 

CEAP I CEAP II CEAP II - CEAP I 

Acres 

(1000s) Percent HEL Acres (1000s) 

Percent 

HEL 

Acres 

(1000s) Percent HEL 

Percent Acres 

Relative to 

CEAP I 

Structural Practices, Conservation Tillage, 

or Both 57,262 73 72,985 85 15,722 12 27 

Structural Practices plus Conservation 

Tillage 21,971 28 35,862 42 13,891 14 63 

Conservation Tillage Only 21,164 27 27,926 33 6,762 6 32 

Structural Practices Only 14,127 18 9,197 11 -4,930 -7 -35 

No Structural Practice(s) or Conservation 

Tillage 21,155 27 12,800 15 -8,355 -12 -39 

National 78,417 100 85,785 100 7,367 9 
 

 

Conservation Practices on Cultivated Cropland 19 

Figure 8. HEL Cultivated Cropland by Treatment Group and Region, CEAP I and CEAP II 
 

 

 

 

 

 

 

 

20 Conservation Effects Assessment Project 

Cropland Vulnerable to Runoff—On the cultivated cropland most vulnerable to runoff (high 

and moderately high SVI runoff categories), adoption of structural practices plus conservation tillage 

increased by a combined 20.8 million acres between the CEAP surveys (table 5; appendix 2, table A-8). 

By CEAP II, the combined practices on high and moderately high vulnerability acres increased by 81 and 

74 percent, respectively (fig. 9). Use of conservation tillage alone increased by a small amount, about 1.3 

million acres. Adoption of structural practices alone declined by 4.4 million acres. 

Table 5. Cultivated Cropland with High and Moderately High Runoff (SVI) Ratings by Treatment Group, 

CEAP I and CEAP II 

Treatment Group 

CEAP I CEAP II CEAP II - CEAP I 

Acres 

(1,000s) Percent Acres (1,000s) Percent Acres (1,000s) Percent 

Percent of Acres 

Relative to 

CEAP I 

Structural Practices, Conservation 

Tillage, or Both 

High 23,453 86 31,340 93 7,887 7 34 

Moderately High 42,250 79 52,114 90 9,864 11 23 

Structural Practices plus Conservation 

Tillage 

High 11,605 43 20,974 63 9,370 20 81 

Moderately High 15,497 29 26,898 46 11,401 17 74 

Conservation Tillage Only 

High 6,706 25 6,877 21 171 -4 3 

Moderately High 16,268 30 17,436 30 1,169 0 7 

Structural Practices Only 

High 5,143 19 3,489 10 -1,654 -9 -32 

Moderately High 10,485 20 7,779 13 -2,706 -6 -26 

No Structural Practices or 

Conservation Tillage 

High 3,692 14 2,192 7 -1,500 -7 -41 

Moderately High 11,471 21 6,051 10 -5,420 -11 -47 

National 

High 27,145 9 33,532 11 6,387 2 24 

Moderately High 53,721 17 58,165 18 4,444 1 8 

Figure 9. Cultivated Cropland with High and Moderately High SVI Runoff Rating by Treatment Group, 

CEAP I and CEAP II 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 21 

Cultivated Cropland with No Structural Practices or Conservation Tillage 

As of CEAP II, some 61.1 million acres (19 percent) of cultivated cropland had neither structural 

practices nor conservation tillage in place, down from 100.7 million acres (39 percent) in CEAP 

I (fig. 10). Four regions (North Central and Midwest, Southern and Central Plains, Northern 

Plains, and Lower Mississippi and Texas Gulf Coast) accounted for 74 percent of the cultivated 

cropland without structural practices or conservation tillage. 

Figure 10. Cultivated Cropland with No Structural Practices or Conservation Tillage by Region, CEAP I and 

CEAP II 

Conservation needs may be low on the acres without structural practices or conservation tillage, 

or addressed through other measures (such as rotations or cover crops). However, treatment may 

be particularly important on untreated acres highly vulnerable to erosion and/or runoff, or where 

high rainfall intensifies potential soil losses. For example, of the total acreage lacking structural 

practices or conservation tillage, 12.8 million acres were HEL and 8.2 million acres had high or 

moderately high vulnerability to runoff (table 6). 

Table 6. Cultivated Cropland with No Structural Practices or Conservation Tillage, CEAP I and CEAP II 

Cultivated Cropland Group 

CEAP I CEAP II CEAP II minus CEAP I Percent 

Change in 

Acres 

Relative to 

CEAP I 

Acres 

(1,000s) 

Percent 

Acres 

Acres 

(1,000s) 

Percent 

Acres 

Acres 

(1,000s) 

Percent 

Acres 

All Cultivated Cropland 100,651 32 61,148 19 -39,503 -13 -39 

Highly Erodible Land 21,155 27 12,800 15 -8,355 -12 -39

Percent of All Acres with No 

Structural Practices or 

Conservation Tillage 

21 21 

High and Moderately High 

Runoff Vulnerability 15,163 19 8,243 9 -6,920 -10 -46 

Percent of All Acres with No 

Structural Practices or 

Conservation Tillage 

15 13 
 

 

 

22 Conservation Effects Assessment Project 

Conservation Crop Rotations and Cover Crops 

Conservation crop rotations and cover crops have a common goal of reducing erosion through 

covering or protecting the soil. A conservation crop rotation is a planned sequence of crops 

grown on the same field over a period of time to achieve a conservation purpose, such as 

reducing erosion or improving soil organic matter content. Cover crops are generally a grass, 

small grain, or legume planted specifically to provide vegetative cover during the non-growing 

season. Including cover crops, perennials, and winter annuals in a crop rotation provides yearround soil cover, and a variety of benefits such as promoting soil structure, taking up nutrients 

that may otherwise be lost, and enhancing habitat for wildlife, including pollinators. Some 

cropping systems and environments, however, are less conducive to the use of cover crops in 

rotation, for example in arid or semiarid environments where additional water may be needed to 

maintain productivity or where growing seasons are short. Technologies such as interseeding 

before harvest can help to overcome challenges to late-season establishment of cover crops in 

colder climates. 

Conservation Crop Rotations 

By CEAP II, nearly 70 percent of cultivated cropland acres had conservation crop rotations, up 

from 66 percent in CEAP I, including 28 percent of all cultivated cropland acres having highbiomass conservation crop rotations (table 7; appendix 2, table A-9). For this report, 

conservation crop rotations had to meet a biomass index score of 1.5 or higher; rotations with a 

biomass index of 2.0 or higher were identified as high-biomass conservation crop rotations. 20 As 

expected, high-biomass conservation crop rotations are concentrated in rotations with hay—84 

percent of acres with hay in the rotation had high-biomass crop rotations—but only 16 percent of 

acres with continuous row crop rotations were high-biomass conservation crop rotations. 

About 31 percent of cultivated cropland acres (96.2 million acres) did not have a conservation 

crop rotation in CEAP II. These acres, however, are not equally distributed among the four major 

crop rotation groups. Only 11 percent of rotations that included hay were not in a conservation 

crop rotation. In contrast, 51 percent of rotations with only close-grown crops were not in a 

conservation crop rotation. While only 27 percent of rotations that included only continuous row 

crops were not in a conservation crop rotation, that group accounted for over half of the total 

acres without conservation crop rotations. 

Of the 96 million acres without conservation crop rotations, 40 percent included an idle or fallow 

year, which contributes little or no biomass to the rotation. These years were planned resting 

periods to allow the soil to build up water or nutrient reserves or were idled because of external 

conditions such as poor weather, natural disasters, or economic hardship. Ninety-eight percent 

of rotations that included only close-grown crops and 69 percent of rotations that included hay 

had an idle or fallow year in the rotation. 

20 The biomass index assigns a score to each crop in a rotation based on the level of biomass produced (high, moderately high, 

moderately low, low, and idle/fallow), and then averages these scores over the rotation to produce a single score. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 23 

Table 7. Cultivated Cropland by Crop Rotation Group, CEAP II 

Crop 

Rotation 

Group 

Cultivated 

Cropland 

With Conservation Crop Rotations Without Conservation Crop 

Rotations 

All* High-Biomass** All 

With Idle or Fallow 

in One or More 

Rotation Years 

Acres 

(1,000) Percent Acres (1,000s) Percent Acres (1,000s) Percent Acres 

(1,000s) Percent Acres 

(1,000s) Percent 

Hay With 

Other Crops 20,787 7 18,459 89 17,503 84 2,328 11 1,599 69 

Close-grown 

Crops, No Hay 

or Row Crops 

47,289 15 23,077 49 20,287 43 24,212 51 23,631 98 

Row and 

Close-grown 

Crops, No Hay 

65,719 21 44,689 68 19,650 30 21,030 32 8,517 41 

Continuous 

Row Crops 181,509 58 132,865 73 29,223 16 48,644 27 4,183 9 

All Cultivated 

Cropland 315,303 100 219,136 70 86,708 28 96,167 31 37,986 40 

* Acres with a crop rotation biomass index score greater than or equal to 1.5. 

** Acres with a crop rotation biomass index score greater than or equal to 2.0. 

All production regions except for the Northwest, South Central, and Southern and Central Plains 

experienced an increase in conservation crop rotations between the CEAP surveys (fig. 11). 

Specifically: 

● Use of high biomass conservation crop rotations increased in all but four regions—Northern 

Plains, Northwest, South Central, and Southern and Central Plains. 

● Four regions—North Central and Midwest, Northeast, East Central, and South Central— 

exceeded the national average of nearly 70 percent of cultivated cropland acres in conservation 

crop rotations. The latter three also had 40 percent or more of their cultivated cropland in highbiomass conservation crop rotations. 

● Three regions—California Coastal, Northern Plains, and Southern and Central Plains—were 

below the CEAP II national average but still had more than half of their regional cultivated 

cropland in conservation crop rotations. 

● Half or fewer of the cultivated cropland acres in four regions—Atlantic and Gulf Coastal Plains, 

Southwest, Lower Mississippi and Texas Gulf Coast, and Northwest—were in conservation crop 

rotations. 

Conservation crop rotations used in combination with conservation tillage can provide even 

better protection against runoff and soil loss. Nearly half of all cultivated cropland acres have 

combinations of conservation tillage and conservation crop rotations and another 21 percent have 

conservation crop rotations but are conventionally tilled (fig 12). 

Continuous row crops accounted for most cultivated cropland acres and most acres with 

conservation crop rotations and conservation tillage (55 percent). Cultivated cropland with 

continuous close-grown crops had the lowest percent of acres with conservation crop rotations 

and conservation tillage (29 percent). The most common close-grown crop rotations were corn 

and wheat, soybean and wheat, corn and soybean and wheat, rice and soybean, and wheat and 

sorghum. Not surprisingly, hay with other crops in rotation, while the smallest share of cultivated 

cropland (7 percent), had most acres meeting the definition of conservation crop rotation (88 

percent) (table 8). 
 

 

 

 

 

 

 

 

 

 

 

 

24 Conservation Effects Assessment Project 

Figure 11. Percent of Cultivated Cropland with Conservation Crop Rotations by Biomass Index (BI) Level 

and Region, CEAP I and CEAP II 

Figure 12. Cultivated Cropland by Combinations of Conservation Crop Rotations and Tillage, CEAP II 

Table 8. Cultivated Cropland by Crop Rotation Group and Tillage Group, CEAP II 

Crop Rotation Group 

Cultivated 

Cropland 

Tillage Group 

Conventional Tillage Reduced Tillage Continuous No-Till 

Conservation Crop Rotation Status 

With Without With Without With Without 

Acres 

(1,000s) Percent Crop Rotation Group Acres 

Hay with other crops 20,787 45.3 3.9 22.6 2.6 20.8 4.8 

Continuous Close-grown 

crops, no hay or row crops 47,289 19.6 17.1 12.7 11.5 16.5 22.7 

Row and close-grown crops, 

no hay 65,719 22.4 11.9 18.7 8.8 26.8 11.4 

Continuous Row crops, 

no close-grown crops or hay 181,509 18.1 12.0 31.9 8.2 23.2 6.6 

National 315,303 21.0 12.2 25.6 8.4 22.8 9.9 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 25 

Cover Crops 

Between CEAP I and CEAP II, farmers’ use of cover crops increased from slightly over 2 

million acres to nearly 19 million acres, yet cover crops were still used on only about 6 percent 

of total cultivated cropland in CEAP II. Cover crop adoption between the two surveys was highly 

concentrated in three regions—Atlantic and Gulf Coastal Plains, North Central and Midwest, and 

Northern Plains—where 70 percent of the increase occurred (fig. 13). 

Cover crops were more prevalent among continuous row crop rotations, which accounted for 58 

percent of cultivated cropland acres but 68 percent of the acres with cover crops in one or more 

years of the rotation (table 9). In CEAP II, about 7 percent of continuous row crop acres included 

cover crops. 

Nearly all acres with cover crops—94 percent—also had conservation crop rotations, in part due 

to the biomass contribution of the cover crops (table 10). About 84 percent of the acres with 

cover crops had high-biomass conservation crop rotations, which included high-biomass crops 

such as hay (other than small-grain hay), grasses, grass seed, and wild rice. About 1.1 million 

acres that included cover crops in the rotation did not meet the biomass index threshold (i.e., 

biomass index of 1.5 or greater) to be designated as a conservation crop rotation. 

Figure 13. Cultivated Cropland with Cover Crops, CEAP I and CEAP II 

Table 9. Use of Cover Crops in Major Crop Rotation Groups, CEAP II 

Crop Rotation Group 

Cultivated 

Cropland 

Cover 

Crops 

Average Crop 

Years with 

Cover Crops* 

Group Acres 

with Cover 

Crops 

Group Share 

of All Cover 

Crops 

Acres (1,000s) Percent 

National 315,303 18,900 56 6.0 100.0 

Hay with Other Crops 20,787 1,409 44 6.8 7.5 

Continuous Close-grown Crops, No Hay or 

Row Crops 47,289 654 45 1.4 3.5 

Row and Close-grown Crops, No Hay 65,719 3,996 47 6.1 21.1 

Continuous Row Crops 181,509 12,840 61 7.0 67.9 

* For sample points with rotations that included cover crops, the number of years in the rotation that had cover crops was 

divided by the number of years in the full rotation. This proportion was then averaged over all the sample points with cover crops 

and reported here as an average percentage. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

26 Conservation Effects Assessment Project 

Table 10. Cover Crops and Conservation Crop Rotations by Major Crop Rotation Group, CEAP II 

Crop Rotation Group 

Cultivated 

Cropland with 

Cover Crops 

Cover Crop Acres 

with Conservation 

Crop Rotation 

Cover Crop Acres with 

High-Biomass 

Conservation Crop 

Rotation 

Acres (1,000s) Percent Percent 

National 18,900 94.2 83.8 

Hay with Other Crops 1,409 94.0 90.7 

Close-grown Crops, No Hay or Row Crops 654 83.6 77.0 

Row and Close-grown Crops, No Hay 3,996 93.1 78.9 

Row crops, No Close-grown Crops or Hay 12,840 95.1 84.9 

About 6 percent of cultivated cropland acres included cover crops in one or more years of the 

rotation in CEAP II. Cover crop use in the Northeast, Atlantic and Gulf Coastal Plains, and East 

Central regions was substantially higher than the national average, accounting for 30 percent of 

acres with cover crops in the rotation while accounting for only 10 percent of all cultivated 

cropland acres (table 11). 

Table 11. Cover Crop Use by Region, CEAP II 

Production Region 

Cultivated 

Cropland 

Cover 

Crops 

Regional 

Cultivated 

Cropland 

Regional 

Acres with 

Cover Crops 

Regional Share 

of All Cover 

Crop Acres 

Acres (1,000s) Percent 

National 315,303 18,900 100 6 100 

Atlantic and Gulf Coastal Plains 13,825 2,587 4 19 14 

California Coastal 3,913 169 1 4 1 

East Central 10,166 1,511 3 15 8 

Lower Mississippi and Texas Gulf 

Coast 20,916 506 7 2 3 

North Central and Midwest 123,296 7,815 39 6 41 

Northeast 7,597 1,611 2 21 9 

Northern Plains 51,130 1,995 16 4 11 

Northwest 13,438 227 4 2 1 

South Central 5,107 170 2 3 1 

Southern and Central Plains 62,732 2,231 20 4 12 

Southwest 3,183 77 1 2 0 

Cover crop use in the North Central and Midwest region was close to the national average with 

about 6.3 percent of cultivated cropland with cover crops in rotation, although that region 

accounted for 41 percent of all cultivated cropland acres with cover crops nationally (fig 14). All 

other regions were below the national average. Humid and subhumid production regions 

generally have adequate precipitation and infiltration to replenish soil water used by cover crops. 

The low use of cover crops in certain production regions (California Coastal, Lower Mississippi 

and Texas Gulf Coast, Northwest, South Central, and Southwest) reflects the arid or semi-arid 

conditions or water intensive production systems (e.g., rice) where additional water is needed to 

maintain productivity.21, 22, 23 

21 Eash, L., Berrada, A.F., Russell, K. and Fonte, S.J., 2021. Cover Crop Impacts on Water Dynamics and Yields in Dryland Wheat 

Systems on the Colorado Plateau. Agronomy, 11(6), p.1102. 

22 Nielsen, D.C., Lyon, D.J., Hergert, G.W., Higgins, R.K., Calderón, F.J. and Vigil, M.F., 2015. Cover crop mixtures do not use 

water differently than single-species plantings. Agronomy Journal, 107(3), pp.1025-1038. 23 Unger, P.W. and Vigil, M.F., 1998. Cover crop effects on soil water relationships. Journal of Soil and Water Conservation, 

53(3), pp. 200-206. 
 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 27 

Figure 14. Cover Crop Use on Cultivated Cropland by Region, CEAP II 

Irrigation 

About 49.7 million cropland acres were irrigated by CEAP II, an increase of 4.9 million acres 

(11 percent) over the CEAP I level (table 12). Irrigated acres are concentrated where the practice 

is either required for production because of low precipitation, where it enables more profitable 

crops, where water supplies are available, and where producers view the capital expense as a 

sound production investment (fig. 15). Over two-thirds of irrigated acreage is in three regions— 

Southern and Central Plains (34 percent), Lower Mississippi and Texas Gulf Coast (23 percent), 

and North Central and Midwest (10 percent). 

Table 12. Total Cropland, Irrigated Cropland, and Change in Irrigated Acres, CEAP I and CEAP II, 

Nationally and by Region 

Geographic Area 

CEAP I CEAP II 

Change in Acres Total 

Cropland 

Acres 

(1,000s) 

Irrigated 

Cropland 

Acres 

(1,000s) 

Percent 

Irrigated 

Total 

Cropland 

Acres 

(1,000s) 

Irrigated 

Cropland 

Acres 

(1,000s) 

Percent 

Irrigated (1,000s) Percent 

National 313,065 44,802 14 315,303 49,711 16 4,909 11 

Southern and Central Plains 64,337 15,564 24 62,732 16,778 27 1,214 8 

Lower Mississippi and Texas Gulf Coast 21,816 8,970 41 20,916 11,651 56 2,681 30 

North Central and Midwest 120,134 3,857 3 123,296 5,218 4 1,362 35 

Northwest 14,010 5,156 37 13,438 4,554 34 -603 -12 

California Coastal 4,447 3,775 85 3,913 3,193 82 -583 -15 

Atlantic and Gulf Coastal Plains 14,395 2,127 15 13,825 2,902 21 775 36 

Southwest 2,870 2,366 82 3,183 2,571 81 205 9 

Northern Plains 48,420 1,776 4 51,130 1,762 3 -14 -1 

South Central 6,135 930 15 5,107 672 13 -259 -28 

East Central 9,312 195 2 10,166 233 2 38 19 

Northeast 7,190 85 1 7,597 177 2 92 109 

* Regions in table sorted by declining CEAP II irrigated cropland acres. 
 

 

28 Conservation Effects Assessment Project 

Figure 15. Acres of Irrigation on Cropland and Pastureland, 2017 

Change in irrigated cropland between the CEAP surveys varied by region. There were increases 

in seven regions but declines in four—the Northern Plains, South Central, California Coastal, 

and Northwest. The greatest increase in irrigated cropland occurred in the Lower Mississippi and 

Texas Gulf Coast with over 2.6 million additional irrigated acres (fig. 16). Although the 

Northeast more than doubled irrigated acres between the CEAP surveys, it still has the fewest 

total irrigated acres (table 12, above). The Atlantic and Gulf Coastal Plains, North Central and 

Midwest, and Lower Mississippi and Texas Gulf Coast all increased irrigated area by 30 percent 

or more from CEAP I levels. 

Irrigation intensity is greatest in areas with low rainfall in the growing season, or where crops 

require either additional water or water at a different time than normal precipitation. Irrigation is 

employed on 82 percent of the cropland acres in the California Coastal region and on 81 percent 

in the Southwest region, both characterized by low rainfall. In the more humid Lower 

Mississippi and Texas Gulf Coast region, about 56 percent of the cropland is irrigated due to the 

crops grown (rice is 100-percent irrigated), low soil water holding capacity, and precipitation 

timing (table 12, above). 
 

 

 

 

Conservation Practices on Cultivated Cropland 29 

Figure 16. Change in Irrigated Cropland by Region, CEAP I to CEAP II 

Note: Number at the end of each bar reflects the percent change in irrigated acreage relative to CEAP I levels. 

Water Sources 

In CEAP II, about 77 percent of irrigated cropland acres were served by groundwater, 21 percent 

by surface water, and the remaining 2 percent by the combined sources (fig. 17). Use of 

groundwater increased by about 6 percent (over 6 million acres), and use of surface water and 

combined sources declined by 4 percent (more than 900,000 acres) and 1 percent (400,000 

acres), respectively, relative to CEAP I levels. While surface water sources are more susceptible 

to drought shortages, groundwater sources may be challenged by aquifer declines and exhaustion 

of the resource. 

Figure 17. Sources of Water for Irrigated Cropland, CEAP I and CEAP II 
30 Conservation Effects Assessment Project 

Surface water was the predominant irrigation water source in the western United States 

(California Coastal, Northwest, and Southwest regions) and the East Central region, while 

groundwater sources dominated in the remaining seven regions. However, groundwater is an 

important and growing share of irrigation water supplies in the western regions. In the Southwest 

region, groundwater-supplied acres increased by 20 percentage points (18 points from 

groundwater and 2 points from combined sources)—from 24 percent in CEAP I to 42 percent by 

CEAP II. In the Northwest region groundwater-supplied acres increased by 14 percentage points 

while surface water acres decreased by a similar share. The California Coastal region’s 

dependence on groundwater grew by 11 percentage points, while surface-only irrigated acres 

decreased by only 1 percentage point (fig. 18) 

Application Methods 

In the period between CEAP I and CEAP II there was a national shift toward irrigation pressure 

application systems, increasing 12 percentage points to 66 percent, and accounting for 8.7 

million acres. Most regions primarily use pressure systems, while three regions (California 

Coastal, South Central, and Lower Mississippi and Texas Gulf Coast) primarily use gravity 

application methods. The East Central and Northeast regions depend wholly on pressure-based 

systems (fig. 19). 

Between the two survey periods, every region except the South Central maintained or increased 

the share of irrigated cropland served by pressure systems. Use of pressure systems in the 

Atlantic and Gulf Coastal Plains region increased by 25 percentage points (1.3 million acres), in 

the Northwest and Southwest regions by 19 percentage points (over 400,000 and 500,000 acres, 

respectively), and in the California Coastal and Southern and Central Plains regions by 15 

percentage points (400,000 acres and 3.4 million acres, respectively). The South Central region’s 

decline in pressure systems was consistent with the overall irrigated cropland decline of 259,000 

acres in the region. 

Nationally, low-pressure center pivot systems were the most prevalent in CEAP I and CEAP II, 

and the share of irrigated cropland area served by these systems increased from 30 percent to 37 

percent (13.4 to 18.6 million acres) (fig. 20). Center pivot technology in its various forms (lowpressure spray, impact sprinklers, and on- or near-ground emitters) increased from 47 percent of 

irrigated cropland acres in CEAP I to 54 percent of cropland acres in CEAP II. The most used 

gravity irrigation technology was poly-pipe, which increased to 13 percent of cropped acres in 

CEAP II, up from 8 percent in CEAP I. Poly-pipe systems are extensively used in the Lower 

Mississippi and Texas Gulf Coast and South Central regions. The only other gravity distribution 

system with a double-digit share was an open discharge system from a well, pipeline, gate, or 

valve with 10 percent of acres in CEAP II, down from 12 percent in CEAP I. 

The regions that rely on pressure systems were increasingly using low-pressure spray center 

pivots (fig. 21). In the East Central region, the most common irrigation technology in CEAP II 

was hand-move sprinklers, which are not suitable for all crops. In the Northeast the most 

common irrigation technology in CEAP II was big gun sprinklers, which are relatively low-cost 

and are versatile across crops and terrain, but not as efficient as other pressure options. 
 

 

Conservation Practices on Cultivated Cropland 31 

Figure 18. Water Sources for Irrigated Cropland, Nationally and by Region, CEAP I and CEAP II 

Figure 19. Irrigation Water Application Technology, Nationally and by Region, CEAP I and CEAP II 
 

 

 

 

 

 

 

 

32 Conservation Effects Assessment Project 

Figure 20. National Irrigation Water Application Systems on Cropland, CEAP I and CEAP II 

* Low-Flow irrigation includes drip, trickle, and micro-sprinklers 

**Other pressure includes side roll or wheel move, solid or permanent and big gun each with less than 2 percent of acres. 

*** Open discharge is water flowing from a pipe, well, gate, or valve with no flow control. 

****Other gravity includes subirrigation, portal system from a lined ditch, and improved gated pipe (surge flow or cablegation) 

each with no more than 1 percent of acres. 

Figure 21. Most Prevalent Regional Irrigation Water Application Systems on Cropland, CEAP I and CEAP 

II 
 

 

 

 

 

Conservation Practices on Cultivated Cropland 33 

Application Efficiency 

Irrigation water efficiency is a measure of water inputs to production outputs and was estimated 

by calculating the Virtual Irrigation System Efficiency (VISE).24 The higher the VISE score, the 

more efficient the system. VISE is not a measured efficiency but is calculated from information 

obtained from a farmer survey on the physical distribution system, water source and conveyance 

method, and irrigator decisions on timing and amounts. Soil properties based on the field soil 

type from National Resources Inventory (NRI) points were also considered in the efficiency 

score. 

The average VISE score increased from 62 percent to 76 percent from CEAP I to CEAP II. The 

14-point (23-percent) improvement implies that irrigators needing to provide 12 inches of water 

to meet plant consumptive needs could reduce water application by 3.6 inches or almost 20 

percent. This potential reduction in water applied translates directly into reduced pumping costs 

for groundwater and reduced surface water diversions to maintain the same acreage. 

All regions increased their irrigation efficiencies between CEAP I and CEAP II (fig. 22). In 

CEAP II, the Southern and Central Plains and North Central and Midwest regions had the 

highest efficiency scores at 80 percent and the Northeast had the lowest at 70 percent. The 

Figure 22. VISE Efficiency Scores in CEAP I and CEAP II and Most Prevalent Technology in CEAP II, by 

Region 

24 Because the calculation process considers the delivery loss inherent in 19 water application technologies, runoff from the 

field (technology and management based) and deep percolation (soils, technology and management based), there can be a 

wide range of estimated VISE efficiency scores within an individual application technology as well as across technologies. 
 

 

34 Conservation Effects Assessment Project 

greatest gain in average score was in the East Central region from 55 percent in CEAP I to 77 

percent in CEAP II, in large part due to the shift to hand-move sprinklers. The smallest 

efficiency gains were the 8-percent increase in the Southern and Central Plains (low-pressure 

center pivot sprinklers in both periods) and the 10-percent increase in the Northeast (big gun 

sprinkler in both periods). The four regions with the highest estimated efficiency scores all relied 

on low-pressure center pivots as the most prevalent irrigation application technology. 

Nationally, there was about a 30-percent decline in acres with lower VISE scores and about a 40 

percent increase in acres with higher VISE scores. This pattern was repeated in all production 

regions (fig. 23). The shift may have been technology based or management based, or by adding 

irrigated acres on better suited soils, or more likely a combination of all efficiency drivers. 

Figure 23. Irrigated Acreage Distribution of VISE Efficiencies by VISE Grouping and Region, CEAP I and 

CEAP II 

Application Amount 

Total irrigation water applications on cropland declined nationally and in most regions despite 

the increase in irrigated acres. In CEAP I the average irrigation water application was 19.2 

inches per acre, declining to 15.6 inches per acre in CEAP II (table 13). Total irrigation water 

applications declined 10 percent (from 71.7 million acre-feet to 64.6 million acre-feet), even 

though irrigated acres increased by 11 percent (4.9 million acres). 

Nationally, the average per-acre decline in water application was about 3.6 inches with the 

Lower Mississippi and Texas Gulf Coast region having the greatest decline at 5.5 inches. Only 

one region, the Northeast, increased average water application per acre and total water applied 
 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 35 

from CEAP I to CEAP II; three regions (Southwest, North Central and Midwest, and Atlantic 

and Gulf Coastal Plains), despite having less water applied per acre, gained enough irrigated 

acres to increase total water applications as well. Two regions, Lower Mississippi and Texas 

Gulf Coast and Atlantic and Gulf Coastal Plains, recorded more than 20-percent declines in peracre water applications. In the South Central region, total water applications declined by over 30 

percent, due in large part to the nearly 30-percent decline in cultivated cropland acres. 

Table 13. Irrigation Water Applications, Total Water Applied, and Change in Water Applications, CEAP I to 

CEAP II, by Region 

Geographic Area 

CEAP I CEAP II Change CEAP I 

to CEAP II Change from CEAP I 

Average 

Water 

Applied 

Total 

Water 

Applied 

Average 

Water 

Applied 

Total 

Water 

Applied 

Average 

Water 

Applied 

Total 

Water 

Applied 

Average 

Water 

Applied 

Total 

Water 

Applied 

Inches/ 

acre 

1000 

acre-feet 

Inches/ 

acre 

1000 

acre-feet 

Inches/ 

acre 

1000 

acre-feet Percent Percent 

National 19.2 71,683 15.6 64,624 -3.6 -7,060 -19 -10 

Region* 

Southern & Central 

Plains 15.7 20,363 14 19,575 -1.7 -788 -11 -4 

Lower Mississippi & 

Texas Gulf Coast 23 17,193 17.5 16,991 -5.5 -202 -24 -2 

California Coastal 40.6 12,773 36.2 9,631 -4.4 -3,141 -11 -25 

Northwest 21.7 9,325 18.2 6,907 -3.5 -2,418 -16 -26 

Southwest 28 5,521 25.9 5,548 -2.1 28 -8 0 

North Central & 

Midwest 6.2 1,993 5.1 2,218 -1.1 225 -18 10 

Northern Plains 13 1,924 10.5 1,542 -2.5 -382 -19 -21 

South Central 20.5 1,589 19.5 1,091 -1 -498 -5 -31 

Atlantic & Gulf 

Coastal Plains 5.3 940 4.2 1,016 -1.1 76 -21 11 

East Central 4.4 72 3.7 72 -0.7 0 -16 0 

Northeast 2.9 20 3.5 52 0.6 31 21 900 

* Regions in table sorted by declining CEAP II total water application amounts. 

Nutrient Management 

Nitrogen is essential for protein formation, and plants take up more of this nutrient than any 

other. The second most required nutrient is phosphorus, essential for plants to use and store 

energy. Some crops, such as corn, have high nitrogen demands, while others such as soybeans 

meet their nitrogen demand through a process called biological nitrogen fixation. 

Practices to manage nutrients include application rate, timing, method, and form or source. There 

are many ways to combine these four components to maintain or enhance production and 

minimize potential losses. Climate, soil, cropping system, and tillage influence the options 

available to farmers (box 4). 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

36 Conservation Effects Assessment Project 

Box 4. Advances in Nutrient Technology 

Precision guidance systems allow for improved placement of nutrients and the ability to apply nutrients to actively growing 

crops. Together, variable-rate technologies in combination with enhanced-efficiency fertilizers (EEFs) can better match nutrient 

application rates to the differing needs of unique soil types within a field and their production potential, and reduce the impact 

of early application by extending the release of nutrients and, for some forms, by reducing volatile losses. 

Use of variable rate technology more than quadrupled between CEAP I and CEAP II. Gains were concentrated in the North 

Central and Midwest region, accounting for 55 percent of the total increase. Only two regions, South Central and Southwest, 

experienced small declines over the time period. 

Variable Rate Technology Adoption by Region, CEAP I and CEAP II 

Geographic Scope 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) 

Percent 

Acres 

Acres 

(1,000s) 

Percent 

Acres 

Acres 

(1,000s) 

Percent 

Acres 

National 12,567 4 51,215 16 38,648 12 

Region 

Atlantic and Gulf Coastal Plains 515 4 2,632 19 2,117 15 

California Coastal 192 5 296 8 104 3 

East Central 277 3 1,038 10 761 7 

Lower Mississippi and Texas Gulf Coast 493 3 3,885 19 3,392 16 

North Central and Midwest 6,023 5 27,632 22 21,610 17 

Northeast 160 2 426 6 266 3 

Northern Plains 1,849 4 7,575 15 5,726 11 

Northwest 1,022 8 2,302 17 1,280 10 

South Central 335 6 330 6 -5 1 

Southern and Central Plains 1,597 3 5,034 8 3,437 5 

Southwest 104 4 66 2 -38 -1 

Between the survey periods, use of EEFs increased by over 6-fold and were in use on over one-fourth of all cultivated cropland 

by CEAP II. All regions showed gains in EEF use, with the North Central and Midwest accounting for 55 percent of the total 

increase. 

Enhanced-Efficiency Fertilizer Adoption by Region, CEAP I and CEAP II 

Geographic Scope 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) 

Percent 

Acres 

Acres 

(1,000s) 

Percent 

Acres 

Acres 

(1,000s) 

Percent 

Acres 

National 11,734 4 74,146 26 64,412 22 

Region 

Atlantic and Gulf Coastal Plains 327 2 2,356 19 2,029 17 

California Coastal 130 4 352 10 222 7 

East Central 353 4 2,215 23 1,862 19 

Lower Mississippi and Texas Gulf Coast 983 6 4,629 28 3,646 23 

North Central and Midwest 8,301 7 44,139 38 35,838 31 

Northeast 353 5 2,754 39 2,401 34 

Northern Plains 355 1 8,334 17 7,978 16 

Northwest 154 1 1,871 15 1,717 13 

South Central 118 2 741 16 623 14 

Southern and Central Plains 642 1 6,505 12 5,863 11 

Southwest 17 1 249 9 232 8 
 

 

 

 

Conservation Practices on Cultivated Cropland 37 

Rate 

Nutrient application rates vary by crop and take into consideration all sources of essential 

nutrients. Cultivated cropland acres on which a soil test was taken within the last 5 years 

increased slightly over the decade, from 56 percent to 60 percent. Where manure was applied, 

soil testing rates were at 77 percent (box 5). However, nutrient application rates on manured 

acres still were substantially higher than rates on acres receiving only commercial fertilizers, 

perhaps related to a lag in manure testing. 

Nationally, application rates of nitrogen and phosphorus from all sources increased between the 

CEAP surveys (table 14). Average nitrogen rates increased by 7 percent, from 73 to 78.5 lbs/a/y. 

The largest increase occurred in the Northern Plains region at 16.6 lbs/a/y, over three times the 

national average increase. The North Central and Midwest was the only other region with a rate 

increase above the national average. The expansion of corn production in these two regions 

drove the need for more nitrogen (fig. 24). 

Phosphorus application rates increased by 15 percent, from 16.2 to 18.6 lbs/a/y. Five regions had 

rate increases above the national average increase of 2.4 lbs/a/y. The largest rate increase 

occurred in the Northern Plains region at 4.5 lbs/a/y. 

Table 14. Nutrients Applied on Cultivated Cropland, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

Nutrient Acres 

Receiving 

(1,000s) 

Tons 

Applied 

(1,000s) 

Rate 

(lbs/a/y) 

Acres 

Receiving 

(1,000s) 

Tons 

Applied 

(1,000s) 

Rate 

(lbs/a/y) 

Acres 

Receiving 

(1,000s) 

Tons 

Applied 

(1,000s) 

Rate 

(lbs/a/y) 

Nitrogen 294,384 11,433 73 294,069 12,263 78.5 -315 830 5.2 

Phosphorus 268,472 2,538 16.2 278,859 2,930 18.6 10,387 392 2.4 

Figure 24. Change in Nitrogen and Phosphorus Application Rates by Region, CEAP II minus CEAP I 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

38 Conservation Effects Assessment Project 

Box 5. Soil Testing for Nutrient Management 

Testing soils for nitrate nitrogen, phosphorus, organic matter, potassium, pH, and soluble salts content provides essential 

information for developing a sound nutrient management strategy and determining appropriate nutrient application rates to 

promote healthy plant growth and minimize potential for nutrient losses. Between the CEAP surveys, the share of cultivated 

cropland acres having had a soil test within the previous 5 years increased from 56 to 60 percent. 

Soil Testing on Cultivated Cropland, CEAP I and CEAP II 

Cultivated Cropland with Soil Test within 

Previous 5 Years by Nutrient Type 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) 

Acres 

Percent 

Acres 

(1,000s) 

Acres 

Percent 

Acres 

(1,000s) 

Acres 

Percent 

Cultivated Cropland Acres with Soil Test 174,086 56 189,222 60 15,136 4 

Commercial N and P and/or Manure 171,626 57 187,332 62 15,706 5 

Commercial N and P Only 154,143 56 163,679 60 9,536 4 

Manure with/without Commercial N and P 17,483 65 23,653 77 6,169 12 

No Commercial N or P Applied 2,460 20 1,890 14 -570 -5 

Cultivated cropland acres receiving manure (with or without commercial fertilizers) were tested more frequently than those 

receiving commercial fertilizers only. In CEAP II, 77 percent of manured acres had recent soil tests, compared to 60 percent of 

acres receiving commercial fertilizer only. 

Between CEAP I and CEAP II, soil testing rates on acres receiving only commercial fertilizer increased by 4 percentage points, 

from 56 percent in CEAP I to 60 percent in CEAP II. In contrast, soil testing on acres receiving manure increased by 12 

percentage points, suggesting growing awareness of the importance of soil testing when using manure nutrients. However, the 

use of manure testing to understand manure nutrient content lagged at only 48 percent in CEAP II. Consequently, over half the 

acres receiving manure lacked information to establish appropriate application rates to ensure meeting crop needs, while 

minimizing potential for losses or soil phosphorus accumulation. 

Most regions increased the number of cultivated cropland acres with recent soil tests in CEAP II. In the California Coastal, 

Northeast, and Northwest regions, soil testing increased by 13 percentage points or more. The South Central region was alone 

in experiencing a reduction in acres with a recent soil test. Six regions had soil testing rates higher than the national average (60 

percent). The South Central, Southern and Central Plains, Southwest, and Lower Mississippi and Texas Gulf Coast were the only 

regions with soil testing rates below 50 percent of their regional cultivated cropland acres. 

Soil Testing* on Cultivated Cropland by Region, CEAP I and CEAP II 

Geographic Scope 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) 

Acres 

Percent 

Acres 

(1,000s) 

Acres 

Percent 

Acres 

(1,000s) 

Acres 

Percent 

National 174,086 56 189,222 60 15,136 4 

Region 

Atlantic and Gulf Coastal Plains 11,262 78 10,793 78 -469 <1 

California Coastal 1,768 40 2,127 54 359 15 

East Central 5,698 61 6,258 62 560 0 

Lower Mississippi and Texas Gulf Coast 9,548 44 9,476 45 -71 2 

North Central and Midwest 78,583 65 85,025 69 6,442 4 

Northeast 4,097 57 5,308 70 1,211 13 

Northern Plains 26,106 54 31,276 61 5,170 7 

Northwest 7,748 55 9,636 72 1,888 16 

South Central 2,252 37 1,638 32 -614 -5 

Southern and Central Plains 26,052 40 26,353 42 301 2 

Southwest 972 34 1,332 42 360 8 

* Soil test within the previous 5 years 
 

 

 

Conservation Practices on Cultivated Cropland 39 

Method 

Nutrients are applied to fields in a variety of ways but can be divided between those that place 

the nutrient on the soil surface and those that incorporate nutrients beneath the soil surface. 

Knifing, injection, and other incorporation methods place nutrients in the root zone for growing 

plants, which also reduces potential for nutrient loss via wind and rain. There are many reasons 

that drive decisions on application method from the nutrient source (some manures are more 

difficult to incorporate) to application timing (incorporating nutrients into a growing crop is 

more difficult). 

Between the two CEAP surveys, there was a clear trend away from nutrient incorporation on 

cultivated cropland, and as a result increased opportunity for losses from fields. By CEAP II, 50 

percent of nitrogen applied and 20 percent of phosphorus applied were not incorporated (table 

15; appendix 2, tables A-10 and A-11). The acreage on which all nutrient applications were 

incorporated declined for nitrogen (by 29 percent) and phosphorus (by 24 percent). In contrast, 

the acres where none of the nutrient applications were incorporated increased for nitrogen (by 41 

percent) and phosphorus (by 46 percent). 

All regions experienced a similar pattern of a decrease in all applications incorporated and an 

increase in applications with no incorporation for both nutrients (fig. 25). Three regions—North 

Central and Midwest, Northern Plains, and Southern and Central Plains—accounted for 90 

percent of the change in tons of nitrogen applied without incorporation. The North Central and 

Midwest region alone accounted for nearly half of the change in tons of phosphorus applied 

without incorporation. 

Table 15. Cultivated Cropland with Nutrients Applied by Type and Incorporation, CEAP I and CEAP II 

Incorporation Status 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) Percent Tons (1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Acres (1,000s) 

Percent 

Relative 

to 

CEAP I 

Tons 

(1,000s) 

Percent 

Relative 

to 

CEAP I 

Nitrogen 

Application Acres 294,384 11,433 294,069 12,263 -315 830 7 

All Incorporated 152,265 52 5,275 46 107,423 37 3,864 32 -44,842 -29 -1,411 -27 

Some Incorporated 101,346 34 1,513 13 129,018 44 2,223 18 27,672 27 710 47 

None Incorporated 40,773 14 4,645 41 57,628 20 6,176 50 16,855 41 1,531 33 

Phosphorus 

Application Acres 268,472 2,538 278,859 2,930 10,387 4 393 15 

All Incorporated 133,376 50 1,116 44 100,995 36 923 32 -32,381 -24 -193 -17 

Some Incorporated 99,392 37 1,070 42 125,593 45 1,418 48 26,201 26 348 33 

None Incorporated 35,704 13 352 14 52,270 19 589 20 16,567 46 237 67 

Timing 

Nutrients may be applied before planting (pre-plant), at the time of planting (at-plant), or 

following the emergence of the crop (post-plant). In general, nutrient uptake rates are highest 

from early to mid-growing season, which is why at-plant and post-plant applications together 

account for the largest share of applications. Post-plant applications occur when crops are 

actively growing and have the greatest nutrient needs; however, incorporation is complicated by 

the potential for plant damage. Pre-plant application avoids the challenge of applying fertilizer, 

particularly manure, to a growing crop, but leaves nutrients exposed for a longer time before 

uptake, increasing opportunities for losses. 
 

 

40 Conservation Effects Assessment Project 

Figure 25. Change in Incorporation Extent and Region, CEAP II minus CEAP I 

Pre-plant (>21 days) applications that were not incorporated increased while incorporated 

applications declined. By CEAP II, the increases in the unincorporated pre-plant load were 

392,000 tons for nitrogen and 95,000 tons for phosphorus, while incorporated loads dropped by 

172,000 tons for nitrogen and 46,000 tons for phosphorus. 

Most nitrogen and phosphorus applications are at plant (application within 7 days of planting), 

although there was a net decline in tons applied between the two CEAP surveys. Nitrogen 

applied at plant and incorporated declined by 22 percent, while applications not incorporated 

increased by 28 percent relative to CEAP I levels. Phosphorus applied at plant and incorporated 

declined by 7 percent, and applications not incorporated increased by 22 percent relative to 

CEAP I levels (fig. 26; appendix 2, tables A-12 and A-13). 

The nutrients applied during the other three timing periods increased by nearly 1.5 million tons 

of nitrogen and 372,000 tons of phosphorus. Most of the increase occurred post-plant and as 

unincorporated applications of nitrogen and phosphorus, 61-percent and 169-percent increases 

from CEAP I levels, respectively. 
 

 

 

 

 

Conservation Practices on Cultivated Cropland 41 

Figure 26. Total Applied Nutrients by Timing and Incorporation, CEAP I and CEAP II 

Note: The increase in the unincorporated load relative to CEAP I levels is shown as a percent above the CEAP II values for each 

application timing. 

Technology advances, such as nitrogen inhibitors and precision guidance systems, increase 

timing options; despite this, incorporation is still essential to reduce loss risk. Between the CEAP 

survey periods, enhanced-efficiency fertilizers were used on an additional 64 million acres by 

CEAP II or 26 percent of cultivated cropland (see also box 4, page 36). Farmers also increased 

the use of variable rate technology (VRT), using it on an additional 38.6 million acres or 17 

percent of all cultivated cropland by CEAP II. 

Manure Application Trends 

Between CEAP I and CEAP II, acres receiving manure nutrients increased substantially, 

reflecting the continuing increase and consolidation in the sector. The significant increase in the 

purchase of manure nutrients signaled a departure from viewing manure simply as a wastedisposal problem. While soil testing increased and manured acres had substantially higher testing 

rates, increased application rates and load-to-loss disparities indicate continuing challenges. 

Manure nutrients can be more mobile than commercial mineral nutrients as they may be less 

dense and more soluble, although the fraction of manure nutrients in organic form may release 
 

 

 

 

 

 

 

 

 

42 Conservation Effects Assessment Project 

over time through mineralization. A combination of proper rates, timing, and application 

methods is necessary to manage losses from all sources to meet defined threshold levels. 

Cultivated cropland receiving manure increased by 14 percent to nearly 31 million acres in 

CEAP II, roughly 10 percent of all cultivated cropland (table 16). Between CEAP I and CEAP II, 

acres receiving only manure nutrients increased by 28 percent (908,000 acres) and acres 

receiving manure and commercial fertilizer increased by 12 percent (2.8 million acres). In both 

surveys, acres receiving manure had higher nitrogen and phosphorus application rates than those 

receiving only commercial fertilizer—over 71 and 90 percent higher, respectively, in CEAP II. 

Table 16. Average Annual Nutrient Application Rates—Manured and Commercial Only 

Nutrient Source 

Cultivated Cropland Nitrogen Application Rate Phosphorus Application Rate 

CEAP I CEAP II 

CEAP II 

minus 

CEAP I 

CEAP I CEAP II 

CEAP II 

minus 

CEAP I 

CEAP I CEAP II 

CEAP II 

minus 

CEAP I 

Acres (1,000s) Pounds/acre/year 

Manure Acres 

(with or without 

Commercial) 

27,013 30,727 3,713 136 140 5 39 38 -1 

Manure Only 

Acres 3,241 4,150 908 112 110 -2 42 40 -2 

Manure w/ 

Commercial 23,772 26,577 2,805 139 145 5 39 38 -1 

Commercial 

Nitrogen without 

Manure 

267,371 263,343 -4,028 76 82 6 

Commercial 

Phosphorus 

without Manure 

241,459 248,132 6,673 18 20 2 

The top three regions for receiving manure were the North Central and Midwest at 16.3 million 

acres, the Southern and Central Plains with 3.2 million acres, and the Northeast with 3.1 million 

acres. While manured acres are a minor portion of the total acres in the North Central and 

Midwest (13 percent) and Southern and Central Plains (5 percent) regions, they make up 41 

percent of the cultivated cropland acres in the Northeast. 

Because of higher application rates, manured acres received a disproportionate share of the total 

nutrients applied in every region (fig. 27). Overall, the proportion of nitrogen losses equaled or 

were below the applied load in 10 regions, while for phosphorus losses that was the case in only 

five regions. In the North Central and Midwest region, the 13 percent of regional acres that 

received manure accounted for 19 percent of the total applied nitrogen and 20 percent of the total 

applied phosphorus, while nitrogen and phosphorus losses on these acres were 19 percent and 36 

percent of the total regional losses, respectively. In the Northeast, the 41 percent of acres that 

received manure accounted for 59 percent of total applied nitrogen and 62 percent of the total 

applied phosphorus. While nitrogen losses were less than the applied load, they still made up 

nearly half (47 percent) of the regional nitrogen losses; phosphorus losses at 68 percent exceed 

the applied phosphorus load, making manure management one of the highest regional priorities. 

The contrast in percent load and percent loss illustrates the regional challenges in managing 

manure nutrients, particularly with respect to its commercial counterpart. 
 

 

 

 

Conservation Practices on Cultivated Cropland 43 

Figure 27. Nitrogen and Phosphorus Applied Load and Losses from Cultivated Cropland Receiving Manure 

Nutrients, CEAP II 

Acres receiving manure and commercial fertilizer have nutrient application rates nearly twice 

that of acres receiving only commercial fertilizers, and almost a third higher than acres receiving 

manure alone. In seven regions, commercial nitrogen accounts for 40 percent or more of the total 

nitrogen applied on manured acres (fig. 28). Overall phosphorus application rates are lower, but 

commercial phosphorus still accounts for 20 percent or more of the total phosphorus applied in 

six regions. The use of manure testing to understand nutrient content was done on only 48 

percent of the manured cropland in CEAP II; consequently, over half the acres receiving manure 

lacked adequate information to establish appropriate application rates for crop needs, while 

minimizing potential for losses or soil phosphorus accumulation. It is unclear why operators may 

apply additional commercial fertilizer, which may not be necessary for crop production, 

constitutes an additional production cost, and may increase potential loss risks. This suggests 

there is a need to better understand manure nutrient content and availability for plant growth. 

Between the CEAP surveys, winter application of manure declined, largely the portion that was 

not incorporated, and reduced the amount of manure nutrients exposed to potential losses in that 

season. Applications in the other three seasons—but particularly in spring and fall—increased 

(fig. 29). Most of the total load is applied in spring and fall before and after the active growing 

periods of most crops, when incorporation is critical to ensure that applied nutrients remain in 

place. 
 

 

 

44 Conservation Effects Assessment Project 

Figure 28. Nitrogen and Phosphorus Applied to Manured Acres by Source and Region, CEAP II 

Figure 29. Seasonal Application of Manure Nutrients by Method, CEAP I and CEAP II 
 

 

 

 

 

Conservation Practices on Cultivated Cropland 45 

Spring is generally the wettest season, increasing the potential for nutrient losses. The total 

spring load increased by 12 percent for nitrogen and 18 percent for phosphorus, and while the 

incorporated applications increased, led by increases in dairy and swine manure injection, so also 

did applications that were not incorporated. Fall applications also increased as did the 

incorporated portion, particularly for nitrogen. 

While the summer load and its unincorporated portion increased, applications are on actively 

growing crops, which have lower loss potential even when broadcast without incorporation. U.S. 

poultry production expanded over the 2011–20 period, as producers sought to meet increased 

demand.25 The increased use of poultry manure (a solid form) with limited incorporation options 

may explain some of the notable increase in unincorporated manure. 

There was a significant change in the marketing and acceptance of manure as a nutrient source 

between the CEAP survey periods, suggesting continuing opportunities for improving the use of 

the resource. The most notable shift was the nearly threefold increase in acres applying 

purchased manure. While manure applied on operations where it was produced still accounted 

for most manured acres, that segment declined by 13 percent (2.5 million acres). Acres on which 

users were compensated to receive and apply manure increased by nearly 900,000 acres (131 

percent), indicating that livestock producers continue to seek ways to get manure on more acres 

(table 17). 

Table 17. Cultivated Cropland with Manure Applied, by Source, CEAP I and CEAP II 

Source of Manure CEAP I CEAP II CEAP II -

CEAP I 

Percent 

Change 

Relative to 

CEAP I 

Acres (1,000s) 

On Operation 19,350 16,889 -2,460 -13 

Off Operation 7,664 13,837 6,173 81 

No Cost 4,453 2,759 -1,694 -38 

Compensated 676 1,564 888 131 

Purchased 2,535 9,514 6,979 275 

Total 27,013 30,727 3,713 14 

25 https://www.ers.usda.gov/topics/animal-products/poultry-eggs/sector-at-a-glance/ 
 

 

 

 

 

 

46 Conservation Effects Assessment Project 

HOW DID CONSERVATION ADOPTION AFFECT RESOURCE 

CONCERNS? 

Between the CEAP surveys, adoption of soil-conserving practices had a positive effect on 

multiple cultivated cropland conditions—reducing erosion, increasing soil carbon, reducing 

losses of sediment, and restricting some nutrient loss pathways. Loss thresholds were established 

for each of these resource concerns to present an estimated conservation condition, assess 

potential treatment needs, and provide context for potential future loss reductions.26 The 

thresholds do not reflect or suggest conservation-related policy standards, and do not indicate 

that any specific natural resource targets would be achieved if thresholds were met (e.g., water 

quality standards). Meeting a threshold is not a static condition, as cultivated cropland may 

experience periodic losses above or below a threshold under extreme conditions, such as 

prolonged intense rainfall or drought. 

Cultivated cropland meeting loss thresholds for erosion, sediment, surface nitrogen, and 

sediment-transported phosphorus increased or remained stable, but declined for subsurface 

nitrogen and soluble phosphorus between CEAP I and CEAP II. In both surveys, most of the 

sediment, nitrogen, and phosphorus losses came from a small number of cultivated cropland 

acres that exceeded specific loss thresholds. CEAP provides estimates of edge-of-field losses 

through surface and subsurface pathways;27 however, the estimates do not suggest a particular 

fate of transported materials (e.g., to water) or potential impact. 

Erosion 

Controlling soil erosion from water and wind is essential to maintaining soil health and 

productivity and has been a longstanding conservation objective. Too much erosion on farm 

fields creates challenges for sustaining soil productivity, while windborne soil or sediment 

leaving a field can generate negative offsite impacts. Forms of water erosion on farm fields 

include sheet and rill, ephemeral gully, and classic gully. Sheet and rill erosion is generally a 

resource concern in higher rainfall areas and on steeper slopes. Wind erosion is primarily a 

resource concern in arid and semiarid regions, although it can also be a problem in wetter regions 

or on certain organic soils. Conservation practices such as conservation tillage, conservation crop 

rotations, cover crops, and structural practices all help control erosion. In regions with low 

rainfall, vegetative structural wind erosion control practices are constrained as they compete with 

crops for limited water supplies. 

The concept of soil loss tolerance is used to aid in understanding the potential effects of soil 

erosion on soil productivity. The soil loss tolerance rate—“T”—reflects the estimate of annual 

soil loss that can occur and still permit crop productivity to be sustained economically and 

indefinitely on a given soil. The T value varies by soil, with deeper, uniform soils having higher 

26 Threshold levels were derived through a series of forums with technical experts and refined by further 

examination of model output to establish thresholds that were agronomically feasible and could be achieved with 

existing production and conservation technology. Criteria used to establish these thresholds were refined for CEAP 

II, so the CEAP I findings reported here will differ from those found in previous CEAP I reports. 

27 Subsurface loss estimates include natural lateral drainage, deep drainage, and tile and ditch drains. 
 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 47 

T values than shallow or previously eroded soils. Examining erosion levels relative to their T 

value provides one way to assess whether fields are stable or declining. 

Sheet and Rill Erosion 

Between CEAP I and CEAP II, average annual sheet and rill erosion on cultivated cropland 

dropped by over 76 million tons per year, a 13-percent reduction relative to CEAP I (table 18). 

Rates declined from 1.9 tons per acre per year (t/a/y) to 1.7 tons t/a/y over the decade. 

In CEAP I and CEAP II, most cultivated cropland acres met the threshold (soil T) at 89 percent 

and 90 percent, respectively. As a result of the increase in conservation tillage and structural 

practices, cultivated cropland meeting the threshold increased by over 6.5 million acres and 

cultivated cropland exceeding the threshold dropped by 4.3 million acres, 12 percent from CEAP 

I levels (table 18; appendix 2, table A-14). 

Total sheet and rill erosion on cultivated cropland meeting the threshold dropped by 30.6 million 

tons, an 11-percent reduction from CEAP I levels. Erosion on acres exceeding T dropped by 45.8 

million tons, a 14-percent reduction from CEAP I levels. Most erosion continued to come from 

the acres exceeding T; 55 percent of total sheet and rill erosion in both surveys came from 

cultivated cropland eroding at rates above T although these acres accounted for only 11 and 10 

percent of acres in CEAP I and CEAP II, respectively. 

Table 18. Sheet and Rill Erosion by Threshold, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) Percent Tons (1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Acres (1,000s) 

Percent 

Relative 

to CEAP I 

Tons 

(1,000s) 

Percent 

Relative to 

CEAP I 

Total 313,065 100 598,623 100 315,303 100 522,263 100 2,238 1 -76,360 -13 

Meeting 

Threshold 277,546 89 266,834 45 284,132 90 236,252 45 6,586 2 -30,583 -11 

Exceeding 

Threshold 35,519 11 331,789 55 31,171 10 286,012 55 -4,348 -12 -45,777 -14 

The North Central and Midwest region, with nearly 40 percent of all cultivated cropland, 

accounted for over 50 percent of the total sheet and rill erosion in CEAP II. The East Central, 

Lower Mississippi and Texas Gulf Coast, and Southern and Central Plains had the next highest 

loads, and together accounted for 28 percent of total sheet and rill erosion (fig. 30). 

Between the surveys, the national average sheet and rill erosion rate on all cultivated cropland 

dropped by 0.2 t/a/y. The Northeast region experienced the largest reduction at 1 t/a/y, and rate 

reductions in the North Central and Midwest and Southern and Central Plains regions were the 

same as the national average. The East Central and South Central regions with their generally 

sloping landscapes and humid, high rainfall climate had the highest average sheet and rill erosion 

rates in CEAP II at 4.1 t/a/y. 

Rainfall and inherent soil runoff vulnerability are the primary forces driving sheet and rill 

erosion on cultivated cropland (box 6, page 50). Over 77 percent of the cultivated cropland with 

sheet and rill erosion exceeding the threshold receives average annual rainfall of 35 inches or 

more, and most of those acres have moderately high or high vulnerability to runoff (table 19). 
 

 

48 Conservation Effects Assessment Project 

Figure 30. Sheet and Rill Erosion on Cultivated Cropland Relative to Threshold, CEAP I and CEAP II 
 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 49 

Table 19. Cultivated Cropland with Sheet and Rill Erosion above T by Soil Vulnerability Runoff and 

Rainfall, CEAP II 

SVI Runoff 

Rating 

Average Annual Rainfall 

< 15 inches > 15 and < 25 inches > 25 and < 35 inches > 35 and < 45 inches > 45 inches 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Low 0 - 0 - 465 1 474 1 2,283 9 

Moderate 0 - 192 2 328 5 1,011 9 1,757 12 

Moderately 

High 0 - 374 4 2,492 17 5,472 31 4,027 46 

High 0 - 536 11 2,717 28 6,221 48 2,823 71 

National 0 - 1,101 1 6,002 8 13,178 16 10,890 21 

Between the CEAP surveys, cultivated cropland exceeding the sheet and rill threshold decreased 

overall and in all vulnerability categories (fig. 31). However, most acres exceeding the threshold 

remained in the high and moderately high vulnerability categories; 79 percent in CEAP II. While 

most regions experienced a decline in high vulnerability acres exceeding the threshold, the South 

Central and East Central regions experienced an increase. In three regions (East Central, 

Northeast, and South Central), more than 20 percent of the regional cultivated cropland acres 

exceed the sheet and rill threshold due to a mix of factors related to topography, annual rainfall, 

and cropping systems. 

Figure 31. Cultivated Cropland Exceeding Sheet and Rill Erosion Threshold by SVI-R and CEAP Survey 

Wind Erosion 

Between the two CEAP surveys, wind erosion dropped by nearly 94 million tons per year by 

CEAP II, a 16-percent reduction relative to CEAP I. Rates dropped from an annual average of 

1.9 t/a/y to 1.6 t/a/y. 

Most cultivated cropland acres met the wind erosion threshold (soil T) at 88 percent in CEAP I 

and 90 percent in CEAP II. Cultivated cropland meeting the wind erosion threshold increased by 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

50 Conservation Effects Assessment Project 

Box 6. Controlling Erosion on Highly Erodible Land (HEL) 

Between the CEAP surveys, major gains were made in controlling erosion on highly erodible land (HEL) cropland. Gains in 

conservation tillage and structural practices on HEL helped to reduce losses, despite the overall increase in cultivation of HELdesignated cropland. 

Sheet and rill erosion on HEL was reduced by over 39 million tons, 52 percent of the total sheet and rill erosion reduction 

despite an increase in cultivation of 4.3 million acres. The average sheet and rill erosion rate on HEL dropped from 6.8 t/a/y to 

5.1 t/a/y. Despite these gains, in CEAP II, HEL acres still accounted for 40 percent of total sheet and rill erosion while accounting 

for only 13 percent of the acres. 

Of the 41 million acres designated HEL for sheet and rill erosion in CEAP II, 40 percent were eroding above the tolerance rate 

(T), down from 55 percent in CEAP I. The North Central and Midwest region alone accounted for 63 percent of HEL acres 

eroding above T and 63 percent of the load from HEL. In CEAP II, four regions (Lower Mississippi and Texas Gulf, East Central, 

Atlantic and Gulf Coastal Plains, and South Central regions) had over 50 percent of their respective regional HEL acres eroding 

above T; these regions have high concentrations of low-residue crops (e.g., cotton and soybeans) and higher rainfall. Average 

soil slopes on HEL cropland in the East Central region are among the highest of all regions. 

Highly Erodible Cultivated Cropland Vulnerable to Sheet and Rill Erosion, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

HEL NHEL Total HEL NHEL Total HEL NHEL Total 

Acres (1,000s) 37,017 276,048 313,065 41,392 273,911 315,303 4,375 -2,137 2,238 

Tons (1,000s) 250,734 347,889 598,623 211,319 310,944 522,263 -39,415 -36,945 -76,360 

Rate (t/a/y) 6.8 1.3 1.9 5.1 1.1 1.7 -1.7 -0.1 -0.3 

Percent Cultivated 

Cropland Acres 12 88 13 87 1.3 -1.3 

Percent Tons Erosion 42 58 40 60 -1.4 1.4 

Losses on highly erodible land (HEL) cropland susceptible to wind erosion were reduced by nearly 22 million tons by CEAP II, 

despite a 2.7-million-acre increase in cultivated acreage. The average wind erosion rate on HEL dropped from 5.3 t/a/y to 4.5 

t/a/y. More remains to be done; although HEL cultivated cropland accounted for 14 percent of the acres, it generated 41 

percent of wind erosion in CEAP II. 

Of the 45.7 million acres designated HEL for wind erosion in CEAP II, 27 percent were eroding above the tolerance rate (T), 

down from 37 percent in CEAP I. The Southern and Central Plains region alone accounted for 68 percent of HEL acres eroding 

above T and 79 percent of the load from HEL. In CEAP II, two of the regions that are most susceptible to wind erosion (Southern 

and Central Plains and Southwest regions) had over a third of their respective regional HEL acres eroding above T. 

Highly Erodible Cultivated Cropland Vulnerable to Wind Erosion, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

HEL NHEL Total HEL NHEL Total HEL NHEL Total 

Acres (1,000s) 42,908 270,156 313,065 45,665 269,638 315,303 2,757 -518 2,238 

Tons (1,000s) 228,677 374,928 603,605 206,914 302,826 509,740 -21,763 -72,102 -93,865 

Rate (t/a/y) 5.3 1.4 1.9 4.5 1.1 1.6 -0.8 -0.3 -0.3 

Percent Cultivated 

Cropland Acres 14 86 14 86 0.8 -0.8 

Percent Tons Erosion 38 62 41 59 2.7 -2.7 
 

 

 

 

Conservation Practices on Cultivated Cropland 51 

nearly 10 million acres between the surveys, while acres exceeding the threshold dropped by 7.6 

million acres, 20 percent from CEAP I levels (table 20; appendix 2, table A-15). 

Table 20. Wind Erosion by Threshold, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) Percent Tons (1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Acres (1,000s) 

Percent 

Relative 

to CEAP I 

Tons 

(1,000s) 

Percent 

Relative to 

CEAP I 

Total 313,065 100 603,605 100 315,303 100 509,740 100 2,238 1 -93,865 -16 

Meeting 

Threshold 274,431 88 258,919 43 284,309 90 197,904 39 9,878 4 -61,015 -24 

Exceeding 

Threshold 38,634 12 344,686 57 30,994 10 311,836 61 -7,640 -20 -32,850 -10 

Most of the total reduction in tons of wind erosion on cultivated cropland came from acres 

meeting the threshold, which dropped by 61 million tons, or 65 percent of the total. Wind erosion 

from cultivated cropland exceeding the threshold dropped by 32.8 million tons (35 percent of the 

total). By CEAP II, cultivated cropland with wind erosion exceeding the threshold accounted for 

only 10 percent of acres in CEAP II, but generated 61 percent of the total wind erosion load (fig. 

32). 

The primary regions with wind erosion concerns are the Northern Plains, Northwest, Southern 

and Central Plains, and Southwest. Of these, the Northern Plains and Southern and Central Plains 

regions account for 36 percent of total cultivated cropland acres but 77 percent of total wind 

erosion in CEAP II. 

Between the surveys, the national average wind erosion rate on all cultivated cropland dropped 

by 0.3 t/a/y. The Southwest region experienced the largest reduction at 2.4 t/a/y, and rate 

reductions in the Northwest and Southern and Central Plains regions were greater than the 

national average, at 0.8 and 0.7 t/a/y, respectively. Despite declines, the Northern Plains, 

Northwest, Southern and Central Plains, and Southwest still had the highest average wind 

erosion rates in CEAP II. 

Inherent wind vulnerability and arid/semiarid conditions are the primary forces driving wind 

erosion on cultivated cropland. Nearly 81 percent of the cultivated cropland with wind erosion 

exceeding the threshold receives less than 25 inches of rainfall annually, and most of those acres 

have moderately high or high wind vulnerability (table 21). 

Between the CEAP surveys, cultivated cropland exceeding the wind threshold decreased overall 

and in all vulnerability categories (fig. 33). However, most exceeding acres remained in the 

moderately high and moderate vulnerability categories; 84 percent in CEAP II. While most 

regions experienced a decline in moderately high vulnerability acres exceeding the threshold, the 

Northern Plains and North Central and Midwest regions experienced an increase. In three regions 

(Northern Plains, Southern and Central Plains, and Southwest), more than 20 percent of the 

regional cultivated cropland acres exceeded the wind threshold due to a mix of factors related to 

climate and cropping systems. 
 

 

52 Conservation Effects Assessment Project 

Figure 32. Wind Erosion on Cultivated Cropland Relative to Threshold, CEAP I and CEAP II 
 

 

 

 

Conservation Practices on Cultivated Cropland 53 

Table 21. Cultivated Cropland with Wind Erosion above T by Soil Vulnerability Wind and Rainfall, CEAP II 

SVI Wind 

Rating 

Average Annual Rainfall 

< 15 inches > 15 and < 25 inches > 25 and < 35 inches > 35 and < 45 inches > 45 inches 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Low 0 0 0 0 1,721 3 632 1 59 0 

Moderate 24 7 8,915 17 1,303 11 0 - 0 -

Moderately 

High 3,797 17 10,708 39 2,155 41 0 - 0 -

High 276 39 1,366 54 37 19 0 - 0 -

National 4,097 18 20,989 25 5,217 7 632 1 59 0 

Figure 33. Cultivated Cropland Exceeding Wind Erosion Threshold by SVI-W and CEAP Survey 

Sediment 

Between CEAP I and CEAP II, total sediment losses dropped by 74 million tons (22 percent), as 

farmers applied conservation measures on cultivated cropland and moved acres to higher 

sediment management levels. Three regions (North Central and Midwest, Lower Mississippi and 

Texas Gulf Coast, and Southern and Central Plains) accounted for 77 percent of the total 

reduction. However, these three regions plus the East Central still accounted for 76 percent of the 

total sediment load in CEAP II (fig. 34). 

Average sediment loss on cultivated cropland dropped from 1.1 tons per acre per year to 0.9 

t/a/y. The Northeast region experienced the largest reduction at 0.7 t/a/y, and rate reductions in 

the Lower Mississippi and Texas Gulf Coast and North Central and Midwest regions also 

exceeded the national average. The East Central and South Central regions—with their generally 

sloping landscapes and humid, high rainfall climate—had the highest average sediment loss rates 

in CEAP II at 2.4 and 2.6 t/a/y, respectively. 

In both surveys, most cultivated cropland acres met the sediment threshold (2 t/a/y)—88 percent 

in CEAP I and 91 percent in CEAP II (table 22). As cultivated cropland meeting the threshold 

increased by 11 million acres over the decade, sediment loss on these acres declined by nearly 

12.7 million tons. 
 

 

 

54 Conservation Effects Assessment Project 

Figure 34. Cultivated Cropland and Sediment Load Relative to Sediment Threshold (Acres and Tons), CEAP 

I and CEAP II 
 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 55 

Cultivated cropland exceeding the sediment threshold dropped by nearly 9 million acres, from 12 

percent to 9 percent between CEAP I and CEAP II. The associated sediment load declined by 

61.5 million tons, or 83 percent of the total reduction. However, cultivated cropland exceeding 

the sediment threshold remains the largest source, with 9 percent of the acres delivering 68 

percent of the total sediment load in CEAP II (table 22; appendix 2, table A-16). 

Table 22. Sediment Loss by Threshold, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) Percent Tons (1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Acres (1,000s) 

Percent 

Relative 

to 

CEAP I 

Tons 

(1,000s) 

Percent 

Relative 

to 

CEAP I 

Total 313,065 100 337,635 100 315,303 100 263,455 100 2,238 1 -74,181 -22 

Meeting 

Threshold 274,952 88 95,946 28 285,968 91 83,218 32 11,016 4 -12,728 -13 

Exceeding 

Threshold 38,113 12 241,689 72 29,335 9 180,237 68 -8,778 -23 -61,452 -25 

By CEAP II, three regions (North Central and Midwest, East Central, and Lower Mississippi and Texas 

Gulf Coast) accounted for 74 percent of the total acres exceeding the sediment threshold and 73 percent 

of the associated sediment losses. 

Rainfall and inherent soil runoff vulnerability are the primary forces driving sediment loss from 

cultivated cropland (see also box 3, page 18). Of the 29.3 million cultivated cropland acres 

exceeding the sediment threshold in CEAP II, 22.2 million (76 percent) were in areas with more 

than 35 inches of annual rainfall, and 15.2 million acres (69 percent) had moderately high and 

high runoff vulnerability (table 23). Of all cultivated cropland acres with high runoff 

vulnerability and more than 45 inches of rain annually (3.9 million acres), 65 percent (2.5 million 

acres) exceeded the sediment loss threshold. 

Table 23. Cultivated Cropland Exceeding the Sediment Threshold by Soil Vulnerability Index Runoff and 

Rainfall, CEAP II 

SVI Runoff 

Rating 

Average Annual Rainfall 

< 15 inches > 15 and < 25 

inches 

> 25 and < 35 

inches 

> 35 and < 45 

inches > 45 inches 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Low 11 0 124 0 344 1 407 1 3,181 13 

Moderate 60 2 152 2 296 4 913 8 2,487 17 

Moderately 

High 36 0 201 2 2,498 17 3,749 22 3,401 39 

High 21 1 785 16 2,595 27 5,507 42 2,566 65 

National 128 1 1,262 2 5,733 8 10,576 13 11,636 22 

Between the CEAP surveys, cultivated cropland exceeding the sediment loss threshold decreased 

overall and in all vulnerability categories (fig. 35). However, most acres exceeding the threshold 

remained in the high and moderately high vulnerability categories; 73 percent in CEAP II. All 

regions experienced a decline in moderately high vulnerability acres exceeding the threshold, 

while only five regions experienced declines in all vulnerability categories (North Central and 

Midwest, Northern Plains, Northeast, Northwest, and Southern and Central Plains). Four regions 

(East Central, Lower Mississippi and Texas Gulf Coast, Northeast, and South Central) had more 

than 20 percent of their regional cultivated cropland acres exceed the sediment threshold due to a 

mix of factors related to climate and cropping systems. 
 

 

 

56 

II 

Conservation Effects Assessment Project 

Figure 35. Cultivated Cropland Exceeding the Sediment Threshold by Region and SVI-R, CEAP I and CEAP 

Surface Nitrogen 

Surface losses of nitrogen declined slightly between CEAP I and CEAP II, with only 11 percent 

of cultivated cropland acres exceeding the threshold of 15 pounds per acre per year (lbs/a/y) in 

both surveys (table 24; appendix 2, table A-17). In CEAP II, the 11 percent of acres exceeding 

the threshold generated 48 percent of the total surface nitrogen loss. The majority (65 percent) of 

the acres meeting the surface loss threshold were losing less than 5 lbs/a/y, helping to offset the 

per-acre increase in losses on acres exceeding the threshold and resulting in the net reduction in 

surface nitrogen loss. 

Table 24. Surface Nitrogen Loss by Threshold, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) Percent Tons (1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Acres (1,000s) 

Percent 

Relative 

to 

CEAP I 

Tons 

(1,000s) 

Percent 

Relative 

to 

CEAP I 

Total 313,065 100 1,073 100 315,303 100 1,038 100 2,238 1 -35 -3 

Meeting 

Threshold 277,981 89 621 58 281,357 89 541 52 3,376 1 -80 -13 

Exceeding 

Threshold 35,084 11 452 42 33,946 11 497 48 -1,138 -3 45 10 

While most regions experienced a decline in cultivated cropland exceeding the surface loss 

threshold, the Northern Plains experienced an increase of more than 2.8 million such acres. Two 

regions (North Central and Midwest and Southern and Central Plains) accounted for a 4-millionacre decline in cultivated cropland exceeding the surface nitrogen loss threshold (fig. 36). 

Rainfall and inherent soil runoff vulnerability are the primary forces driving surface nitrogen loss 

from cultivated cropland. Of the 33.9 million cultivated cropland acres exceeding the surface 

nitrogen loss threshold in CEAP II, most were in areas receiving between 15 and 25 inches of 

rainfall annually (table 25). Some 18.8 million (55 percent) were in areas receiving more than 25 

inches of rainfall, down from 62 percent in CEAP I, while cultivated cropland receiving less than 
 

 

Conservation Practices on Cultivated Cropland 57 

Figure 36. Cultivated Cropland Relative to Surface Nitrogen Loss Threshold (Acres and Tons), CEAP I and 

CEAP II 
 

 

 

 

 

 

58 Conservation Effects Assessment Project 

Table 25. Cultivated Cropland Exceeding Surface Nitrogen Threshold by SVI Runoff and Rainfall, CEAP II 

SVI Runoff 

Rating 

Average Annual Rainfall 

< 15 inches > 15 and < 25 

inches 

> 25 and < 35 

inches 

> 35 and < 45 

inches > 45 inches 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Low 1,132 11 9,273 16 2,561 6 380 1 521 2 

Moderate 140 6 2,448 26 667 9 674 6 930 6 

Moderately 

High 294 4 855 9 1,998 14 2,165 12 2,175 25 

High 8 0 1,025 21 1,883 20 3,161 24 1,656 42 

National 1,574 7 13,601 16 7,108 10 6,380 8 5,282 10 

25 inches of rainfall and exceeding the surface nitrogen loss threshold increased by 15 percent. 

Of all cultivated cropland acres with a high SVI-R and receiving more than 45 inches of rain 

annually, 42 percent (1.7 million acres) exceeded the surface nitrogen threshold, reflecting the 

difficulty in managing losses under these conditions. 

Cultivated cropland exceeding the surface nitrogen threshold declined overall and in most 

regions between CEAP I and CEAP II (fig. 37). Exceeding acres with high or moderately high 

runoff vulnerability declined in all but the East Central, Northern Plains, Northeast, and South 

Central. In the Northern Plains, the largest increase was in low vulnerability acres exceeding the 

surface nitrogen loss threshold, reflecting the increase in nutrient application rates and decline in 

nutrient incorporation in the region. In two regions (Northern Plains and South Central) more 

than 20 percent of the regional cultivated cropland acres exceeded the surface nitrogen threshold 

due to a mix of factors related to climate and cropping systems. 

Figure 37. Cultivated Cropland Exceeding the Surface Nitrogen Threshold by SVI-R and CEAP Survey 
 

 

Conservation Practices on Cultivated Cropland 59 

Sediment-Transported Phosphorus 

Sediment-transported phosphorus losses dropped by 14,000 tons between CEAP I and CEAP II, 

as cultivated cropland acreage exceeding the loss threshold (greater than 3 lbs/a/y) decreased by 

nearly 1.6 million acres (table 26; appendix 2, table A-18). The edge-of-field phosphorus losses 

on acres exceeding the threshold, however, stayed relatively level, suggesting increases in peracre losses. By CEAP II, the 11 percent of acres exceeding the threshold accounted for 61 

percent of the total sediment-transported loss. The 89 percent of acres meeting the threshold had 

a 14-percent reduction in losses over the decade despite an increase of 3.8 million acres. 

Table 26. Sediment-Transported Phosphorus Loss by Threshold, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) Percent Tons (1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Acres (1,000s) 

Percent 

Relative 

to 

CEAP I 

Tons 

(1,000s) 

Percent 

Relative 

to 

CEAP I 

Total 313,065 100 227 100 315,303 100 213 100 2,238 1 -14 -6 

Meeting 

Threshold 277,854 89 97 43 281,673 89 83 39 3,819 1 -13 -14 

Exceeding 

Threshold 35,211 11 130 57 33,630 11 129 61 -1,581 -4 -1 -1 

Most regions experienced a decline in acres exceeding the sediment-transported phosphorus 

threshold; the Northern Plains was a notable exception with an increase of 2 million acres. The 

Southern and Central Plains region had the largest decline in cultivated cropland exceeding the 

threshold, at 1.7 million acres. The region also experienced a net decline in cultivated cropland 

over the decade. The North Central and Midwest region experienced the largest increase in 

cultivated cropland meeting the threshold, gaining 4.2 million acres between the survey periods 

(fig. 38). 

Rainfall and inherent soil runoff vulnerability are the primary forces driving sedimenttransported phosphorus loss from cultivated cropland. Of the 33.6 million cultivated cropland 

acres exceeding the loss threshold in CEAP II, most were in areas receiving more than 25 inches 

of rainfall annually, nearly 26 million acres (77 percent) and of these most were in high and 

moderately high vulnerability categories (65 percent) (table 27). Unexpected is the number of 

low-runoff-vulnerability acres exceeding the threshold (33 percent of all cultivated cropland with 

low runoff vulnerability), suggesting the effects of increased nutrient application rates and 

reduction in nutrient incorporation. Of all cultivated cropland acres with a high SVI-R and 

receiving more than 45 inches of rain annually, 55 percent (2.1 million acres) exceeded the 

sediment-transported phosphorus threshold, reflecting the difficulty in managing losses under 

these wet conditions. 
 

 

 

 

60 Conservation Effects Assessment Project 

Figure 38. Cultivated Cropland Relative to Sediment-Transported Phosphorus Loss Threshold (Acres and 

Tons), CEAP I and CEAP II 
 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 61 

Table 27. Cultivated Cropland Exceeding Sediment-Transported Phosphorus Threshold by SVI Runoff and 

Rainfall, CEAP II 

SVI Runoff 

Rating 

Average Annual Rainfall 

< 15 inches > 15 and < 25 

inches 

> 25 and < 35 

inches 

> 35 and < 45 

inches > 45 inches 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Low 833 8 4,227 7 2,160 5 2,152 5 1,929 8 

Moderate 25 1 734 8 449 6 791 7 1,559 11 

Moderately 

High 399 5 635 6 2,572 18 2,946 17 2,949 33 

High 38 2 775 16 2,158 23 4,104 31 2,195 55 

National 1,295 6 6,372 8 7,339 10 9,992 12 8,633 16 

Cultivated cropland exceeding the sediment-transported phosphorus threshold declined overall 

and in most regions between CEAP I and CEAP II (fig. 39). Nationally, acres exceeding the 

threshold with high runoff vulnerability remained relatively stable, acres with moderately high 

and low vulnerability increased significantly, and acres with moderate vulnerability declined. 

The Northern Plains and Southern Plains regions each had a significant increase in lowvulnerability acres exceeding the sediment-transported phosphorus loss threshold, reflecting the 

increase in nutrient application rates and decline in nutrient incorporation in those regions. In 

three regions (East Central, Northeast, and South Central) more than 20 percent of the regional 

cultivated cropland acres exceeded the sediment-transported phosphorus threshold due to a mix 

of factors related to climate and cropping systems. While most regions followed the national 

pattern, there were exceptions, notably the North Central and Midwest region, which had an 

increase in high vulnerability acres (over 1 million acres) and a decrease in low vulnerability 

acres (2.4 million acres) exceeding the threshold. 

Figure 39. Cultivated Cropland Exceeding Sediment-Transported Phosphorus Threshold by Region and SVIR, CEAP I and CEAP II 
 

 

 

62 Conservation Effects Assessment Project 

Subsurface Nitrogen 

Although most acres met the subsurface nitrogen threshold in both survey periods, subsurface 

nitrogen losses increased by 420,000 tons between CEAP I and CEAP II (table 28; appendix 2, 

table A-19). Conservation tillage systems reduced the risk of nitrogen loss through surface 

pathways and increased infiltration for subsurface flow, while the increase in surface application 

of fertilizer promoted surface conversion to soluble nitrogen and movement through the soil 

profile. Cultivated cropland exceeding the subsurface loss threshold (greater than 25 lbs/a/y) 

increased by over 14 million acres (19 percent), while acres meeting the threshold declined by 

almost 12 million acres (5 percent). Losses from acres exceeding the threshold increased by 

442,000 tons, resulting in losses 20 percent higher than the CEAP I level and only slightly offset 

by the decline in losses from acres meeting the threshold. 

Table 28. Subsurface Nitrogen Loss by Threshold, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) Percent Tons (1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Acres (1,000s) 

Percent 

Relative 

to 

CEAP I 

Tons 

(1,000s) 

Percent 

Relative 

to 

CEAP I 

Total 313,065 100 3,130 100 315,303 100 3,550 100 2,238 1 420 13 

Meeting 

Threshold 238,286 76 971 31 226,389 72 949 27 -11,897 -5 -22 -2 

Exceeding 

Threshold 74,779 24 2,159 69 88,914 28 2,601 73 14,135 19 442 20 

By CEAP II, 28 percent of cultivated cropland acres exceeded the subsurface nitrogen loss 

threshold and accounted for 73 percent of the total subsurface nitrogen losses (fig. 40). About 

half of the acres that met the subsurface threshold were losing less than 13 lbs/a/y. Timing 

nutrient applications with crop demand and incorporating applications are particularly critical 

practices as there are few edge-of-field options for trapping subsurface flow. In addition, without 

attention to timing and incorporation, increased rates may even lead to reduced yields as 

increased losses reduce nutrient-use efficiencies. 

The North Central and Midwest and the Northern Plains regions accounted for 76 percent of the 

total increase in acres exceeding the subsurface loss threshold, each having individual increases 

of over 5 million acres. In the Northern Plains region, that increase more than doubled the acres 

exceeding the threshold. In the larger North Central and Midwest region, 31 percent of cultivated 

cropland exceeded the subsurface nitrogen loss threshold in CEAP II, an increase of 17 percent 

from CEAP I levels (fig. 40). 

Rainfall and inherent soil leaching vulnerability are the primary forces driving subsurface 

nitrogen loss from cultivated cropland. Of the 88.9 million cultivated cropland acres exceeding 

the loss threshold in CEAP II, nearly 55 million acres (62 percent) were in areas receiving more 

than 35 inches of rainfall annually. Of these acres, 60 percent were in high and moderately high 

leaching vulnerability categories (table 29). Across all rainfall categories, most of the acres 

exceeding the threshold were in the high (39 percent) or moderate (35 percent) leaching 

vulnerability categories. Of all cultivated cropland acres with a high SVI-L and receiving more 

than 45 inches of rain annually, 57 percent (7.3 million acres) exceeded the subsurface nitrogen 

threshold, reflecting the difficulty in managing subsurface losses under high rainfall conditions. 
 

 

 

Conservation Practices on Cultivated Cropland 63 

Figure 40. Cultivated Cropland Relative to Subsurface Nitrogen Loss Threshold (Acres and Tons), CEAP II 
 

 

 

 

 

 

 

64 Conservation Effects Assessment Project 

Table 29. Cultivated Cropland Exceeding Subsurface Nitrogen Threshold by SVI Leaching (SVI-L) and 

Rainfall, CEAP II 

SVI 

Leaching 

Rating 

Average Annual Rainfall 

< 15 inches > 15 and < 25 

inches 

> 25 and < 35 

inches 

> 35 and < 45 

inches > 45 inches 

Acres 

(1,000s) 

Percent 

of SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Low 186 9 463 12 1,469 20 2,321 22 2,303 39 

Moderate 2,551 15 6,289 12 5,264 14 9,290 30 8,082 47 

Moderately 

High 110 21 1,229 23 1,367 30 4,701 41 8,412 51 

High 826 30 5,687 29 8,574 34 12,462 41 7,326 57 

National 3,673 16 13,669 17 16,675 23 28,775 35 26,123 50 

Cultivated cropland exceeding the subsurface nitrogen threshold increased overall and in most 

regions between CEAP I and CEAP II (fig. 41). Acres exceeding the threshold with high, 

moderate, and low leaching vulnerability increased, while there was a slight decline in 

moderately high acres. The North Central and Midwest and Northern Plains regions each had a 

significant increase in high vulnerability acres exceeding the surface nitrogen loss threshold. The 

Southwest was the only region with a decline in acres exceeding the threshold in all vulnerability 

categories. In nine regions more than 20 percent of the regional cultivated cropland acres 

exceeded the subsurface nitrogen threshold reflecting the decline in nutrient management that 

occurred between the surveys and the difficulties in controlling subsurface flow. 

Figure 41. Cultivated Cropland Exceeding Subsurface Nitrogen Threshold by SVI-L and CEAP Survey 

Soluble Phosphorus 

Soluble phosphorus losses increased by 7,200 tons (11 percent) between the survey periods 

(table 30; appendix 2, table A-20). Cultivated cropland exceeding the soluble phosphorus loss 

threshold (greater than 0.5 lbs/a/y) increased by 11.4 million acres (16 percent) while acres 

meeting the threshold declined by 9.2 million acres (4 percent). Phosphorus losses from acres 

exceeding the threshold increased by 6,600 tons, or 15 percent from CEAP I levels, and 
 

 

 

Conservation Practices on Cultivated Cropland 65 

increased slightly on acres meeting the threshold. By CEAP II, 27 percent of cultivated cropland 

acres exceeded the threshold and accounted for 73 percent of the total soluble phosphorus losses. 

The probability of meeting the soluble loss threshold is increased with incorporation of applied 

nutrients, which becomes more important as rates increase. 

Table 30. Soluble Phosphorus Loss by Threshold, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) Percent Tons (1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Acres (1,000s) 

Percent 

Relative to 

CEAP I 

Tons 

(1,000s) 

Percent 

Relative to 

CEAP I 

Total 313,065 100 63 100 315,303 100 70 100 2,238 1 7.2 11 

Meeting 

Threshold 240,156 77 18 29 230,942 73 19 27 -9,214 -4 0.6 3 

Exceeding 

Threshold 72,909 23 45 71 84,361 27 51 73 11,452 16 6.6 15 

Most regions experienced an increase in acres exceeding the soluble phosphorus loss threshold. 

The North Central and Midwest region had an increase of nearly 9 million acres exceeding the 

threshold by CEAP II, more than twice that of the other gaining regions. The Northern Plains 

gained nearly 2.5 million acres meeting the threshold, while most regions lost acres in that 

category (fig. 42). 

Rainfall and inherent soil runoff vulnerability are the primary forces driving soluble phosphorus 

loss from cultivated cropland. Of the 84.4 million cultivated cropland acres exceeding the loss 

threshold in CEAP II, most were in areas receiving 35 inches or more of rainfall annually— 

nearly 74 million acres (88 percent)—and of these nearly 50 percent had low runoff vulnerability 

(table 31). Across all rainfall categories, about half of the acres exceeding the threshold (41.7 

million acres) had low runoff vulnerability. Of all cultivated cropland acres with a high SVI-R 

and receiving more than 45 inches of rain annually, 79 percent (3.1 million acres) exceeded the 

soluble phosphorus threshold, reflecting the difficulty in managing soluble losses under high 

rainfall conditions. 

Cultivated cropland exceeding the soluble phosphorus threshold increased overall and in most 

regions between CEAP I and CEAP II (fig. 43). Acres exceeding the threshold with high, 

moderately high, and low runoff vulnerability increased, while there was a slight decline in 

moderate vulnerability acres. The North Central and Midwest had a significant increase in high 

vulnerability acres exceeding the threshold and was joined by the Lower Mississippi and Texas 

Gulf Coast in a substantial increase in low vulnerability acres exceeding the threshold. In six 

regions more than 20 percent of the regional cultivated cropland acres exceeded the soluble 

phosphorus threshold reflecting the decline in nutrient management that occurred between the 

surveys and the challenges in controlling soluble flow. 
66 Conservation Effects Assessment Project 

Figure 42. Cultivated Cropland Relative to Soluble Phosphorus Loss Threshold (Acres and Tons), CEAP I 

and CEAP II 
 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 67 

Table 31. Cultivated Cropland Exceeding Soluble Phosphorus Threshold by SVI Runoff and Rainfall, CEAP 

II 

SVI Runoff 

Rating 

Average Annual Rainfall 

< 15 inches > 15 and < 25 

inches 

> 25 and < 35 

inches 

> 35 and < 45 

inches > 45 inches 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Low 345 3 1,022 2 4,664 11 17,768 43 17,953 71 

Moderate 85 4 38 0 870 12 4,834 42 11,335 78 

Moderately 

High 92 1 120 1 1,863 13 6,505 37 6,838 77 

High 38 2 198 4 1,034 11 5,619 43 3,141 79 

National 560 2 1,377 2 8,431 11 34,725 42 39,267 75 

Figure 43. Cultivated Cropland Exceeding Soluble Phosphorus Threshold by Region and SVI-R, CEAP I and 

CEAP II 

Soil Carbon 

Between the CEAP surveys, soil carbon gains on all cultivated cropland increased by over 8.8 

million tons per year because of soil-conserving measures applied by farmers. By CEAP II, 

cultivated cropland meeting the soil carbon threshold (gaining or maintaining soil carbon) 

increased by 3.4 million acres; cultivated cropland gaining carbon increased by 25.7 million 

acres and cultivated cropland maintaining soil carbon declined by 22.3 million acres. Cultivated 

cropland exceeding the threshold (losing carbon) declined slightly (1.2 million acres) (fig. 44). 

Average soil carbon change on all cultivated cropland increased from 144 to 192 lbs/a/y (33 

percent). On the nearly 19 million acres where cover crops were part of the rotation in CEAP II, 

rates of carbon gain were nearly 30 percent above the average gain on cultivated cropland where 

cover crops were not in use (box 7, page 69). 

Most regions had soil carbon gains between the two survey periods (fig. 45). Three regions, led 

by the Southern and Central Plains, accounted for 75 percent of the total increase. These regions 

also experienced significant increases in conservation tillage between the two CEAP surveys. 
 

 

 

68 Conservation Effects Assessment Project 

Figure 44. Cultivated Cropland by Carbon Trend, CEAP I and CEAP II 

Figure 45. Carbon Change by Region, CEAP I and CEAP II 

As expected, most soils gaining carbon are under continuous no-till or reduced tillage, 41 and 37 

percent respectively. However, more than 22 percent of acres under conventional tillage also 

gained carbon, demonstrating that there are strategies that work for all tillage classes (fig. 46). 

Nevertheless, nearly 60 percent of all acres losing carbon are conventionally tilled and could 

benefit from additional conservation. 

Multiple management and natural resource factors affect soil carbon storage. Inherent soil 

vulnerability to erosion and runoff losses, low-residue cropping systems, and nutrient 

management strategies that limit plant growth all can contribute to soils not maintaining or 

gaining soil carbon. Of the 48.5 million cultivated cropland acres exceeding the carbon threshold 

in CEAP II, over one-third were receiving between 15 and 25 inches of rainfall annually, and of 

these most had low runoff vulnerability (table 32). Across all rainfall categories, about 60 

percent of the exceeding acres (28.9 million acres) had low runoff vulnerability, up from 57 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 69 

percent in CEAP I. Of all cultivated cropland acres with a high SVI-R and receiving more than 

45 inches of rain annually, only 15 percent exceeded the carbon threshold, suggesting that while 

rainfall and inherent vulnerability may affect soil carbon, other factors could have more 

influence. 

Three regions—North Central and Midwest, Northern Plains, and Lower Mississippi and Texas 

Gulf Coast—drove the increase in cultivated cropland with low runoff vulnerability and 

exceeding the carbon threshold between the survey periods (fig. 47; appendix 2, table A-21). 

Box 7. Cover Crop Benefits 

The estimated benefits on cultivated cropland with cover crops in CEAP II was compared to simulated losses with the cover 

crops removed from the rotation. With cover crops, the losses of sediment were reduced by 17 percent, total nitrogen by 17 

percent, and total phosphorus by 9 percent. Annual change in soil carbon increased by 30 percent. 

Effects of Cover Crops on Selected Benefits 

Benefit Summary 

With Cover 

Crop 

Without Cover 

Crop Cover Crop Benefit 

Tons/Year Percent 

Sediment Loss 13,244,520 15,987,435 -2,742,915 -17 

Total Nitrogen Loss 316,390 379,708 -63,318 -17 

Surface Nitrogen Loss 42,720 46,535 -3,815 -8 

Subsurface Nitrogen Loss 273,570 333,173 -59,503 -17 

Total Phosphorus Loss 16,582 18,284 -1,702 -9 

Soluble Phosphorus Loss 4,519 4,758 -239 -5 

Soil Carbon Gain 2,808,210 2,164,961 645,248 30 

Farmers weigh the trade-offs in cover crop management decisions to achieve their objectives. For example, terminating a cover 

crop with intense tillage may diminish its benefits for erosion reduction or soil condition. Conversely, cover crop residues left to 

degrade naturally on the soil surface may contribute to an increase in soluble nitrogen or phosphorus losses. In arid and 

semiarid regions, competition for water between cover and cash crops may affect adoption. Cover crop adoption over the 

decade between the two surveys was highly concentrated in three regions—Atlantic and Gulf Coastal Plains, North Central and 

Midwest, and Northern Plains—where 70 percent of the increase occurred. 

Figure 46. Carbon Trends by Tillage Class, CEAP II 
 

 

 

 

 

 

 

 

70 Conservation Effects Assessment Project 

Table 32. Cultivated Cropland Exceeding the Soil Carbon Threshold by SVI Runoff and Rainfall, CEAP II 

SVI Runoff 

Rating 

Average Annual Rainfall 

< 15 inches > 15 and < 25 

inches 

> 25 and < 35 

inches 

> 35 and < 45 

inches > 45 inches 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent of 

SVI 

Acres 

(1,000s) 

Percent 

of SVI 

Low 2,042 19 12,301 21 6,140 14 5,189 13 3,219 13 

Moderate 373 15 2,008 22 1,310 18 1,738 15 1,888 13 

Moderately 

High 767 10 1,445 15 2,026 14 1,710 10 1,564 18 

High 406 19 932 19 823 9 2,046 16 584 15 

National 3,588 16 16,686 20 10,299 14 10,683 13 7,255 14 

Figure 47. Cultivated Cropland Exceeding the Carbon Threshold by Region and SVI-R, CEAP I and CEAP 

II 

Managing cultivated cropland for soil carbon is a complex process and requires a systems 

approach to avoid negatively affecting other natural resources. For example, while soils gaining 

carbon have lower nitrogen losses than those maintaining or losing carbon, there can still be 

significant nitrogen loss. Soils gaining carbon with a low level of nitrogen management lose 

more nitrogen than soils losing carbon but with a high level of management (table 33). 

Improving soil health and increasing carbon storage in balance with sound nutrient management 

can help to prevent unintended consequences. 

Table 33. Nitrogen and Phosphorus Loss by Carbon Trend and Nutrient Management Level 

Nutrient Management Level 

Carbon Trend 

Gaining 

(>100 lbs/a/y) Maintaining Losing (<-100 lbs/a/y) 

Nitrogen Phosphorus Nitrogen Phosphorus Nitrogen Phosphorus 

lbs/a/y 

Low 47 4.8 76 5.8 105 7.6 

Moderate 23 1.7 38 2.9 61 6 

Moderately High 21 1.1 33 1.5 59 3.7 

High 15 1 19 1.3 36 3.2 
 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 71 

Resource Concerns Summary 

Conservation measures adopted by farmers between CEAP I and CEAP II helped to reduce field 

losses of erosion, sediment, surface nitrogen, sediment-transported phosphorus, and soil carbon. 

Correspondingly, the acres exceeding thresholds for those resource concerns declined as well 

(table 34). However, for subsurface nitrogen and soluble phosphorus losses, acres exceeding loss 

thresholds increased between the survey periods. These losses were driven by changes in nutrient 

management practices and related to changes in cropping patterns. Over one-fourth of the 

Nation’s cultivated cropland exceeded thresholds for subsurface nitrogen and soluble phosphorus 

losses. 

Table 34. Cultivated Cropland Exceeding Resource Concern Thresholds by Survey 

Resource Concern (Loss 

Threshold) 

CEAP I CEAP II CEAP II minus CEAP I 

Acres 

(1,000s) 

Percent of 

Acres 

Acres 

(1,000s) 

Percent of 

Acres 

Acres 

(1,000s) 

Percent of 

Acres 

Relative to 

CEAP I 

Sheet & Rill Erosion (>T) 35,519 11 31,171 10 -4,348 -12 

Wind Erosion (>T) 38,634 12 30,994 10 -7,640 -20 

Sediment (>2 t/a/y) 38,113 12 29,335 9 -8,778 -23 

Surface Nitrogen (>15 lbs/a/y) 35,084 11 33,946 11 -1,138 -3 

Sediment-Transported 

Phosphorus (>3lbs/a/y) 35,211 11 33,630 11 -1,581 -4 

Subsurface Nitrogen (>25 lbs/a/y) 74,779 24 88,914 28 14,135 19 

Soluble Phosphorus (>0.5 lbs/a/y) 72,909 23 84,361 27 11,452 16 

Soil Carbon (Maintaining/Losing) 49,703 16 48,511 15 -1,192 -2 

The acres exceeding thresholds are not additive, and a single field or a single acre may exceed 

more than one threshold. For example, an acre exceeding the sheet and rill erosion threshold may 

also exceed the sediment loss threshold. Similarly, opportunities remain where conservation 

measures are in place but the pressures on the land require more comprehensive treatment. For 

example, regions with intense rainfall, steeper slopes, or prevalence of low residue, intensive 

cropping systems often require additional conservation practices to meet loss thresholds. 

Acres exceeding the thresholds were not evenly distributed, reflecting regional differences in 

climate, soils, production practices, and crops, among others. Cultivated cropland exceeding the 

wind threshold, for example, was concentrated in several western regions with arid and semiarid 

conditions. Water-driven resource concerns such as subsurface nitrogen losses were concentrated 

in regions with high rainfall and flatter terrain. Regional treatment priorities can be informed by 

the percentage of regional acres exceeding resource concern thresholds (table 35). For example, 

in the Northeast region, where nearly 50 percent of cultivated cropland exceeded the subsurface 

nitrogen threshold and nearly 60 percent of the acres exceeded the soluble phosphorus threshold, 

nutrient management would be a priority. 

In most cases, cultivated cropland acres needing treatment to meet a resource concern threshold 

are not contiguous but exist as isolated areas within larger fields—for example, soils vulnerable 

to leaching within a field (box 8). Making progress begins with a field-scale resource assessment 

and conservation planning to design workable solutions in balance with an operator’s economic 

and environmental objectives. Solutions may include targeted conservation practices within a 

systems approach, higher end technology, or some combination of these and other tools. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

72 Conservation Effects Assessment Project 

Table 35. Percent Regional Acres Exceeding by Threshold, CEAP II * 

Region Wind 

Erosion 

Sheet & 

Rill 

Erosion 

Sediment Surface 

Nitrogen 

Sediment 

Transported 

Phosphorus 

Subsurface 

Nitrogen 

Soluble 

Phosphorus Carbon 

Atlantic and Gulf 

Coastal Plains 0.0 14.5 12.0 3.5 11.6 59.7 68.9 15.1 

California 

Coastal 0.0 1.0 5.1 1.3 1.6 33.5 17.0 38.7 

East Central 0.0 32.0 28.2 17.4 27.0 49.7 73.6 13.6 

Lower Mississippi 

and Texas Gulf 2.6 16.3 24.4 10.9 13.6 47.3 77.6 14.2 

North Central and 

Midwest 1.5 13.2 11.0 7.3 11.1 31.1 32.5 12.8 

Northeast 0.0 31.5 23.2 13.8 30.7 49.6 58.9 20.3 

Northern Plains 24.0 1.5 1.5 22.4 9.3 19.5 1.5 19.8 

Northwest 13.9 0.6 3.5 4.5 6.2 20.0 6.5 13.9 

South Central 2.1 28.5 32.6 26.0 23.9 40.0 50.6 29.6 

Southern and 

Central Plains 21.6 2.2 1.8 9.2 5.5 10.8 2.2 14.1 

Southwest 25.2 2.8 3.8 4.5 4.3 24.0 9.2 25.2 

National 9.8 9.9 9.3 10.8 10.7 28.2 26.8 15.4 

* The highlighted cells indicate a regional percentage above the national average 

Box 8. Treatment Needs at the Field Level 

Within a given farm field, measures needed to meet resource concern thresholds vary, reflecting the diversity of soils and 

vulnerabilities and highlighting the need for comprehensive conservation planning and integration of modern technologies such 

as precision agriculture to address needs more efficiently. The acres exceeding surface or subsurface loss thresholds are 

generally scattered, manifested as small, vulnerable inclusions in a larger field. The figure below shows a typical Midwestern 

field with a combination of soils with low, moderate, and high vulnerability to runoff. In most cases, eliminating cultivation on 

high and moderately high-risk soils embedded in a field is unrealistic, operationally and economically. Variable rate technology 

(VRT) allows precision application of nitrogen or other inputs based on variations in the soil or the crop offering one method for 

treating fields with multiple vulnerability zones. Where high risk acres are contiguous, at field edges or corners, conversion to 

less intensive uses may prove economically effective. Irrespective of approach, addressing vulnerable soils and their needs 

depends on conservation planning and targeting within the field to develop workable subfield treatments that minimize 

potential losses. 
Conservation Practices on Cultivated Cropland 73 

HOW DID SEDIMENT AND NUTRIENT MANAGEMENT CHANGE? 

Cultivated cropland acres were categorized by the level of sediment, nitrogen, and phosphorus 

management being applied to allow comparison of conservation treatment between the two 

CEAP survey periods. Combinations of soils, climate, and crop rotations are a few factors that 

may affect the management level needed to maintain the resource. In general, higher levels of 

management are needed as annual rainfall and soil vulnerability increase. 

Cultivated cropland acres were placed into one of four management levels—high, moderately 

high, moderate, and low—that consider the agricultural system in its entirety and the interactions 

and potential effects of operational and conservation activities on the land. The criteria are based 

on an Avoid, Control, and Trap approach to reducing sediment losses, and a Rate, Method, and 

Timing approach to reducing nutrient losses from cultivated cropland (appendix 3). This systems 

approach uses a mix of conservation practices tailored to the resource concern to minimize loss 

potential and optimize agricultural inputs for productivity. As management levels increase, more 

supporting practices are included. 

The level of sediment, nitrogen, and phosphorus management on cultivated cropland changed 

over the decade between the CEAP surveys, reflecting the shifts in conservation treatment. The 

increase in conservation tillage and structural practices had a positive effect, most notably in 

sediment management, but also in nitrogen and phosphorus management where some gains were 

made in moderately high management levels. In contrast, the decline in nutrient management 

practices, particularly increased application rates and incorporation declines, drove large drops in 

high levels of management for nitrogen and phosphorus and corresponding increases in low 

levels of management of both. 

Sediment 

Cultivated cropland with moderately high and high sediment management increased by 45 

million acres, from 25 percent of acres in CEAP I to 40 percent of acres in CEAP II, reflecting 

farmers’ increased adoption of conservation tillage and structural practices (table 36; appendix 2, 

table A-22). By CEAP II, acres with high sediment management had increased by 150 percent 

and acres with moderately high sediment management increased by 42 percent, while those in 

moderate and low levels declined by 43 million acres (18 percent) as more cultivated cropland 

moved to higher sediment management levels (fig. 48). Despite a 9-percent decline in acres with 

moderate management levels and a 37-percent decline in acres with low management levels, 

some 60 percent of cultivated cropland remained under moderate or low management for 

sediment control. 
 

 

 

 

 

 

 

74 Conservation Effects Assessment Project 

Table 36. Sediment Management Levels on Cultivated Cropland, CEAP I and CEAP II 

CEAP I CEAP II CEAP II minus CEAP I Percent 

Change in 

Acres from 

CEAP I 

Management 

Level Acres 

(1000) Percent Acres (1000) Percent Acres (1000) Percent 

National 313,065 315,303 2,238 1 

High 10,332 3 25,816 8 15,484 5 150 

Moderately 

High 69,900 22 99,490 32 29,590 10 42 

Moderate 155,923 50 141,210 45 -14,713 -5 -9 

Low 76,910 25 48,787 15 -28,123 -10 -37 

Figure 48. Cultivated Cropland by Sediment Management Level, CEAP I and CEAP II 

Production regions generally followed the national trend, with most showing increases in 

moderately high and high sediment management and declines in moderate and low management 

levels. Gains were concentrated in two regions—North Central and Midwest and Southern and 

Central Plains (fig. 49). Together these regions accounted for three-fourths of the total increase 

in cultivated cropland with moderately high and high levels of sediment management (33.7 

million acres). 

Sediment Management by Tillage System 

The increase in conservation tillage and particularly in continuous no-till drove the increases in 

sediment management levels experienced between CEAP I and CEAP II. Cultivated cropland 

under reduced tillage and continuous no-till increased by 53 million acres; 83 percent of this 

increased acreage was in high and moderately high levels of sediment management. Continuous 

no-till with high sediment management increased by over 9 million acres (239 percent) (table 

37). Conventional tillage experienced declines in all but the moderately high management 

category, aligning with the general loss of acres under that form of tillage (fig. 50). 
 

 

Conservation Practices on Cultivated Cropland 75 

Figure 49. Sediment Management Levels on Cultivated Cropland by Region, CEAP I and CEAP II 
 

 

 

 

 

 

76 Conservation Effects Assessment Project 

Table 37. Sediment Management on Cultivated Cropland by Tillage System and CEAP Survey 

Tillage System / 

Sediment 

Management Level 

CEAP I CEAP II CEAP II minus CEAP I Percent 

Change in 

Acres from 

CEAP I 

Acres 

(1,000s) Percent Acres (1,000s) Percent Acres (1,000s) Percent 

Conventional Tillage 155,941 50 104,771 33 -51,170 -17 -33 

High 0 0 0 0 0 0 0 

Moderately High 3,005 2 3,902 4 897 2 30 

Moderate 76,026 49 52,082 50 -23,943 1 -31 

Low 76,910 49 48,787 47 -28,123 -3 -37 

Reduced Tillage 95,572 31 107,423 34 11,851 4 12 

High 6,515 7 12,868 12 6,353 5 98 

Moderately High 39,240 41 48,013 45 8,772 4 22 

Moderate 49,817 52 46,543 43 -3,274 -9 -7 

Low 0 0 0 0 0 0 0 

Continuous No-Till 61,553 20 103,108 33 41,555 13 68 

High 3,817 6 12,948 13 9,131 6 239 

Moderately High 27,655 45 47,575 46 19,920 1 72 

Moderate 30,081 49 42,585 41 12,505 -8 42 

Low 0 0 0 0 0 0 0 

National 313,065 315,303 2,238 1 

High 10,332 3 25,816 8 15,484 5 150 

Moderately High 69,900 22 99,490 32 29,589 9 42 

Moderate 155,924 50 141,210 45 -14,712 -5 -9 

Low 76,910 25 48,787 15 -28,123 -9 -37 

Figure 50. Cultivated Cropland by Sediment Management Level and Tillage System, CEAP II minus CEAP I 
 

 

 

 

 

Conservation Practices on Cultivated Cropland 77 

Sediment Management on Vulnerable Acres 

Between CEAP I and CEAP II, sediment management on cultivated cropland with high and 

moderately high vulnerability to runoff (soil vulnerability index runoff [SVI-R]) increased, 

reflecting the consistent movement into higher management levels (table 38; appendix 2, table 

A-25). High and moderately high sediment management on high vulnerability acres increased by 

9.5 million acres and by 11.8 million acres on cultivated cropland with moderately high runoff 

vulnerability. 

Table 38. Sediment Management Levels by Soil Vulnerability Index Runoff (SVI-R), CEAP I and CEAP II 

Sediment 

Management Level 

SVI R Rating 

High Moderately High Moderate Low National 

Acres 

(1,000s) 

Percent 

SVI 

Acres 

Acres 

(1,000s) 

Percent 

SVI Acres 

Acres 

(1,000s) 

Percent 

SVI 

Acres 

Acres 

(1,000s) 

Percent 

SVI Acres 

Acres 

(1,000s) 

CEAP I 

High 2,516 9 2,169 4 1,401 3 4,245 2 10,332 

Moderately High 10,674 39 16,714 31 9,815 18 32,697 18 69,900 

Moderate 11,368 42 25,638 48 26,419 48 92,498 52 155,923 

Low 2,587 10 9,200 17 16,899 31 48,225 27 76,910 

National 27,145 9 53,721 17 54,534 17 177,665 57 313,065 

CEAP II 

High 6,884 21 6,438 11 2,477 6 10,018 6 25,816 

Moderately High 15,793 47 24,266 42 11,003 25 48,429 27 99,490 

Moderate 9,363 28 23,277 40 23,269 52 85,300 48 141,210 

Low 1,492 4 4,184 7 8,033 18 35,079 20 48,787 

National 33,532 11 58,165 18 44,781 14 178,825 57 315,303 

CEAP II minus CEAP I 

High 4,367 11 4,269 7 1,076 3 5,773 3 15,484 

Moderately High 5,119 8 7,552 11 1,187 7 15,732 9 29,590 

Moderate -2,005 -14 -2,361 -8 -3,149 4 -7,198 -4 -14,713 

Low -1,094 -5 -5,016 -10 -8,866 -13 -13,147 -8 -28,123 

National 6,387 2 4,444 1 -9,753 -3 1,161 0 2,238 

Change Relative to CEAP I 

High 4,367 174 4,269 197 1,076 77 5,773 136 15,484 

Moderately High 5,119 48 7,552 45 1,187 12 15,732 48 29,590 

Moderate -2,005 -18 -2,361 -9 -3,149 -12 -7,198 -8 -14,713 

Low -1,094 -42 -5,016 -55 -8,866 -52 -13,147 -27 -28,123 

National 6,387 24 4,444 8 -9,753 -18 1,161 1 2,238 

While high and moderately high sediment management levels increased in all vulnerability 

ratings, the largest percentage increases were in the higher runoff vulnerability classes (high and 

moderately high SVI-R) (fig. 51). Low sediment management was the reverse, declining in all 

runoff vulnerability classes and reflecting the adoption of conservation tillage and structural 

practices designed to control erosion and runoff. 
 

 

 

 

 

 

78 Conservation Effects Assessment Project 

Figure 51. Change in Sediment Management on Cultivated Cropland by SVI-R, CEAP II minus CEAP I 

Nitrogen 

Between CEAP I and CEAP II, cultivated cropland with high nitrogen management declined by 

over 36 million acres (27 percent), while acres with moderately high nitrogen management 

increased by nearly 17 million acres (16 percent) (table 39; appendix 2, table A-23). By CEAP 

II, cultivated cropland with moderately high nitrogen management had become the dominant 

management class on cultivated cropland. 

In contrast, cultivated cropland with moderate and low nitrogen management increased by nearly 

21.7 million acres, reflecting the decline in nutrient management practices between the surveys 

(fig. 52). In CEAP II, over 70 percent of cultivated cropland was under high or moderately high 

nitrogen management, down from 77 percent in CEAP I. 

Table 39. Nitrogen Management Levels on Cultivated Cropland, CEAP I and CEAP II 

Nitrogen 

Management 

Level 

CEAP I CEAP II CEAP II minus CEAP I Percent 

Change in 

Acres from 

CEAP I 

Acres 

(1000) Percent Acres (1000) Percent Acres (1000) Percent 

National 313,065 315,303 2,238 1 

High 136,007 43 99,850 32 -36,158 -12 -27 

Moderately High 106,224 34 122,954 39 16,730 5 16 

Moderate 22,213 7 29,220 9 7,008 2 32 

Low 48,620 16 63,279 20 14,659 5 30 
 

 

Conservation Practices on Cultivated Cropland 79 

Figure 52. Cultivated Cropland by Nitrogen Management Level, CEAP I and CEAP II 

Production regions generally followed the national trends. All but the Southwest region 

experienced declines in high nitrogen management, and nine regions experienced gains in 

moderately high management. Three regions—North Central and Midwest, Northern Plains, and 

Southern and Central Plains—had the largest declines in high nitrogen management at nearly 31 

million acres, accounting for 86 percent of the total nationwide decline between the survey 

periods. Losses in eight regions were 25 percent or more of the acres in their high nitrogen 

management level in CEAP I. The Northern Plains and Southern and Central Plains led the gains 

in moderately high nitrogen management, accounting for 73 percent of the total increase (fig. 

53). 

Nitrogen Management by Tillage System 

The decline in nitrogen management between the CEAP surveys is concentrated in the 

conventional and reduced tillage systems. The overall decline in high management levels came 

from declines in conventionally tilled and reduced till acres, only partially offset by a slight 

increase in high management in continuous no-till (table 40). While continuous no-till with high 

nitrogen management increased by nearly 6 million acres, high management was a smaller share 

of the tillage class in CEAP II as compared to CEAP I, 29 to 39 percent respectively. In contrast, 

half (26.6 million acres) of the increase in conservation tillage systems (reduced tillage and 

continuous no till) was in low and moderate nitrogen management levels. 

Conventional tillage experienced declines in every nitrogen management level, reflecting the 

general exodus of acres under that form of tillage (fig. 54). Reduced tillage had a decline in high 

nitrogen management (nearly 9 million acres) but increases in moderately high, moderate, and 

low management. Continuous no-till increased in every nitrogen management level, but like 

reduced tillage the largest increases were in moderately high and low nitrogen management, 

accounting for 75 percent of the total increase. 
 

 

80 Conservation Effects Assessment Project 

Figure 53. Nitrogen Management Levels on Cultivated Cropland, CEAP I and CEAP II 
 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 81 

Table 40. Nitrogen Management on Cultivated Cropland by Tillage System and CEAP Survey 

Tillage System / Nitrogen 

Management Level 

CEAP I CEAP II CEAP II minus CEAP 

I 

Percent 

Change 

in Acres 

from 

CEAP I 

Acres 

(1000) Percent Acres (1000) Percent Acres (1000) Percent 

Conventional Tillage 155,941 50 104,771 33 -51,169 -17 -33 

High 69,647 45 36,231 35 -33,416 -10 -48 

Moderately High 48,703 31 35,915 34 -12,788 3 -26 

Moderate 9,504 6 7,582 7 -1,922 1 -20 

Low 28,086 18 25,044 24 -3,042 6 -11 

Reduced Tillage 95,572 31 107,423 34 11,852 4 12 

High 42,482 44 33,778 31 -8,704 -13 -20 

Moderately High 31,939 33 40,050 37 8,111 4 25 

Moderate 8,128 9 12,554 12 4,426 3 54 

Low 13,023 14 21,041 20 8,018 6 62 

Continuous No-Till 61,553 20 103,108 33 41,556 13 68 

High 23,878 39 29,841 29 5,963 -10 25 

Moderately High 25,583 42 46,989 46 21,406 4 84 

Moderate 4,581 7 9,084 9 4,503 1 98 

Low 7,512 12 17,195 17 9,683 4 129 

National 313,065 315,303 2,238 1 

High 136,007 43 99,850 32 -36,157 -12 -27 

Moderately High 106,225 34 122,954 39 16,729 5 16 

Moderate 22,213 7 29,220 9 7,007 2 32 

Low 48,621 16 63,280 20 14,659 5 30 

Figure 54. Nitrogen Management Level by Tillage System, CEAP II minus CEAP I 
 

 

 

 

82 Conservation Effects Assessment Project 

The downward shifts in nitrogen management levels reflect the decline in incorporation of 

applied nitrogen. Conversion to no-till and reduced tillage systems requires nutrient management 

changes. Incorporation techniques such as injection, knifing, or banding are needed, and these 

techniques may also require a different nutrient form. For example, no-till may not be an option 

with existing equipment and solid forms of manure because some level of incorporation is 

required. 

Nitrogen Management on Vulnerable Acres 

Cultivated cropland with high and moderately high soil vulnerability index ratings for leaching 

(SVI-L) needs more intensive nitrogen management to reduce the potential for nitrogen losses. 

Between the survey periods, the extent of cultivated cropland with high vulnerability (high SVIL) changed little (less than 1 percent), while acres with moderately high vulnerability 

(moderately high SVI-L) declined by 16 percent. By CEAP II, 41 percent of cultivated cropland 

was in these two vulnerability classes (table 41; appendix 2, table A-26). 

Between the surveys, high nitrogen management on high and moderately high SVI-L acres 

declined by over 16 million acres; a nearly 30-percent reduction for each vulnerability group 

from CEAP I levels. In contrast, cultivated cropland in the riskiest combination of high and 

moderately high SVI-L and low nitrogen management increased by over 4 million acres, and 

most (86 percent) was high SVI-L acres. By CEAP II, 67 percent of high and moderately high 

vulnerability cropland were under high or moderately high levels of nitrogen management, down 

from 75 percent in CEAP I. Between the two surveys, higher levels of nitrogen management 

declined on the most vulnerable acres while lower levels of nitrogen management increased (fig. 

55). 

Table 41. Nitrogen Management Levels by Soil Vulnerability Index Leaching, CEAP I and CEAP II 

Nitrogen 

Management 

Level 

SVI-L Rating 

High Moderately High Moderate Low National 

Acres 

(1,000s) 

Percent 

SVI 

Acres 

Acres 

(1,000s) 

Percent 

SVI 

Acres 

Acres 

(1,000s) 

Percent 

SVI 

Acres 

Acres 

(1,000s) 

Percent 

SVI 

Acres 

Acres 

(1,000s) 

CEAP I 

High 37,561 41 17,459 38 73,169 46 7,819 45 136,007 

Moderately High 31,637 35 16,160 35 52,543 33 5,884 34 106,224 

Moderate 7,394 8 4,687 10 9,151 6 981 6 22,213 

Low 14,921 16 7,749 17 23,282 15 2,668 15 48,620 

National 91,513 29 46,055 15 158,145 51 17,351 6 313,065 

CEAP II 

High 26,523 29 12,399 32 51,809 33 9,118 31 99,850 

Moderately High 34,158 37 14,348 37 61,970 40 12,477 42 122,954 

Moderate 11,733 13 3,605 9 11,116 7 2,767 9 29,220 

Low 18,867 21 8,381 22 30,520 20 5,512 18 63,279 

National 91,281 29 38,732 12 155,416 49 29,874 9 315,303 

CEAP II minus CEAP I 

High -11,037 -12 -5,060 -6 -21,359 -13 1,299 -15 -36,158 

Moderately High 2,521 3 -1,812 2 9,427 7 6,594 8 16,730 

Moderate 4,339 5 -1,082 -1 1,965 1 1,786 4 7,008 

Low 3,945 4 631 5 7,238 5 2,844 3 14,659 

National -232 0 -7,323 -2 -2,729 -1 12,522 4 2,238 

Change relative to CEAP I Levels 

High -11,037 -29 -5,060 -29 -21,359 -29 1,299 17 -36,158 

Moderately High 2,521 8 -1,812 -11 9,427 18 6,594 112 16,730 

Moderate 4,339 59 -1,082 -23 1,965 21 1,786 182 7,008 

Low 3,945 26 631 8 7,238 31 2,844 107 14,659 

National -232 <1 -7,323 -16 -2,729 -2 12,522 72 2,238 
 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 83 

Figure 55. Change in Nitrogen Management on Cultivated Cropland by SVI-L, CEAP II minus CEAP I 

Phosphorus 

Between CEAP I and CEAP II, cultivated cropland with high phosphorus management declined 

by nearly 31 million acres, while moderately high management increased by 6.5 million acres; 

together there was a net loss in the higher management levels of 24.5 million acres (table 42; 

appendix 2, table A-24). In contrast, cultivated cropland with moderate and low phosphorus 

management increased by 26.7 million acres. While most cultivated cropland (75 percent) 

remained in high and moderately high phosphorus management in CEAP II, it was down from 83 

percent in CEAP I, reflecting the overall decline in nutrient management practices between the 

surveys. 

By CEAP II, cultivated cropland with high phosphorus management decreased by 15 percent 

from CEAP I levels. Acres in the remaining three management levels increased between 14 and 

53 percent (fig. 56). 

Table 42. Phosphorus Management Levels on Cultivated Cropland, CEAP I and CEAP II 

Management 

Level 

CEAP I CEAP II CEAP II minus CEAP I Percent 

Change in 

Acres from 

CEAP I 

Acres 

(1000) Percent Acres (1000) Percent Acres (1000) Percent 

National 313,065 315,303 2,238 1 

High 212,703 68 181,711 58 -30,992 -10 -15 

Moderately High 47,086 15 53,549 17 6,463 2 14 

Moderate 37,130 12 56,902 18 19,772 6 53 

Low 16,146 5 23,140 7 6,994 2 43 
 

 

84 Conservation Effects Assessment Project 

Figure 56. Cultivated Cropland by Phosphorus Management Level, CEAP I and CEAP II 

While six regions each had more than 1 million acres exit from high management, two regions— 

North Central and Midwest and Southern and Central Plains—accounted for most of the loss 

(fig. 57). Together these regions accounted for 65 percent of the total decline in cultivated 

cropland with a high level of phosphorus management (23.1 million acres) and 65 percent of the 

total increase in cultivated cropland with low phosphorus management (4.5 million acres). 

Phosphorus Management by Tillage System 

The changes in tillage between the CEAP surveys are reflected in the changes in phosphorus 

management levels on cultivated cropland. The overall decline in high management levels came 

from declines in conventional tillage and reduced till acres, only partially offset by the increase 

in high management in continuous no-till (table 43). While continuous no-till with high 

phosphorus management increased by 18.1 million acres, it occupied a smaller share of the 

tillage class in CEAP II as compared to CEAP I, dropping from 59 percent to 53 percent between 

the two surveys. In contrast, nearly 54 percent (28.7 million acres) of the increase in 

conservation tillage systems (reduced tillage and continuous no-till) was in low and moderate 

nitrogen management levels. 

Conventionally tilled acres experienced declines in every phosphorus management level, 

reflecting the general exodus of acres under that form of tillage (fig. 58). Phosphorus 

management levels improved on nearly 12 million reduced tillage acres as the decline in high 

phosphorus management (4.1 million acres) was offset by large gains in moderate (8.4 million 

acres), moderately high (6.4 million acres), and low (4.3 million acres) management levels. 

Continuous no-till increased by over 41.5 million acres and in every phosphorus management 

level, but unlike reduced tillage the largest increase was in high phosphorus management (18.2 

million acres), accounting for 44 percent of the total. 
 

 

Conservation Practices on Cultivated Cropland 85 

Figure 57. Phosphorus Management on Cultivated Cropland by Region, CEAP I and CEAP II 
 

 

 

 

 

 

 

86 Conservation Effects Assessment Project 

Table 43. Phosphorus Management on Cultivated Cropland by Tillage System and CEAP Survey 

Tillage System / 

Phosphorus 

Management Level 

CEAP I CEAP II CEAP II minus CEAP 

I 

Percent 

Change 

in Acres 

from 

CEAP I 

Acres 

(1000) Percent Acres (1000) Percent Acres (1000) Percent 

Conventional Tillage 155,941 50 104,771 33 -51,170 -17 -33 

High 112,525 72 67,498 64 -45,027 -8 -40 

Moderately High 18,463 12 14,282 14 -4,181 2 -23 

Moderate 15,194 10 13,828 13 -1,365 3 -9 

Low 9,759 6 9,162 9 -597 2 -6 

Reduced Tillage 95,572 31 107,423 34 11,851 4 12 

High 63,827 67 59,706 56 -4,121 -11 -6 

Moderately High 15,022 16 19,225 18 4,203 2 28 

Moderate 12,900 13 21,333 20 8,433 6 65 

Low 3,823 4 7,160 7 3,337 3 87 

Continuous No Till 61,553 20 103,108 33 41,555 13 68 

High 36,351 59 54,507 53 18,156 -6 50 

Moderately High 13,601 22 20,042 19 6,441 -3 47 

Moderate 9,036 15 21,741 21 12,705 6 141 

Low 2,564 4 6,819 7 4,255 2 166 

National 313,065 315,303 2,238 

High 212,703 68 181,711 58 -30,992 -10 -15 

Moderately High 47,086 15 53,549 17 6,463 2 14 

Moderate 37,130 12 56,902 18 19,773 6 53 

Low 16,146 5 23,141 7 6,995 2 43 

Figure 58. Cultivated Cropland by Phosphorus Management Level and Tillage System, CEAP II minus 

CEAP I 
 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 87 

Phosphorus Management on Vulnerable Acres 

Cultivated cropland with high and moderately high soil vulnerability index ratings for runoff 

(SVI-R) need more intensive management to reduce the potential for phosphorus losses. 

Between the survey periods, the extent of cultivated cropland with high vulnerability (high SVIR) increased by 6.4 million acres (24 percent from CEAP I levels) and acres with moderately 

high vulnerability (moderately high SVI-R) increased by 4.4 million acres (8 percent from CEAP 

I levels) (table 44; appendix 2, table A-27). By CEAP II, 29 percent of cultivated cropland were 

in these two high vulnerability classes. 

Between the surveys, high phosphorus management on high and moderately high SVI-R acres 

declined by nearly 3 million acres (3- and 7-percent reductions from CEAP I levels, 

respectively). In contrast, cultivated cropland in the riskiest combination of high and moderately 

high SVI-R and low phosphorus management increased by over 2.7 million acres. By CEAP II, 

69 percent of high and moderately high vulnerability acres were under high or moderately high 

levels of phosphorus management, down from 79 percent in CEAP I. Between the two surveys, 

higher levels of phosphorus management declined on the most vulnerable acres while lower 

levels of phosphorus management increased (fig. 59). 

Table 44. Phosphorus Management on Cultivated Cropland by Soil Vulnerability Index Runoff (SVI-R) 

Rating, CEAP I and CEAP II 

Phosphorus 

Management 

Level 

SVI R Rating National High Moderately High Moderate Low 

Acres 

(1,000s) 

Percent 

SVI Acres 

Acres 

(1,000s) 

Percent 

SVI Acres 

Acres 

(1,000s) 

Percent 

SVI Acres 

Acres 

(1,000s) 

Percent 

SVI Acres 

Acres 

(1,000s) 

CEAP I 

High 16,656 61 35,159 65 37,269 68 123,619 70 212,703 

Moderately High 3,997 15 7,980 15 9,043 17 26,066 15 47,086 

Moderate 4,601 17 7,454 14 6,224 11 18,851 11 37,130 

Low 1,890 7 3,128 6 1,999 4 9,129 5 16,146 

National 27,145 9 53,721 17 54,534 17 177,665 57 313,065 

CEAP II 

High 16,227 48 32,670 56 26,158 58 106,657 60 181,711 

Moderately High 5,286 16 8,869 15 7,975 18 31,420 18 53,549 

Moderate 9,125 27 11,750 20 7,319 16 28,710 16 56,902 

Low 2,895 9 4,877 8 3,330 7 12,039 7 23,140 

National 33,532 11 58,165 18 44,781 14 178,825 57 315,303 

CEAP II minus CEAP I 

High -429 -13 -2,489 -9 -11,111 -10 -16,962 -10 -30,992 

Moderately High 1,288 1 889 0 -1,068 1 5,354 3 6,463 

Moderate 4,523 10 4,295 6 1,095 5 9,859 5 19,773 

Low 1,005 2 1,749 3 1,331 4 2,910 2 6,994 

National 6,387 2 4,444 1 -9,753 -3 1,161 0 2,238 

Change Relative to CEAP I 

High -429 -3 -2,489 -7 -11,111 -30 -16,962 -14 -30,992 

Moderately High 1,288 32 889 11 -1,068 -12 5,354 21 6,463 

Moderate 4,523 98 4,295 58 1,095 18 9,859 52 19,773 

Low 1,005 53 1,749 56 1,331 67 2,910 32 6,994 

National 6,387 24 4,444 8 -9,753 -18 1,161 1 2,238 
 

 

88 Conservation Effects Assessment Project 

Figure 59. Change in Phosphorus Management on Cultivated Cropland by SVI-R, CEAP II minus CEAP I 
 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 89 

HOW DID THE CONSERVATION CONDITION IN THE CEAP SURVEYS 

COMPARE TO ALTERNATIVE TREATMENT LEVELS? 

Alternative treatment levels were created to simulate the potential benefits from additional 

conservation and the possible tradeoffs in crop productivity or through unintended effects on 

related resource concerns. The estimated loss reductions associated with alternative treatment 

levels were modeled for all cultivated cropland acres irrespective of conservation treatment need. 

Estimates for treating all acres may overstate potential benefits since they include additional 

reductions from acres meeting resource concern thresholds, which would be unlikely to receive 

additional conservation treatment, or the benefit of additional conservation would be small. 

However, comparison of the alternative treatment levels with CEAP I and CEAP II conservation 

conditions provide valuable context for understanding existing conservation benefits. 

The Erosion Control (EC) and Nutrient Management (NM) treatment levels simulate parts of a 

comprehensive plan that addresses the natural resource concerns of the agricultural system. The 

EC is primarily the addition of structural practices designed to control and trap losses from 

cropped fields, while the NM addresses nutrient application method, form, timing, and a 10-

percent reduction in application rate and is designed to avoid excess surface and subsurface 

nutrient losses.28 The Erosion Control and Nutrient Management (ENM) level combines these 

two treatments to simulate a comprehensive plan with improvements to structural conservation 

practices and nutrient management. The ENM is also modeled with only 85 percent of the 

nutrient form being applied (ENM85) plus timing and incorporation adjustments and runoff 

control to improve nutrient-use efficiency. 

While the EC treatment level would control runoff and reduce surface losses that benefit yield, it 

would also encourage infiltration, which can increase subsurface nitrogen losses. Under the NM 

treatment level, the lack of runoff control could increase surface nitrogen, sediment, and total 

phosphorus losses. Without the EC runoff control, the NM rate reduction would fail to achieve 

its purpose of reducing nutrient losses and could negatively affect yield. Thus, the ENM 

treatment level reflects how EC runoff control would support NM reduced nutrient application 

rates, contributing to production and conservation of soil and nutrient inputs. The treatment 

levels demonstrate the benefits of a systems approach that considers multiple resource concerns 

in a conservation treatment. 

Erosion Control and Nutrient Management (ENM) 

Under ENM, structural and nutrient management practices are combined to address all 

applicable resource concerns while maintaining or enhancing productivity as compared to NM 

alone. At the ENM treatment level, all regions would have 87 percent or more of their cultivated 

cropland meeting the thresholds for sediment, wind erosion, surface nitrogen, and total 

phosphorus resource concerns (table 45).29 

28 At a 10-percent reduction, productivity is maintained on most soils while demonstrating the effects of improved use 

efficiency that is provided through rate reductions in combination with improved timing and application methods, particularly 

in precision agriculture systems. 

29 Wind erosion control under ENM reflects the application of structural wind erosion control practices on the most susceptible 

acres, however, these are not widely adopted in the most wind-erosion-prone regions where water supply challenges the use 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

90 Conservation Effects Assessment Project 

Table 45. Estimated Percent of Cultivated Cropland Acres Meeting Resource Concern Thresholds under 

ENM, by Region 

Geographic Area 

Resource Concern 

Sediment 

Sheet 

and 

Rill 

Wind 

** 

Surface 

N 

Subsurface 

N 

Total 

P 

Soluble 

P 

Soil 

Carbon 

National ENM 

Region 

97 93 100 99 77 97 79 87 

Percent Regional Acres 

Atlantic and Gulf 

Coastal Plains 97 91 100 99 47 94 39 83 

California Coastal 99 100 100 100 74 98 86 60 

East Central 91 75 100 97 60 89 39 87 

Lower Mississippi 

and Texas Gulf Coast 91 86 100 98 64 87 26 87 

North Central and 

Midwest 97 90 100 99 75 97 78 88 

Northeast 95 81 100 99 57 88 49 82 

Northern Plains 100 100 100 100 83 100 99 86 

Northwest 99 100 100 100 85 99 95 91 

South Central 88 80 100 94 65 89 55 72 

Southern and Central 

Plains 100 99 100 100 92 100 99 92 

Southwest 97 97 100 100 79 97 94 82 

* The highlighted cells indicate a regional percentage equal to or above the national average. 

** Wind erosion control under ENM reflects the application of structural wind erosion control practices on the 

most susceptible acres, however, these are not widely adopted in the most wind-erosion prone regions where water 

supply challenges the use of vegetative structural practices. CEAP survey data indicate that only 2 percent of acres 

had structural wind erosion control practices applied, highlighting the need for alternative wind erosion control 

methods 

Subsurface nitrogen and soluble phosphorus losses are the most challenging to control, even 

under ENM. While surface losses can be trapped by edge-of-field practices (e.g., filter strips and 

buffers), there are fewer trapping options for subsurface and soluble losses. Treating the cropped 

areas with nutrient management and improved runoff control has limitations, especially in higher 

rainfall regions and with the economic and social priorities for food, feed, fiber, and fuel from 

cropland. Enhanced-efficiency fertilizers and precision agriculture with variable-rate technology 

can help, along with improved timing of nutrient applications. In some cases, however, practices 

such as drainage water management, establishment of wetlands or retention basins, or other 

measures may be needed to prevent losses. 

The percentage of cultivated cropland acres meeting the various thresholds under ENM would 

vary more widely by region for sheet and rill erosion, subsurface nitrogen, soluble phosphorus, 

and soil carbon. In the East Central, South Central, and Northeast regions—with higher 

proportions of rolling to hilly landscapes under cultivation and rainfall above 35 inches—each 

would have 80 percent or less of cultivated cropland meeting the sheet and rill erosion threshold 

under ENM. 

of vegetative structural practices. CEAP survey data indicate that only 2 percent of acres had structural wind erosion control 

practices applied, highlighting the need for alternative wind erosion control methods. 
 

 

Conservation Practices on Cultivated Cropland 91 

For subsurface nitrogen, seven regions would be below the national average of 77 percent and 

three regions (Atlantic and Gulf Coastal Plains, East Central, and Northeast) would have 60 

percent or fewer acres meeting the threshold. Six regions would be below the national average of 

cultivated cropland meeting the soluble phosphorus threshold of 79 percent. The Lower 

Mississippi and Texas Gulf Coastal Plains was the most challenged, with its humid, subtropical 

climate, tile drainage, and rolling hills adjacent to flood plains. 

Acres not meeting thresholds under the substantial conservation modeled in ENM are typically 

on the most vulnerable landscapes and may need additional conservation such as cover crops or 

other changes to the rotation, possibly including perennials, to meet thresholds. 

Comparing Change in Cultivated Cropland Conservation Treatment Levels in 

CEAP Surveys 

Cultivated cropland acres were categorized by conservation treatment levels to allow 

comparisons of change between the two CEAP surveys. The treatment levels were based on the 

number of resource concerns where established loss thresholds were being met. At the high 

treatment level, thresholds were met for all eight resource concerns (sheet and rill erosion, wind 

erosion, sediment, surface nitrogen, subsurface nitrogen, total phosphorus, soluble phosphorus, 

and soil carbon). At the moderate treatment level, thresholds were met for five to seven of the 

resource concerns, and at the low treatment level, thresholds were met for four or fewer resource 

concerns. 

Between the two CEAP surveys, there was no change in the percentage of cultivated cropland in 

each of the treatment levels nationally (table 46), although the mix of resource concern 

thresholds being met could have shifted in some regions. For example, more acres were meeting 

erosion and sediment thresholds in CEAP II, offsetting a decline in acres meeting subsurface 

nitrogen and soluble phosphorus thresholds. At the regional scale, there were a few significant 

changes, most notably in the Northwest, Southwest, and Southern and Central Plains, where 

cultivated cropland with high treatment levels increased by 9 to 14 percent. 

Eight regions had declines in cultivated cropland meeting high treatment levels from CEAP I to 

CEAP II, likely due to a loss in meeting certain nutrient management thresholds. The South 

Central region dropped from 30 percent to 21 percent of acres in high treatment and increased 

from 26 percent to 30 percent in low treatment levels. The East Central region dropped from 19 

percent to 11 percent of acres in high treatment levels, and the Lower Mississippi and Texas Gulf 

Coast had the fewest acres in high treatment, dropping from 11 percent to 9 percent between the 

CEAP surveys. Meeting the high treatment level was challenging in these higher rainfall regions. 

Except for the Northeast, South Central, and Northwest, most regions had little change in the 

percentage of acres with low treatment levels. Most regions showed an increase in the moderate 

treatment level, with seven regions experiencing an increase. Notably, the Northwest and 

Southern and Central Plains had high treatment levels on over 60 percent of cultivated cropland 

by CEAP II. The Northern Plains followed at 56 percent but had declined relative to CEAP I 

levels. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

92 Conservation Effects Assessment Project 

Table 46. Cultivated Cropland by Conservation Treatment Level, CEAP I and CEAP II 

Geographic Scope 

Conservation Treatment Level 

High Moderate Low 

CEAP I CEAP II CEAP I CEAP II CEAP I CEAP II 

Percent 

National 43 43 47 47 10 10 

Region 

Atlantic and Gulf Coastal Plains 15 13 70 73 15 13 

California Coastal 45 40 52 58 3 2 

East Central 19 11 56 63 25 26 

Lower Mississippi and Texas Gulf Coast 13 9 68 72 19 18 

North Central and Midwest 43 40 47 51 10 9 

Northeast 15 15 55 63 30 22 

Northern Plains 58 56 38 36 5 8 

Northwest 47 61 47 36 6 3 

South Central 30 21 44 49 26 30 

Southern and Central Plains 55 64 40 32 5 4 

Southwest 31 44 64 50 6 5 

* The highlighted cells indicate that CEAP II values are higher than CEAP I. 

Comprehensive conservation systems that address all applicable resource concerns can achieve 

significant control of potential losses from farm fields (table 47). The 43 percent of cultivated 

cropland acres with high treatment met thresholds for all eight resource concerns, while the 10 

percent of acres at low treatment met none. Moderate levels of treatment met all but subsurface 

nitrogen and soluble phosphorus thresholds. In fact, the subsurface nitrogen losses of 33 lbs/a/y 

losses were very near that of low treatment (39 lbs/a/y). Soluble phosphorus had an average of 

0.6 lbs/a/y, just barely over the threshold. Both resource concerns, however, had the lowest 

national performance under the ENM treatment at only 77 and 79 percent, respectively, 

indicating the difficulty in controlling these loss pathways. 

Table 47. Losses on Cultivated Cropland by Treatment Level and Resource Concern, CEAP II 

Treatment 

Level 

Percent Cultivated 

Cropland Acres Sediment Subsurface 

N 

Surface 

N 

Total 

P 

Soluble 

P 

Water 

Erosion 

Wind 

Erosion 

Soil 

Carbon 

CEAP I CEAP II tons lbs lbs lbs lbs tons tons lbs 

unit / per acre / per year 

High 43 43 0.2 7.2 3.0 0.5 0.1 0.7 0.9 322.1 

Moderate 47 47 0.5 33.1 5.9 1.7 0.6 1.3 1.8 161.7 

Low 10 10 5.1 39.7 25.8 8.2 1.2 7.5 4.0 -174.1 

Loss Threshold (ac/yr) 2 25 15 3 0.5 Soil T Soil T Gain or 

Maintain 

* The highlighted cells indicate that loss meets the threshold for that resource concern. 

Erosion Control and Nutrient Management Treatment (ENM) Effects by 

Treatment Need 

Simulations that applied ENM to cultivated cropland needing conservation treatment show the 

benefits of conservation systems that address all applicable resource concerns. In CEAP II, over 

30 million acres (10 percent) of cultivated cropland were in the low conservation treatment level 

(meeting thresholds for four or fewer resource concerns) and thus considered high-need acres. 

Moderate-need acres (those meeting thresholds for five to seven resource concerns) accounted 

for another 148.8 million acres (47 percent). 
 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 93 

Treating high-need acres to the ENM level would reduce sediment loss by 44 percent, largely 

through runoff control, which would also reduce surface nitrogen losses by 28 percent and total 

phosphorus losses by 29 percent. As expected, however, this treatment level would reduce 

subsurface nitrogen and soluble phosphorus losses by only 3 and 4 percent, respectively (table 

48). 

Table 48. Estimated Loss Reduction from CEAP II Baseline, by Loss Type and Treatment Level 

Loss Type 

CEAP II 

Baseline Loss 

Treatment Level 

High Need Acres High-and ModerateNeed Acres All Acres 

Tons Percent Reduction 

Sediment 263,455 44 61 67 

Wind Erosion 509,740 22 72 93 

Sheet and Rill Erosion 522,263 17 23 24 

Surface Nitrogen 1,038 28 60 74 

Subsurface Nitrogen 3,550 3 19 21 

Total Phosphorus 283 29 52 58 

Soluble Phosphorus 70 4 13 15 

Soil Carbon 31,381 4 3 0 

Acres in category (1,000s) 30,073 178,855 315,303 

Treating the high- and moderate-need acres to the ENM level would reduce most losses to levels 

near what could be achieved if all acres were treated. For some resource concerns (i.e., sheet and 

rill erosion, subsurface nitrogen, soluble phosphorus, carbon), however, reductions would be 

relatively small. In addition, because the low-need acres (high conservation treatment level) meet 

all resource concern loss thresholds, increased treatment can risk affecting productivity. Both 

results highlight the need for additional measures beyond ENM to increase control of subsurface 

nitrogen and soluble phosphorus losses. 

The reduction in nutrient application rates and attention to application timing and method 

supported by erosion-control practices would result in significant loss reductions in the hightreatment-needs acres (table 49). Sediment, wind erosion, surface nitrogen, total phosphorus, and 

soil carbon would all improve by more than 50 percent. Sheet and rill erosion would be reduced 

by nearly 3 t/a/y—a 39-percent reduction—while the two most difficult resource concerns to 

control, losses of subsurface nitrogen and soluble phosphorus, would be reduced by 16 and 15 

percent, respectively. In addition, estimated average yields of the five most prevalent crops were 

negligibly affected in this treatment simulation. The high-needs acres would see a slight but not 

significant increase in production, while the other treatment groups would experience very small 

decreases. 

Notably, ENM treatment would result in a significant reduction in nitrogen and phosphorus 

applications, producing an associated economic benefit for the farm. Treating the high-need 

acres would reduce nitrogen applied by nearly 16 lbs/a/y and phosphorus by over 5 lbs/a/y. 

Likewise, treating moderate-need acres would reduce nitrogen applied by over 14 lbs/a/y and 

phosphorus by over 4 lbs/a/y. The focused treatment of high- and moderate-needs acres within a 

crop field highlight the economic and environmental opportunities of comprehensive 

conservation planning and precision conservation. 
 

 

 

 

 

 

 

 

 

 

 

 

 

94 Conservation Effects Assessment Project 

Table 49. Estimated Effects of ENM Treatment on Cultivated Cropland by Resource Concern and Treatment 

Need 

Resource Concerns 

Treatment Need 

High Need Moderate Need Low Need 

CEAP II 

Baseline 

As 

Treated 

Change 

from 

CEAP II 

CEAP II 

Baseline 

As 

Treated 

Change 

from 

CEAP II 

CEAP II 

Baseline 

As 

Treated 

Change 

from 

CEAP II 

unit/ac/yr Percent unit/ac/yr Percent unit/ac/yr Percent 

Sediment (tons) 5.1 1.2 -76 0.5 0.2 -55 0.2 0.1 -50 

Sheet and Rill Erosion 

(tons) 7.5 4.6 -39 1.3 1.1 -15 0.7 0.7 -6 

Wind Erosion (tons) 4.0 0.2 -95 1.8 0.1 -93 0.9 0.1 -89 

Surface Nitrogen (lbs.) 25.8 6.5 -75 5.9 1.5 -74 3.0 0.9 -71 

Subsurface Nitrogen 

(lbs.) 39.8 33.3 -16 33.1 25.2 -24 7.2 6.3 -12 

Total Phosphorus (lbs.) 8.2 2.6 -68 1.7 0.8 -52 0.5 0.3 -49 

Soluble Phosphorus 

(lbs.) 1.2 1.0 -15 0.6 0.5 -15 0.1 0.1 -17 

Soil Carbon (tons) -174.2 -82.0 -53 161.7 154.7 -4 322.2 308.7 -4 

Estimated Input Effect (lbs/a/y) 

Nitrogen Applied (lbs.) 92.7 76.7 -17 89.0 74.5 -16 63.4 58.7 -7 

Phosphorus Applied 

(lbs.) 24.2 18.6 -23 21.3 17.0 -20 15.1 14.0 -7 

Estimated Yield Effect (bu/a/y) 

Corn (Grain) 158.3 158.8 0.3 159.5 158.1 -0.9 158.3 155.8 -1.6 

Cotton 912.9 914.0 0.1 888.9 877.7 -1.3 896.8 883.2 -1.5 

Durum & Spring Wheat 54.9 54.9 0.1 53.1 52.7 -0.7 48.7 48.6 -0.2 

Soybeans 43.8 43.9 0.2 42.9 42.6 -0.8 43.9 43.5 -0.7 

Winter Wheat 59.8 60.2 0.7 56.7 55.5 -2.1 42.3 42.2 -0.1 

How Did Conservation in CEAP I and CEAP II Compare to ENM? 

The conservation measures in place by CEAP II delivered progress toward the simulated ENM 

treatment level for most resource concerns (table 50). By CEAP II, sediment and sheet and rill 

erosion losses were at 80 and 84 percent of the simulated ENM treatment level, both with 

increases over the decade. While surface and subsurface nitrogen and sediment-transported 

phosphorus were at 61, 67, and 65 percent of their respective ENM treatment levels, subsurface 

nitrogen losses had increased since CEAP I. In CEAP II, soluble phosphorus losses were at 54 

percent of ENM treatment level, down significantly from CEAP I. Wind erosion, while only at 

42 percent of its ENM treatment level, nevertheless had the greatest progress toward ENM 

between the two CEAP surveys. 
 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 95 

Table 50. Progress toward ENM by Resource Concern, CEAP I and CEAP II 

Resource Concern 

Treatment Level 

CEAP 

II 

minus 

CEAP 

I 

Change in 

Tons 

Relative to 

CEAP I 

Progress toward ENM 

No 

Practice 

(NP) 

Erosion 

Control and 

Nutrient 

Management 

(ENM) 

CEAP 

I 

CEAP 

II 

CEAP 

I 

CEAP 

II 

CEAP 

II 

minus 

CEAP I 

Average Annual Tons (1,000s) Percent 

Sheet & Rill Erosion (Losses) 1,197,255 398,231 598,623 522,263 76,360 13 75 84 9 

Wind Erosion (Losses) 848,310 37,024 603,605 509,740 93,865 16 30 42 12 

Sediment (Losses) 946,467 87,834 337,635 263,455 74,181 22 71 80 11 

Surface N (Losses) 2,218 272 1,073 1,038 -35 -3 59 61 2 

Subsurface N (Losses) 5,095 2,803 3,130 3,550 420 13 86 67 -18 

Total P (Losses) 592 118 290 283 -7 -2 64 65 1 

Soluble Phosphorus (Losses) 83 59 63 70 7 11 85 54 -31 

Soil Carbon (Gains) 6,823 31,320 22,519 31,381 8,862 39 64 100 36 

Erosion and Sediment 

With the increase in conservation tillage, structural practices, cover crops, and high-biomass 

conservation crop rotations between the CEAP surveys, there was significant progress toward 

ENM for sheet and rill erosion, wind erosion, and sediment. In CEAP II, annual sheet and rill 

erosion was about 84 percent of ENM, up from 75 percent in CEAP I (fig. 60). Sediment was at 

80 percent of ENM in CEAP II, up from 71 percent in CEAP I. Although progress for wind 

erosion was only 42 percent of ENM in CEAP II, it was up from 30 percent in CEAP I. The 

lower performance level reflects that much of the current toolbox for wind erosion control 

depends on vegetative practices that are typically less well suited to the most wind-erosion-prone 

areas of the Nation. 

Two regions—North Central and Midwest and Southern and Central Plains—were above the 

average national progress toward the sheet and rill ENM, at 90 percent and 86 percent, 

respectively. The Northern Plains region led progress toward the wind erosion ENM at 58 

percent, 16 percentage points above the national average. Progress toward the sediment ENM 

mirrored sheet and rill erosion, with the North Central and Midwest and Southern and Central 

Plains regions being above the national average, at 86 percent and 81 percent respectively (fig. 

61). 
96 Conservation Effects Assessment Project 

Figure 60. Erosion and Sediment Progress Toward ENM, CEAP I and CEAP II 

Figure 61. Progress toward Erosion and Sediment ENM by Loss Pathway and Region, CEAP II 
 

 

Conservation Practices on Cultivated Cropland 97 

Nitrogen 

Progress toward ENM for the nitrogen-related resource concerns was mixed, reflecting the 

increase in conservation measures that controlled runoff and the general decline in nutrient 

management practices between the CEAP surveys (fig. 62). The surface nitrogen resource 

concern was at 61 percent of ENM performance in CEAP II, up only slightly from 59 percent in 

CEAP I. However, it was the only nitrogen loss pathway that increased in progress toward ENM 

treatment level between the two survey periods. Control of subsurface nitrogen losses 

experienced a significant decline in progress toward ENM, dropping from 86 percent in CEAP I 

to 67 percent in CEAP II, consistent with the decline in nutrient management practices, 

particularly the decline in nutrient incorporation. 

Figure 62. Surface and Subsurface Nitrogen Progress Toward ENM, CEAP I and CEAP II 

Over the decade between surveys, five of the 11 regions had increases in total nitrogen losses, 

led by the Northern Plains with a 49-percent increase, followed by the East Central (32 percent) 

and North Central and Midwest (13 percent). Two regions—the North Central and Midwest and 

Northern Plains—had the greatest increase in nitrogen losses, but also had progress toward ENM 

above the 64-percent national average, at 70 and 67 percent, respectively. 

Progress toward the surface nitrogen ENM was led by the North Central and Midwest and East 

Central regions, at 74-percent and 64-percent progress, respectively. The Northern Plains region 

led progress toward the subsurface ENM at 84 percent, 16 percentage points above the national 

average. Only two regions (Northwest and South Central) performed better in CEAP II than 

CEAP I relative to the ENM for all three measures (fig. 63). 
 

 

 

98 Conservation Effects Assessment Project 

Figure 63. Progress toward Nitrogen ENM by Loss Pathway and Region, CEAP II 

Phosphorus 

Like nitrogen, phosphorus resource concerns also experienced mixed progress toward ENM, 

reflecting the change in conservation adoption over the decade (fig. 64). The total phosphorus 

resource concern made progress, reaching 65 percent of ENM by CEAP II, up from 64 percent in 

CEAP I. In contrast, soluble phosphorus progress toward ENM was at 54 percent in CEAP II, 

down from 85 percent in CEAP I and experiencing the largest percentage decline of all resource 

concerns, reflecting increased application rates and the declines in nutrient incorporation. The 

progress for total phosphorus was affected by the soluble decline, tempering its performance. In 

comparison, for sediment-transported phosphorus (discussed elsewhere in the report) progress 

toward ENM increased from 63 percent to 66 percent in CEAP I and CEAP II, respectively. 

Figure 64. Total and Soluble Phosphorus Progress toward ENM, CEAP I and CEAP II 

Nearly every region gained in progress toward the total phosphorus ENM between the two 

surveys, while only one region—North Central and Midwest—was above the average national 

progress. The North Central and Midwest was also the only region above the national average for 

the sediment-transported ENM, at 74 percent, the same as the region’s CEAP I progress. The 
 

 

 

 

Conservation Practices on Cultivated Cropland 99 

California Coastal and Lower Mississippi and Texas Gulf Coast regions led progress toward the 

soluble phosphorus ENM at 77 and 73 percent, respectively (fig. 65). 

Figure 65. Progress toward Phosphorus ENM by Loss Pathway and Region, CEAP II 

Soil Carbon 

Soil carbon is evaluated in terms of carbon maintained or gained rather than a reduction in 

losses. In CEAP II, soil carbon was the only resource concern achieving 100 percent of the ENM 

treatment level, up from 64 percent in CEAP I and reflecting the significant increase in 

conservation tillage and structural practices that retained organic matter on farm fields (fig. 66). 

With the ENM treatment, the reduced nutrient application rate may result in lower biomass 

production on some acres and lower the net change in carbon. In a comprehensive plan, soil 

carbon may not be able to be maximized on all acres if other resource concerns such as water 

quality are priorities. 

Figure 66. Soil Carbon Progress toward ENM, CEAP I and CEAP II 
 

 

100 Conservation Effects Assessment Project 

All but one region (South Central) gained in progress toward the soil carbon ENM between the 

two surveys, and four regions—Atlantic and Gulf Coastal Plains, East Central, North Central and 

Midwest, and Northeast—were above the national average of 100 percent. Although progress in 

the drier regions of California Coastal and Southwest trailed other regions, each had among the 

largest increases between the survey periods at 163 and 155 percent, respectively (fig. 67). 

Figure 67. Progress toward Soil Carbon ENM by Region, CEAP II 

Summary 

Between the CEAP surveys, most resource concerns made progress toward ENM performance 

levels with two notable exceptions—subsurface nitrogen and soluble phosphorus. Both resource 

concerns experienced the effects of a decline in nutrient management practices, in some areas 

amplified by the adoption of conservation practices that managed runoff and related losses but 

promoted infiltration and soluble losses. Nevertheless, despite setbacks in CEAP II, all but two 

of the eight resource concerns were at 60 percent or more of their respective ENM levels. One of 

the two with lower performance, wind erosion, faces challenges related to the scant toolbox for 

controlling the loss pathway. Also, all but two resource concerns had moved closer to ENM 

levels between the CEAP surveys. The decline in subsurface nitrogen and soluble phosphorus 

resource concerns underscores the importance of conservation planning that considers all 

applicable resource concerns to build on progress and prevent unintended consequences. 
Conservation Practices on Cultivated Cropland 101 

SUMMARY AND AGENCY ACTIONS 

The CEAP II report (2013–16) reveals progress from the time of the first CEAP report (2003– 

06) in addressing resource concerns such as sediment loss, soil erosion, and water use. Farmer 

adoption of structural practices and conservation tillage, alone or in combination, increased by 

nearly 42 million acres nationwide between the two CEAP surveys. The greatest gains were 

made in the adoption of structural practices plus conservation tillage, evidence that farmers were 

increasingly integrating multiple conservation treatments to achieve improved results. As a 

result, sheet and rill erosion dropped by nearly 70 million tons per year (an 11-percent reduction 

relative to CEAP I) and wind erosion dropped by 94 million tons per year (a 15-percent 

reduction relative to CEAP I). Irrigators gained efficiencies, reducing per-acre application rates 

and national withdrawals over the decade. 

However, the new findings also indicate some declines in nutrient management levels on 

working lands. Changes in commodity prices, climate factors, and evolving technology have 

driven shifts in cropping patterns in many areas toward corn and soybeans and away from wheat. 

Corn and soybeans have significantly higher average nutrient needs than wheat, explaining some 

of the increase in nutrient application rates between the CEAP surveys. Nutrient incorporation 

declined, and consequently the shifts in rate, timing, and method of nutrient application resulted 

in overall increases in subsurface nitrogen and soluble phosphorus losses over the decade. 

Without attention to appropriate timing and method, increased application rates are less effective 

in improving production and may even lead to reduced yields. While most cultivated cropland 

acres met the various soil and nutrient loss thresholds in both survey periods, most of the related 

material losses come from the small number of cultivated cropland acres that exceeded those loss 

thresholds. 

Since 2016, NRCS has made considerable strides in addressing key resource challenges as 

presented in this report. In addition, the agency has developed new tools, such as the 

Conservation Assessment Ranking Tool and Conservation Desktop, and implemented new 

initiatives and program opportunities, including the National Water Quality Initiative, and 

Regional Conservation Partnership Program. 

In response to these new CEAP II findings, and building upon post-2016 progress, NRCS has 

renewed its focus on proper nutrient and manure management, as well as an agencywide 

commitment to targeted solutions to further improve the Nation’s water quality. NRCS formed 

interdisciplinary teams to develop recommendations and assist with the agency’s strategy for 

integrating CEAP II findings into policies, programs, and targeted initiatives that will result in 

greater conservation outcomes. Each team focused on a core discipline: conservation planning 

and program implementation, technical infrastructure, future resource assessment, and policy. 
102 Conservation Effects Assessment Project 

The four overarching goals of our evolving nutrient management strategy are: developing a 

nutrient management campaign to educate and engage partners; revitalizing the agency’s nutrient 

management planning and implementation processes; focusing technical assistance on integrated 

conservation planning; and enhancing program implementation with a nutrient management 

focus. Each overarching goal contains a set of specific recommendations that will help NRCS 

and producers continue to adapt nutrient management to national changes in markets, trade, 

climate, and cropping systems. 
 

 

 

Conservation Practices on Cultivated Cropland 103 

APPENDIX 1. OVERVIEW OF THE CEAP SAMPLING AND MODELING 

APPROACH 

The CEAP Cropland National Assessment is a collaborative effort led by NRCS in partnership 

with USDA's Agricultural Research Service and Texas A&M University’s Texas Agri-Life 

Research Center in Temple, TX. In addition, USDA's National Agricultural Statistics Service 

and Farm Service Agency provide important data collection and related contributions. 

CEAP uses a sampling and modeling approach that integrates natural resource and farmer survey 

data with modeling to quantify the effects of commonly used conservation practices on 

cultivated cropland. CEAP defines cultivated cropland as land in row crops or close-grown 

crops, hay and pasture in rotation with row crops and close-grown crops, and land in long-term 

conserving cover, such as land enrolled in the Conservation Reserve Program general signup. 

Cultivated cropland does not include agricultural land that has been in hay, pasture, or 

horticulture for four or more consecutive years. 

CEAP Statistical Sampling and Modeling Approach to Simulate Conservation Practice 

Effects 

The CEAP Cropland sampling and modeling approach captures the diversity of land use, soils, 

climate, and topography; accounts for site-specific farming activities; estimates the loss of 

materials at the field scale where the science is most developed; and provides a statistical basis 

for aggregating results to the national and regional levels. The approach consists of four 

components: 

● Sampling – A subset of National Resources Inventory (NRI) sample points serves as 

“representative fields.” These NRI sample points, which are located on cultivated cropland 

and land in long-term conserving cover, provide the statistical framework for the model as 

well as information on soils, climate, and topography. Nationally, the CEAP sample consists 

of about 18,700 points representing cropped acres. The CEAP sample was designed to allow 

reporting of results at a 4-digit watershed scale (4-digit hydrologic unit code [HUCs]). The 
 

 

 

 

104 Conservation Effects Assessment Project 

sample size is too small, in most cases, for reliable and defensible reporting of results for 

areas below this level. CEAP cropland modeling results are reported as estimates because of 

the uncertainty associated with the statistical sample. 

● Farmer Surveys – The CEAP Cropland Farmer Surveys are used to collect information 

needed at the selected NRI sample points to run field-level models and assess the effects of 

conservation practices. NASS partners with state departments of agriculture to interview 

farmers to obtain current information on farming practices, including: 

o field characteristics, such as proximity to a water body or wetland and presence of tile 

or surface drainage systems; 

o conservation practices associated with the field; 

o crop rotation plan; 

o application of commercial fertilizers (rate, timing, method, and form) for crops grown 

in the previous 3 years; 

o application of manure (source and type, consistency, application rate, method, and 

timing) on the field over the previous 3 years; 

o application of pesticides (chemical, rate, timing, and method) for the previous 3 

years; 

o pest management practices; 

o irrigation practices (system type, amount, and frequency); 

o timing and equipment used for all field operations (tillage, planting, cultivation, 

harvesting) over the previous 3 years, and; 

o general characteristics of the operator and the operation. 

Farmer participation is voluntary, and the information is confidential. Because of the large 

size of the sample, the data collection process occurs over multiple years, from 2003 through 

2006 for CEAP I and 2013 through 2016 for CEAP II. 30 The final CEAP samples for each 

survey period were constructed by pooling the set of usable, completed surveys from all 

years. 

● The Physical Process Model – The Agricultural Policy Environmental Extender (APEX) is 

used to assess the field-level effects of conservation practices. APEX simulates day-to-day 

farming activities, wind and water erosion, the loss or gain of soil organic carbon, and edgeof-field losses of soil, nutrients, and pesticides. 

● Watershed Model and System of Databases – The Soil and Water Assessment Tool / 

Hydrologic Unit Model of the United States (SWAT/HUMUS) is used to simulate the 

transport of edge-of-field losses (APEX model output) to receiving streams and routes 

instream loads from one watershed to another. SWAT/HUMUS allows estimation of the 

changes in in-stream concentrations of sediment, nutrients, and pesticides attributable to 

conservation practice implementation. 

30 The surveys, the enumerator instructions, and other documentation can be found at 

https://www.nrcs.usda.gov/ceap/croplands
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 105 

The modeling strategy for estimating the effects of conservation practices consists of model 

scenarios that are produced for each sample point. The effects of conservation practices are 

obtained by taking the difference in model results between the various scenarios.31 For example, 

to simulate “no practices” for sample points with structural and annual conservation practices 

(buffers, terraces, grassed waterways, conservation tillage, nutrient management, etc.), model 

simulations were conducted as if the practices were not present and compared to the results with 

the practices in place to estimate the change. Multiple alternative treatment scenarios were 

developed for analysis, including: 

1. No Practice – simulates model results as if no conservation practices were in use but holds all other 

model inputs and parameters the same as in the current conservation condition scenario (e.g., CEAP 

I). 

2. CEAP I and CEAP II – simulates model results that account for cropping patterns, farming activities, 

and conservation practices as reported in the CEAP Cropland Surveys and other sources for each 

survey period (CEAP I, 2003–06, and CEAP II, 2013–16). 

3. Erosion Control (EC) – simulates model results associated with conservation practices designed to 

control and trap soil losses from cropped fields primarily through additions of structural conservation 

practices. Tillage practices are not altered. 

4. Nutrient Management (NM) – simulates model results related to conservation practices designed to 

avoid excess surface and subsurface nutrient losses through adjustments to nutrient application 

method, timing, and rate. A 10-percent reduction in nutrient application rate is used in this scenario.32 

Nutrient form is not adjusted as it may relate to decision factors not in the survey such as equipment 

or the need to use manure from the operation. 

5. Erosion Control and Nutrient Management (ENM) – simulates model results reflecting a 

comprehensive conservation plan by combining the EC and NM scenarios with additional 

improvements to structural conservation practices and nutrient management. 

6. Erosion Control and Nutrient Management 85 (ENM85) – simulates erosion control and nutrient 

management but with only 85 percent of the nutrient form being applied and with additional 

improvements to nutrient timing and incorporation and runoff controls to improve nutrient-use 

efficiency. 

Technical information on the CEAP Cropland methodology studies, including documentation 

reports on the modeling methodology, models and databases are available on the Web as part of 

the CEAP Croplands Assessments.

33 

31 This modeling strategy is similar to NRI estimates of soil erosion and the intrinsic erosion rate used to identify highly erodible

land. The NRI uses the Universal Soil Loss Equation (USLE) to estimate sheet and rill erosion at each sample point based on sitespecific factors. Soil loss per unit area is equal to R*K*L*S*C*P. The first four factors—R, K, L, S—represent the conditions of 

climate, soil, and topography existing at a site. The last two factors—C and P—represent the degree to which management 

influences the erosion rate. The product of the first four factors is sometimes called the intrinsic, or potential, erosion rate. The 

intrinsic erosion rate divided by T, the soil loss tolerance factor, produces estimates of the erodibility index. The intrinsic 

erosion rate is thus a “no-practice” representation of sheet and rill erosion since C=1 represents smooth-tilled continuous 

fallow and P=1 represents no supporting practices. 

32 The 10-percent reduction was selected as a level where productivity is maintained on most soils while demonstrating the

effects of improved use efficiency that is provided through rate reductions in combination with improved timing and 

application methods, particularly in precision agriculture systems. 

33https://www.nrcs.usda.gov/ceap/croplands 
106 Conservation Effects Assessment Project 

APPENDIX 2. REGIONAL TABLES 

Table A-1. Cultivated Cropland Acreage by Region, CEAP I and CEAP II........................................................................................ 107 

Table A-2. Harvested Crops, Top Five by Acreage, National and by Region, CEAP I and CEAP II...................................................108 

Table A-3. Cultivated Cropland by Treatment Group by Region, CEAP I and CEAP II.....................................................................110 

Table A-4. Structural Practice Adoption by Region, CEAP I and CEAP II.........................................................................................111 

Table A-5. Structural Practice Groups by Region, CEAP I and CEAP II............................................................................................112 

Table A-6. Tillage Groups by Region, CEAP I and CEAP II...............................................................................................................114 

Table A-7. Highly Erodible Land (HEL) Cultivated Cropland by Treatment Group and Region, CEAP I and CEAP II .......................115 

Table A-8. Cultivated Cropland with High and Moderately High Runoff (SVI) ratings by Treatment Group and Region, CEAP I and 

CEAP II ...........................................................................................................................................................................................117 

Table A-9. Conservation Crop Rotations by Group and Region, CEAP II ........................................................................................123 

Table A-10. Nitrogen Application by Incorporation and Region, CEAP I and CEAP II.....................................................................126 

Table A-11. Phosphorus Application by Incorporation and Region, CEAP I and CEAP II ................................................................127 

Table A-12. Nitrogen Application Timing and Incorporation by Region, CEAP I and CEAP II.........................................................128 

Table A-13. Phosphorus Application Timing and Incorporation by Region, CEAP I and CEAP II ....................................................131 

Table A-14. Sheet and Rill Erosion Relative to Threshold by Region, CEAP I and CEAP II...............................................................134 

Table A-15. Wind Erosion Relative to Threshold by Region, CEAP I and CEAP II............................................................................135 

Table A-16. Sediment Relative to Threshold by Region, CEAP I and CEAP II..................................................................................136 

Table A-17. Surface Nitrogen Relative to Threshold by Region, CEAP I and CEAP II......................................................................137 

Table A-18. Sediment Transported Phosphorus Relative to Threshold by Region, CEAP I and CEAP II..........................................138 

Table A-19. Subsurface Nitrogen Relative to Threshold, CEAP I and CEAP II .................................................................................139 

Table A-20. Soluble Phosphorus Relative to Threshold by Region, CEAP I and CEAP II..................................................................140 

Table A-21. Soil Carbon Relative to Threshold by Region, CEAP I and CEAP II...............................................................................141 

Table A-22. Sediment Management on Cultivated Cropland by Region, CEAP I and CEAP II ........................................................142 

Table A-23. Nitrogen Management on Cultivated Cropland by Region, CEAP I and CEAP II .........................................................143 

Table A-24. Phosphorus Management on Cultivated Cropland by Region, CEAP I and CEAP II.....................................................144 

Table A-25. Sediment Management and Soil Vulnerability Index – Runoff (SVI-R) by Region, CEAP I and CEAP II .......................145 

Table A-26. Nitrogen Management and Soil Vulnerability Index – Leaching (SVI-L) by Region, CEAP I and CEAP II .....................151 

Table A-27. Phosphorus Management and Soil Vulnerability Index – Runoff (SVI-R) by Region, CEAP I and CEAP II.................... 157 
 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 107 

Table A-1. Cultivated Cropland Acreage by Region, CEAP I and CEAP II 

Production Region 

CEAP I CEAP II CEAP II minus CEAP 

I 

Acre 

Change 

Relative 

to CEAP I 

Acres 

(1,000s) Percent Acres (1,000s) Percent Acres (1,000s) Percent Percent 

Atlantic and Gulf Coastal 

Plains 14,395 5 13,825 4 -570 0 -4 

California Coastal 4,447 1 3,913 1 -534 0 -12 

East Central 9,312 3 10,166 3 854 0 9 

Lower Mississippi and 

Texas Gulf Coast 21,816 7 20,916 7 -900 0 -4 

North Central and 

Midwest 120,134 38 123,296 39 3,162 1 3 

Northeast 7,190 2 7,597 2 407 0 6 

Northern Plains 48,420 15 51,130 16 2,710 1 6 

Northwest 14,010 4 13,438 4 -571 0 -4 

South Central 6,135 2 5,107 2 -1,027 0 -17 

Southern and Central 

Plains 64,337 21 62,732 20 -1,605 -1 -2 

Southwest 2,870 1 3,183 1 313 0 11 

National 313,065 315,303 2,238 1 
 

 

 

 

 

 

 

108 Conservation Effects Assessment Project 

Table A-2. Harvested Crops, Top Five by Acreage, National and by Region, CEAP I and CEAP II 

Region 

CEAP I CEAP II 

Crop Harvested Acres Count Crop Harvested Acres Count (1,000s) (percent) (1,000s) (percent) 

National 

Soybean 81,563 26 11,011 Soybean 92,275 29 7,250 

Corn 79,186 25 10,445 Corn 89,963 29 6,691 

Winter Wheat 45,528 15 4,361 Winter Wheat 43,258 14 2,871 

Idle/Fallow 20,648 7 2,031 Idle/Fallow 16,794 5 1,070 

Durum & 

Spring Wheat 19,030 6 1,290 

Durum & 

Spring Wheat 15,570 5 765 

Atlantic and Gulf Coastal Plains 

Cotton 4,087 28 422 Soybean 4,366 32 498 

Soybean 3,822 27 821 Cotton 3,083 22 223 

Corn 2,740 19 664 Corn 2,446 18 330 

Peanuts 1,433 10 196 Winter Wheat 2,030 15 247 

Winter Wheat 1,099 8 288 Peanuts 1,807 13 156 

California Coastal 

Vegetable 906 20 28 Rice 942 24 51 

Cotton 887 20 11 Vegetable 863 22 57 

Rice 814 18 38 Winter Wheat 636 16 39 

Corn Silage 520 12 8 Corn Silage 509 13 32 

Idle/Fallow 436 10 20 Alfalfa/Clover 263 7 18 

East Central 

Soybean 3,602 39 642 Soybean 4,621 45 582 

Corn 2,862 31 601 Corn 3,582 35 480 

Winter Wheat 1,140 12 190 Winter Wheat 1,649 16 218 

Cotton 654 7 84 Corn Silage 389 4 43 

Corn Silage 582 6 80 Close grown 371 4 47 

Lower Mississippi and Texas Gulf Coast 

Soybean 8,776 40 1,183 Soybean 9,740 47 1015 

Cotton 4,762 22 464 Corn 3,099 15 446 

Rice 2,921 13 430 Rice 2,843 14 308 

Corn 2,323 11 497 Cotton 1,745 8 180 

Idle/Fallow 1,121 5 170 Idle/Fallow 997 5 128 

North Central and Midwest 

Corn 53,893 45 6,925 Corn 58,295 47 3,750 

Soybean 52,460 44 7,015 Soybean 52,404 43 3,623 

Winter Wheat 3,965 3 874 Winter Wheat 4,687 4 410 

Alfalfa/Clover 3,211 3 357 Alfalfa/Clover 3,530 3 138 

Corn Silage 2,533 2 300 Close grown 2,448 2 177 

Northeast 

Corn 2,450 34 555 Corn 2,351 31 413 

Corn Silage 1,405 20 273 Soybean 2,022 27 382 

Soybean 1,354 19 393 Corn Silage 1,288 17 163 

Alfalfa/Clover 509 7 101 Winter Wheat 1,000 13 190 

Winter Wheat 498 7 172 Alfalfa/Clover 864 11 101 

Northern Plains 

Durum & 

Spring Wheat 15,806 33 922 Durum & Spring Wheat 12,990 25 587 

Soybean 7,214 15 507 Soybean 12,463 24 599 

Idle/Fallow 5,827 12 384 Corn 7,784 15 452 

Corn 4,678 10 371 Idle/Fallow 3,839 8 190 

Winter Wheat 3,351 7 228 Winter Wheat 3,698 7 192 
 

 

 

 

Conservation Practices on Cultivated Cropland 109 

Table A-2. Harvested Crops, Top Five by Acreage, National and by Region, CEAP I and CEAP II—Cont. 

Region 

CEAP I CEAP II 

Crop Harvested Acres Count Crop Harvested Acres Count (1,000s) (percent) (1,000s) (percent) 

Northwest 

Winter Wheat 3,917 28 537 Winter Wheat 4,133 31 314 

Idle/Fallow 2,758 20 382 Idle/Fallow 2,623 20 192 

Barley 1,610 11 251 Durum & 

Spring Wheat 1,406 10 112 

Durum & 

Spring Wheat 1,452 10 203 Alfalfa/Clover 985 7 82 

Alfalfa/Clover 827 6 77 Barley 826 6 103 

South Central 

Winter Wheat 1,831 30 118 Winter Wheat 1,243 24 114 

Corn 1,127 18 83 Soybean 1,242 24 120 

Soybean 1,080 18 112 Corn 1,217 24 104 

Sorghum 740 12 47 Sorghum 400 8 47 

Oats 502 8 14 Cotton 361 7 33 

Southern and Central Plains 

Winter Wheat 28,005 44 1,667 Winter Wheat 22,609 36 969 

Idle/Fallow 8,719 14 733 Corn 10,582 17 621 

Corn 8,500 13 656 Cotton 8,479 14 296 

Cotton 6,712 10 427 Idle/Fallow 7,134 11 372 

Sorghum 5,388 8 409 Soybean 5,418 9 431 

Southwest 

Cotton 534 19 64 Alfalfa/Clover 614 19 27 

Winter Wheat 448 16 66 Winter Wheat 593 19 35 

Vegetable 430 15 24 Cotton 500 16 31 

Alfalfa/Clover 324 11 29 Vegetable 346 11 21 

Idle/Fallow 281 10 48 Idle/Fallow 332 10 27 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

110 Conservation Effects Assessment Project 

Table A-3. Cultivated Cropland by Treatment Group by Region, CEAP I and CEAP II 

Treatment Group and Region 

CEAP I CEAP II 

Acres (1,000s) Percent 

Regional Acres Acres (1,000s) Percent Regional Acres 

Structural Practices plus Conservation Tillage 

Atlantic and Gulf Coastal Plains 2,157 15 2,934 21 

California Coastal 481*** 11*** 77*** 2*** 

East Central 3,015 32 4,181 41 

Lower Mississippi and Texas Gulf Coast 2,127 10 3,017 14 

North Central and Midwest 38,854 32 58,046 47 

Northeast 1,295 18 2,882 38 

Northern Plains 7,588 16 13,027 25 

Northwest 1,259 9 3,425 25 

South Central 704*** 11*** 1,167 23 

Southern and Central Plains 7,279 11 18,657 30 

Southwest 100*** 3*** 76*** 2*** 

National 64,860 21 107,489 34 

Structural Practices Only 

Atlantic and Gulf Coastal Plains 1,747 12 2,210 16 

California Coastal 239*** 5*** 772 20 

East Central 1,532 16 640 6 

Lower Mississippi and Texas Gulf Coast 1,885 9 3,384 16 

North Central and Midwest 17,577 15 15,720 13 

Northeast 1,751 24 1,125 15 

Northern Plains 4,720 10 4,559 9 

Northwest 1,804 13 2,396 18 

South Central 1,786 29 1,383 27 

Southern and Central Plains 21,521 33 10,819 17 

Southwest 727*** 25*** 616*** 19*** 

National 55,289 18 43,623 14 

Conservation Tillage Only 

Atlantic and Gulf Coastal Plains 5,189 36 5,169 37 

California Coastal 373*** 8*** 507*** 13*** 

East Central 3,654 39 4,612 45 

Lower Mississippi and Texas Gulf Coast 7,551 35 5,874 28 

North Central and Midwest 35,306 29 32,598 26 

Northeast 1,514 21 1,977 26 

Northern Plains 22,994 47 25,314 50 

Northwest 2,754 20 3,679 27 

South Central 858 14 1,220 24 

Southern and Central Plains 11,787 18 21,546 34 

Southwest 283*** 10*** 546*** 17*** 

National 92,265 29 103,042 33 

No Structural Practices or Conservation 

Tillage 

Atlantic and Gulf Coastal Plains 5,302 37 3,512 25 

California Coastal 3,353 75 2,557 65 

East Central 1,111 12 733 7 

Lower Mississippi and Texas Gulf Coast 10,252 47 8,641 41 

North Central and Midwest 28,396 24 16,931 14 

Northeast 2,630 37 1,614 21 

Northern Plains 13,117 27 8,230 16 

Northwest 8,193 58 3,938 29 

South Central 2,787 45 1,337 26 

Southern and Central Plains 23,750 37 11,711 19 

Southwest 1,760 61 1,944 61 

National 100,651 32 61,148 19 

*** Too few acres for significance change analysis 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 111 

Table A-4. Structural Practice Adoption by Region, CEAP I and CEAP II 

Region 

CEAP I CEAP II 

Acres (1,000s) 

Percent 

Regional 

Acres 

Acres (1,000s) 

Percent 

Regional 

Acres 

One Or More Structural Practices 

Atlantic and Gulf Coastal Plains 3,904 27 5,144 37 

California Coastal 721*** 16*** 849 22 

East Central 4,547 49 4,821 47 

Lower Mississippi and Texas Gulf Coast 4,013 18 6,401 31 

North Central and Midwest 56,431 47 73,766 60 

Northeast 3,046 42 4,007 53 

Northern Plains 12,309 25 17,586 34 

Northwest 3,063 22 5,821 43 

South Central 2,489 41 2,550 50 

Southern and Central Plains 28,799 45 29,475 47 

Southwest 827 29 692*** 22*** 

National 120,149 38 151,113 48 

More Than One Structural Practice 

Atlantic and Gulf Coastal Plains 1,827 13 2,362 17 

California Coastal 577*** 13*** 363*** 9*** 

East Central 1,930 21 2,236 22 

Lower Mississippi and Texas Gulf Coast 972 4 2,234 11 

North Central and Midwest 24,095 20 39,819 32 

Northeast 1,191 17 2,315 30 

Northern Plains 2,012 4 4,224 8 

Northwest 715 5 2,026 15 

South Central 1,318 21 1,571 31 

Southern and Central Plains 16,961 26 18,181 29 

Southwest 66*** 2*** 163*** 5*** 

National 51,664 17 75,494 24 

One Structural Practice 

Atlantic and Gulf Coastal Plains 2,076 14 2,782 20 

California Coastal 143*** 3*** 486*** 12*** 

East Central 2,617 28 2,584 25 

Lower Mississippi and Texas Gulf Coast 3,041 14 4,167 20 

North Central and Midwest 32,336 27 33,947 28 

Northeast 1,856 26 1,691 22 

Northern Plains 10,297 21 13,362 26 

Northwest 2,348 17 3,795 28 

South Central 1,171 19 979 19 

Southern and Central Plains 11,839 18 11,295 18 

Southwest 761*** 27*** 529*** 17*** 

National 68,485 22 75,619 24 

No Structural Practices 

Atlantic and Gulf Coastal Plains 10,491 73 8,681 63 

California Coastal 3,726 84 3,064 78 

East Central 4,766 51 5,345 53 

Lower Mississippi and Texas Gulf Coast 17,803 82 14,515 69 

North Central and Midwest 63,702 53 49,529 40 

Northeast 4,144 58 3,590 47 

Northern Plains 36,111 75 33,544 66 

Northwest 10,947 78 7,617 57 

South Central 3,645 59 2,557 50 

Southern and Central Plains 35,537 55 33,256 53 

Southwest 2,043 71 2,491 78 

National 192,916 62 164,190 52 

*** Too few acres for significance change analysis 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

112 Conservation Effects Assessment Project 

Table A-5. Structural Practice Groups by Region, CEAP I and CEAP II 

Region/Structural Practice Groups 

CEAP I CEAP II 

Acres (1,000s) 

Percent 

Regional 

Acres 

Count Acres 

(1,000s) 

Percent 

Regional 

Acres 

Count 

Atlantic and Gulf Coastal Plains 

Overland Flow Control 1,925 13 126 2,375 17 117 

Concentrated Flow Control 1,777 12 129 1,516 11 90 

Edge of Field Buffering and Filtering 817 6 101 1,408 10 98 

Field Border 1,123 8 81 1,857 13 121 

Wind Erosion Control 309*** 2*** 25 631 5 43 

California Coastal 

Overland Flow Control 557*** 13*** 4 397*** 10*** 18 

Concentrated Flow Control 122*** 3*** 3 185*** 5*** 10 

Edge of Field Buffering and Filtering 481*** 11*** 1 248*** 6*** 16 

Field Border 50*** 1*** 3 358*** 9*** 24 

Wind Erosion Control 38*** 1*** 2 66*** 2*** 6 

East Central 

Overland Flow Control 2,209 24 202 2,001 20 153 

Concentrated Flow Control 2,421 26 245 2,297 23 167 

Edge of Field Buffering and Filtering 839 9 77 1,119 11 85 

Field Border 1,134 12 89 1,644 16 132 

Wind Erosion Control 162*** 2*** 13 479 5 37 

Lower Mississippi and Texas Gulf 

Overland Flow Control 963 4 117 2,146 10 165 

Concentrated Flow Control 2,677 12 267 2,749 13 202 

Edge of Field Buffering and Filtering 641 3 61 948 5 74 

Field Border 484 2 42 2,957 14 184 

Wind Erosion Control 154*** 1*** 9 505 2 37 

North Central and Midwest 

Overland Flow Control 26,101 22 1,812 30,322 25 1,061 

Concentrated Flow Control 34,268 29 2,338 46,387 38 1,628 

Edge of Field Buffering and Filtering 11,139 9 715 21,715 18 728 

Field Border 6,106 5 394 17,451 14 604 

Wind Erosion Control 4,222 4 283 9,244 7 340 

Northeast 

Overland Flow Control 2,057 29 241 2,100 28 206 

Concentrated Flow Control 1,172 16 159 1,453 19 144 

Edge of Field Buffering and Filtering 432 6 68 1,001 13 93 

Field Border 280*** 4*** 30 1,174 15 106 

Wind Erosion Control 281 4 40 812 11 77 

Northern Plains 

Overland Flow Control 3,982 8 98 3,406 7 76 

Concentrated Flow Control 3,296 7 102 5,513 11 117 

Edge of Field Buffering and Filtering 564*** 1*** 15 1,770 3 45 

Field Border 860 2 33 4,640 9 94 

Wind Erosion Control 5,110 11 147 6,788 13 163 

Northwest 

Overland Flow Control 1,665 12 139 4,146 31 149 

Concentrated Flow Control 834 6 55 1,523 11 54 

Edge of Field Buffering and Filtering 752 5 40 1,291 10 40 

Field Border 220*** 2*** 14 448*** 3*** 24 

Wind Erosion Control 194*** 1*** 12 400*** 3*** 21 

South Central 

Overland Flow Control 1,242 20 43 1,125 22 47 

Concentrated Flow Control 1,591 26 50 1,352 26 59 

Edge of Field Buffering and Filtering 308*** 5*** 13 769 15 31 

Field Border 274*** 4*** 10 856 17 40 

Wind Erosion Control 194*** 3*** 7 555*** 11*** 26 
 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 113 

Table A-5. Structural Practice Groups by Region, CEAP I and CEAP II—Cont. 

Region/Structural Practice Groups 

CEAP I CEAP II 

Acres (1,000s) 

Percent 

Regional 

Acres 

Count Acres 

(1,000s) 

Percent 

Regional 

Acres 

Count 

Southern and Central Plains 

Overland Flow Control 24,970 39 890 23,617 38 672 

Concentrated Flow Control 10,733 17 394 11,937 19 343 

Edge of Field Buffering and Filtering 1,448 2 55 3,133 5 102 

Field Border 641*** 1*** 30 2,393 4 80 

Wind Erosion Control 2,534 4 95 3,784 6 128 

Southwest 

Overland Flow Control 138*** 5*** 8 242*** 8*** 7 

Concentrated Flow Control 554*** 19*** 21 404*** 13*** 14 

Edge of Field Buffering and Filtering 0*** 0*** 0 0*** 0*** 0 

Field Border 62*** 2*** 3 243*** 8*** 7 

Wind Erosion Control 101*** 4*** 3 51*** 2*** 4 

National Summary 

Overland Flow Control 65,809 21 3,680 71,877 23 2,671 

Concentrated Flow Control 59,445 19 3,763 75,316 24 2,828 

Edge of Field Buffering and Filtering 17,422 6 1,146 33,403 11 1,312 

Field Border 11,233 4 729 34,022 11 1,416 

Wind Erosion Control 13,300 4 636 23,315 7 882 

*** Too few acres for significance change analysis 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

114 Conservation Effects Assessment Project 

Table A-6. Tillage Groups by Region, CEAP I and CEAP II 

Tillage Group and Region 

CEAP I CEAP II 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Count Acres 

(1,000s) 

Percent 

Regional 

Acres 

Count 

Conservation Tillage 

Atlantic and Gulf Coastal Plains 7,346 51 714 8,103 59 515 

California Coastal 854*** 19*** 7 584*** 15*** 14 

East Central 6,669 72 665 8,794 86 638 

Lower Mississippi and Texas Gulf Coast 9,679 44 949 8,891 43 651 

North Central and Midwest 74,160 62 5,166 90,644 74 3,185 

Northeast 2,809 39 412 4,859 64 470 

Northern Plains 30,583 63 995 38,341 75 961 

Northwest 4,013 29 264 7,104 53 282 

South Central 1,562 25 75 2,388 47 137 

Southern and Central Plains 19,066 30 822 40,203 64 1,119 

Southwest 383*** 13*** 24 622*** 20*** 30 

National 157,124 50 10,093 210,532 67 8,002 

Reduced Tillage 

Atlantic and Gulf Coastal Plains 3,633 25 315 3,533 26 209 

California Coastal 560*** 13*** 6 511*** 13*** 12 

East Central 2,149 23 207 2,108 21 146 

Lower Mississippi and Texas Gulf Coast 5,833 27 496 5,518 26 373 

North Central and Midwest 51,274 43 3,402 56,601 46 1,982 

Northeast 1,453 20 194 2,108 28 188 

Northern Plains 14,397 30 459 13,957 27 323 

Northwest 2,856 20 174 3,801 28 151 

South Central 1,093 18 54 1,659 32 100 

Southern and Central Plains 12,004 19 535 17,279 28 488 

Southwest 321*** 11*** 20 348*** 11*** 21 

National 95,572 31 5,862 107,423 34 3,993 

Continuous No Till 

Atlantic and Gulf Coastal Plains 3,713 26 399 4,570 33 306 

California Coastal 294*** 7*** 1 73*** 2*** 2 

East Central 4,520 49 458 6,685 66 492 

Lower Mississippi and Texas Gulf Coast 3,846 18 453 3,373 16 278 

North Central and Midwest 22,886 19 1,764 34,043 28 1,203 

Northeast 1,357 19 218 2,750 36 282 

Northern Plains 16,186 33 536 24,384 48 638 

Northwest 1,157 8 90 3,303 25 131 

South Central 469*** 8*** 21 729 14 37 

Southern and Central Plains 7,062 11 287 22,923 37 631 

Southwest 63*** 2*** 4 274*** 9*** 9 

National 61,553 20 4,231 103,108 33 4,009 

Conventional Tillage 

Atlantic and Gulf Coastal Plains 7,049 49 576 5,721 41 249 

California Coastal 3,593 81 104 3,329 85 193 

East Central 2,643 28 249 1,373 14 102 

Lower Mississippi and Texas Gulf Coast 12,137 56 871 12,025 57 739 

North Central and Midwest 45,973 38 2,899 32,652 26 1,020 

Northeast 4,381 61 476 2,738 36 196 

Northern Plains 17,838 37 523 12,789 25 251 

Northwest 9,997 71 784 6,334 47 265 

South Central 4,572 75 157 2,720 53 142 

Southern and Central Plains 45,271 70 1,793 22,529 36 684 

Southwest 2,487 87 166 2,561 80 105 

National 155,941 50 8,598 104,771 33 3,946 

*** Too few acres for significance change analysis 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 115 

Table A-7. Highly Erodible Land (HEL) Cultivated Cropland by Treatment Group and Region, CEAP I and 

CEAP II 

Treatment Group and Region 

CEAP I CEAP II 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Count Acres 

(1,000s) 

Percent 

Regional 

Acres 

Count 

Structural Practices plus Conservation Tillage 

Atlantic and Gulf Coastal Plains 153*** 18*** 15 213*** 25*** 18 

California Coastal 0*** 0*** 0 0*** 0*** 0 

East Central 1,294 40 135 2,036 55 144 

Lower Mississippi and Texas Gulf Coast 642 39 116 950 50 75 

North Central and Midwest 13,186 56 1,009 18,741 70 668 

Northeast 667 28 97 1,340 49 139 

Northern Plains 3,335 22 88 5,148 33 112 

Northwest 614 12 44 1,408 29 58 

South Central 38*** 11*** 3 196*** 35*** 8 

Southern and Central Plains 1,946 8 85 5,763 22 147 

Southwest 97*** 7*** 4 68*** 4*** 1 

National 21,971 28 1,596 35,862 42 1,370 

Structural Practices Only 

Atlantic and Gulf Coastal Plains 285*** 34*** 18 242*** 29*** 12 

California Coastal 8*** 31*** 1 58*** 28*** 2 

East Central 572 18 53 328*** 9*** 28 

Lower Mississippi and Texas Gulf Coast 156*** 9*** 22 46*** 2*** 4 

North Central and Midwest 3,368 14 244 2,912 11 110 

Northeast 689 29 88 305*** 11*** 29 

Northern Plains 1,648 11 47 680*** 4*** 17 

Northwest 824 16 57 894*** 18*** 27 

South Central 202*** 59*** 8 98*** 17*** 5 

Southern and Central Plains 6,120 25 251 3,270 12 104 

Southwest 255*** 18*** 16 364*** 20*** 11 

National 14,127 18 805 9,197 11 349 

Conservation Tillage Only 

Atlantic and Gulf Coastal Plains 205*** 25*** 21 275*** 33*** 26 

California Coastal 0*** 0*** 0 0*** 0*** 0 

East Central 1,136 35 120 1,209 33 98 

Lower Mississippi and Texas Gulf Coast 575 35 98 703 37 64 

North Central and Midwest 4,853 21 416 3,922 15 147 

Northeast 448 19 64 770 28 60 

Northern Plains 7,581 50 252 9,025 57 225 

Northwest 1,152 22 73 1,109 23 37 

South Central 20*** 6*** 2 118*** 21*** 9 

Southern and Central Plains 5,103 21 225 10,427 39 240 

Southwest 91*** 6*** 7 367*** 21*** 19 

National 21,164 27 1,278 27,926 33 925 

No Structural Practices or Conservation Tillage 

Atlantic and Gulf Coastal Plains 193*** 23*** 19 115*** 14*** 6 

California Coastal 19*** 69*** 1 153*** 72*** 7 

East Central 239*** 7*** 29 125*** 3*** 12 

Lower Mississippi and Texas Gulf Coast 291*** 18*** 27 213*** 11*** 15 

North Central and Midwest 2,055 9 158 1,072 4 38 

Northeast 601 25 71 300*** 11*** 20 

Northern Plains 2,537 17 84 911*** 6*** 26 

Northwest 2,694 51 193 1,461 30 49 

South Central 84*** 24*** 6 155*** 27*** 6 

Southern and Central Plains 11,472 47 536 7,309 27 198 

Southwest 969 69 71 985 55 39 

National 21,155 27 1,195 12,800 15 416 
 

 

 

 

 

 

 

116 Conservation Effects Assessment Project 

Table A-7. Highly Erodible Land (HEL) Cultivated Cropland by Treatment Group and Region, CEAP I and 

CEAP II—Cont. 

Treatment Group and Region 

CEAP I CEAP II 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Count Acres 

(1,000s) 

Percent 

Regional 

Acres 

Count 

National Summary 

Atlantic and Gulf Coastal Plains 835 6 73 844 6 62 

California Coastal 27*** 1*** 2 212*** 5*** 9 

East Central 3,241 35 337 3,699 36 282 

Lower Mississippi and Texas Gulf Coast 1,665 8 263 1,911 9 158 

North Central and Midwest 23,462 20 1,827 26,648 22 963 

Northeast 2,406 33 320 2,714 36 248 

Northern Plains 15,101 31 471 15,764 31 380 

Northwest 5,284 38 367 4,873 36 171 

South Central 344*** 6*** 19 568*** 11*** 28 

Southern and Central Plains 24,640 38 1,097 26,769 43 689 

Southwest 1,412 49 98 1,784 56 70 

National 78,417 25 4,874 85,785 27 3,060 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 117 

Table A-8. Cultivated Cropland with High and Moderately High Runoff (SVI) ratings by Treatment Group 

and Region, CEAP I and CEAP II 

Region and Treatment Group 

CEAP I CEAP II 

Acres 

(1,000s) Percent Acres (1,000s) Percent 

Atlantic and Gulf Coastal Plains 

Structural Practices, Conservation Tillage, or Both 

High 143 79 116 66 

Moderately High 920 82 1,171 80 

Structural Practices plus Conservation Tillage 

High 22 12 60 34 

Moderately High 209 19 368 25 

Conservation Tillage Only 

High 54 30 42 24 

Moderately High 431 38 563 39 

Structural Practices Only 

High 67 37 14 8 

Moderately High 279 25 239 16 

No Structural Practices or Conservation Tillage 

High 37 21 60 34 

Moderately High 204 18 290 20 

Regional Total 

High 180 1 176 1 

Moderately High 1,124 8 1,461 11 

California Coastal 

Structural Practices, Conservation Tillage, or Both 

High 0 0 101 100 

Moderately High 0 0 138 79 

Structural Practices plus Conservation Tillage 

High 0 0 44 43 

Moderately High 0 0 33 19 

Conservation Tillage Only 

High 0 0 0 0 

Moderately High 0 0 0 0 

Structural Practices Only 

High 0 0 57 57 

Moderately High 0 0 105 60 

No Structural Practices or Conservation Tillage 

High 0 0 0 0 

Moderately High 50 100 36 21 

Regional Total 

High 0 0 101 3 

Moderately High 50 1 174 4 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

118 Conservation Effects Assessment Project 

Table A-8. Cultivated Cropland with High and Moderately High Runoff (SVI) ratings by Treatment Group 

and Region, CEAP I and CEAP II—Cont. 

Region and Treatment Group 

CEAP I CEAP II 

Acres 

(1,000s) Percent Acres (1,000s) Percent 

East Central 

Structural Practices, Conservation Tillage, or Both 

High 1,519 93 2,153 96 

Moderately High 2,364 86 2,832 95 

Structural Practices plus Conservation Tillage 

High 501 31 1,126 50 

Moderately High 1,122 41 1,401 47 

Conservation Tillage Only 

High 606 37 801 36 

Moderately High 914 33 1,330 45 

Structural Practices Only 

High 412 25 226 10 

Moderately High 328 12 100 3 

No Structural Practices or Conservation Tillage 

High 110 7 98 4 

Moderately High 373 14 150 5 

Regional Total 

High 1,629 17 2,250 22 

Moderately High 2,737 29 2,982 29 

Lower Mississippi and Texas Gulf Coast 

Structural Practices, Conservation Tillage, or Both 

High 398 95 564 95 

Moderately High 1,606 78 1,827 86 

Structural Practices plus Conservation Tillage 

High 162 39 299 51 

Moderately High 654 32 925 44 

Conservation Tillage Only 

High 223 53 264 45 

Moderately High 721 35 834 39 

Structural Practices Only 

High 13 3 0 0 

Moderately High 232 11 68 3 

No Structural Practices or Conservation Tillage 

High 21 5 27 5 

Moderately High 447 22 290 14 

Regional Total 

High 419 2 590 3 

Moderately High 2,053 9 2,117 10 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 119 

Table A-8. Cultivated Cropland with High and Moderately High Runoff (SVI) ratings by Treatment Group 

and Region, CEAP I and CEAP II—Cont. 

Region and Treatment Group 

CEAP I CEAP II 

Acres 

(1,000s) Percent Acres (1,000s) Percent 

North Central and Midwest 

Structural Practices, Conservation Tillage, or Both 

High 13,908 92 18,737 97 

Moderately High 19,567 83 22,162 90 

Structural Practices plus Conservation Tillage 

High 9,000 59 14,673 76 

Moderately High 9,232 39 13,941 57 

Conservation Tillage Only 

High 2,501 16 2,312 12 

Moderately High 6,420 27 5,130 21 

Structural Practices Only 

High 2,406 16 1,752 9 

Moderately High 3,916 17 3,092 13 

No Structural Practices or Conservation Tillage 

High 1,270 8 640 3 

Moderately High 4,018 17 2,505 10 

Regional Total 

High 15,178 13 19,377 16 

Moderately High 23,585 20 24,668 20 

Northeast 

Structural Practices, Conservation Tillage, or Both 

High 1,403 76 1,926 79 

Moderately High 1,230 64 1,691 80 

Structural Practices plus Conservation Tillage 

High 532 29 1,142 47 

Moderately High 314 16 616 29 

Conservation Tillage Only 

High 315 17 500 21 

Moderately High 465 24 678 32 

Structural Practices Only 

High 556 30 284 12 

Moderately High 451 24 397 19 

No Structural Practices or Conservation Tillage 

High 432 24 500 21 

Moderately High 683 36 425 20 

Regional Total 

High 1,834 26 2,426 32 

Moderately High 1,913 27 2,116 28 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

120 Conservation Effects Assessment Project 

Table A-8. Cultivated Cropland with High and Moderately High Runoff (SVI) ratings by Treatment Group 

and Region, CEAP I and CEAP II—Cont. 

Region and Treatment Group 

CEAP I CEAP II 

Acres 

(1,000s) Percent Acres (1,000s) Percent 

Northern Plains 

Structural Practices, Conservation Tillage, or Both 

High 2,710 87 2,837 95 

Moderately High 8,846 79 9,541 97 

Structural Practices plus Conservation Tillage 

High 384 12 1,118 37 

Moderately High 2,022 18 3,415 35 

Conservation Tillage Only 

High 1,934 62 1,714 57 

Moderately High 5,559 50 5,434 55 

Structural Practices Only 

High 392 13 5 0.2 

Moderately High 1,264 11 692 7 

No Structural Practices or Conservation Tillage 

High 417 13 152 5 

Moderately High 2,310 21 316 3 

Regional Total 

High 3,128 6 2,990 6 

Moderately High 11,155 23 9,857 19 

Northwest 

Structural Practices, Conservation Tillage, or Both 

High 2,123 64 3,321 86 

Moderately High 1,395 44 2,386 69 

Structural Practices plus Conservation Tillage 

High 641 19 1,575 41 

Moderately High 216 7 1,021 30 

Conservation Tillage Only 

High 775 24 742 19 

Moderately High 752 24 873 25 

Structural Practices Only 

High 707 21 1,005 26 

Moderately High 427 13 493 14 

No Structural Practices or Conservation Tillage 

High 1,173 36 536 14 

Moderately High 1,788 56 1,049 31 

Regional Total 

High 3,296 24 3,858 29 

Moderately High 3,183 23 3,436 26 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 121 

Table A-8. Cultivated Cropland with High and Moderately High Runoff (SVI) ratings by Treatment Group 

and Region, CEAP I and CEAP II—Cont. 

Region and Treatment Group 

CEAP I CEAP II 

Acres 

(1,000s) Percent Acres (1,000s) Percent 

South Central 

Structural Practices, Conservation Tillage, or Both 

High 20 100 133 63 

Moderately High 1,158 70 1,293 78 

Structural Practices plus Conservation Tillage 

High 0 0 71 34 

Moderately High 348 21 431 26 

Conservation Tillage Only 

High 20 100 62 29 

Moderately High 183 11 283 17 

Structural Practices Only 

High 0 0 0 0 

Moderately High 627 38 579 35 

No Structural Practices or Conservation Tillage 

High 0 0 78 37 

Moderately High 499 30 374 22 

Regional Total 

High 20 0.3 211 4 

Moderately High 1,657 27 1,667 33 

Southern and Central Plains 

Structural Practices, Conservation Tillage, or Both 

High 1,195 86 1,453 94 

Moderately High 5,092 85 8,862 95 

Structural Practices plus Conservation Tillage 

High 362 26 866 56 

Moderately High 1,322 22 4,679 50 

Conservation Tillage Only 

High 258 19 441 29 

Moderately High 809 13 2,253 24 

Structural Practices Only 

High 574 41 146 9 

Moderately High 2,962 49 1,929 21 

No Structural Practices or Conservation Tillage 

High 198 14 87 6 

Moderately High 926 15 478 5 

Regional Total 

High 1,393 2 1,539 2 

Moderately High 6,018 9 9,340 15 
 

 

 

 

 

 

 

 

 

 

122 Conservation Effects Assessment Project 

Table A-8. Cultivated Cropland with High and Moderately High Runoff (SVI) ratings by Treatment Group 

and Region, CEAP I and CEAP II—Cont. 

Region and Treatment Group 

CEAP I CEAP II 

Acres 

(1,000s) Percent Acres (1,000s) Percent 

Southwest 

Structural Practices, Conservation Tillage, or Both 

High 35 51 0 0 

Moderately High 72 29 212 61 

Structural Practices plus Conservation Tillage 

High 0 0 0 0 

Moderately High 58 24 68 19 

Conservation Tillage Only 

High 20 30 0 0 

Moderately High 14 6 59 17 

Structural Practices Only 

High 15 22 0 0 

Moderately High 0 0 85 24 

No Structural Practices or Conservation Tillage 

High 33 49 14 100 

Moderately High 174 71 136 39 

Regional Total 

High 68 2 14 0.4 

Moderately High 247 9 349 11 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 123 

Table A-9. Conservation Crop Rotations by Group and Region, CEAP II 

Region and Crop 

Rotation Group 

Acres 

(1,000) Count 

Acres with 

Conservation 

Crop Rotations* 

Acres with HighBiomass 

Conservation 

Crop Rotations** 

Acres without Conservation Crop 

Rotations 

Total 

Acres with Idle in 

one or more years 

of the Rotation 

Percent 

Atlantic and Gulf Coastal Plains 

Hay with other 

crops 

451 25 89.4 87.7 10.6 14.1 

Close-grown 

crops, no hay or 

row crops 

805 8 98.5 98.5 1.5 0.0 

Row and closegrown crops, no 

hay 

2,325 183 94.5 82.2 5.5 0.0 

Row crops, no 

close-grown or 

hay 

10,244 548 34.8 19.4 65.2 4.2 

All cultivated 

cropland 

California Coastal 

Hay with other 

crops 

13,825 

447 

764 

23 

50.3 

92.6 

36.8 

83.1 

49.7 

7.4 

4.2 

0.0 

Close-grown 

crops, no hay or 

row crops 

1,641 65 75.7 75.7 24.3 100.0 

Row and closegrown crops, no 

hay 

816 38 64.0 64.0 36.0 27.8 

Row crops, no 

close-grown or 

hay 

1,009 81 27.4 26.5 72.6 7.9 

All cultivated 

cropland 

East Central 

Hay with other 

crops 

3,913 

833 

207 

54 

62.7 

99.0 

61.4 

89.4 

37.3 

1.0 

36.9 

100.0 

Close-grown 

crops, no hay or 

row crops 

100 6 100.0 100.0 0.0 0.0 

Row and closegrown crops, no 

hay 

2,002 155 96.1 82.3 3.9 66.6 

Row crops, no 

close-grown or 

hay 

7,231 525 68.0 22.3 32.0 3.7 

All cultivated 

cropland 10,166 740 76.4 40.4 23.6 6.0 

Lower Mississippi and Texas Gulf Coast 

Hay with other 

crops 

277 15 72.1 66.5 27.9 67.5 

Close-grown 

crops, no hay or 

row crops 

3,195 171 58.9 56.3 41.1 99.2 

Row and closegrown crops, no 

hay 

4,190 290 81.7 27.8 18.3 22.0 

Row crops, no 

close-grown or 

hay 

13,254 914 36.6 8.1 63.4 6.1 

All cultivated 

cropland 20,916 1,390 49.5 20.2 50.5 19.3 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

124 Conservation Effects Assessment Project 

Table A-9. Conservation Crop Rotations by Group and Region, CEAP II—Cont. 

Region and Crop 

Rotation Group 

Acres 

(1,000) Count 

Acres with 

Conservation 

Crop Rotations* 

Acres with HighBiomass 

Conservation 

Crop Rotations** 

Acres without Conservation Crop 

Rotations 

Total 

Acres with Idle in 

one or more years 

of the Rotation 

Percent 

North Central and Midwest 

Hay with other 

crops 6,539 154 96.6 94.8 3.4 0.0 

Close-grown 

crops, no hay or 

row crops 

785 7 22.4 22.4 77.6 100.0 

Row and closegrown crops, no 

hay 

10,601 382 79.9 31.0 20.1 8.5 

Row crops, no 

close-grown or 

hay 

105,371 3,662 88.1 14.2 11.9 11.3 

All cultivated 

cropland 

Northeast 

Hay with other 

crops 

123,296 

1,669 

4,205 

124 

87.4 

96.3 

20.0 

95.3 

12.6 

3.7 

14.2 

100.0 

Close-grown 

crops, no hay or 

row crops 

118 8 79.3 79.3 20.7 100.0 

Row and closegrown crops, no 

hay 

1,751 161 84.3 63.7 15.7 58.4 

Row crops, no 

close-grown or 

hay 

4,059 373 73.4 31.6 26.6 6.2 

All cultivated 

cropland 

Northern Plains 

Hay with other 

crops 

7,597 

2,635 

666 

84 

81.0 

86.3 

53.7 

74.2 

19.0 

13.7 

21.7 

91.8 

Close-grown 

crops, no hay or 

row crops 

13,636 296 46.7 30.9 53.3 94.8 

Row and closegrown crops, no 

hay 

21,156 483 63.2 11.1 36.8 12.3 

Row crops, no 

close-grown or 

hay 

13,703 349 64.1 9.3 35.9 7.6 

All cultivated 

cropland 51,130 1,212 60.2 19.2 39.8 42.1 

Northwest 

Hay with other 

crops 1,437 83 99.1 96.1 0.9 100.0 

Close-grown 

crops, no hay or 

row crops 

7,694 280 28.0 26.1 72.0 98.1 

Row and closegrown crops, no 

hay 

3,376 136 51.0 13.3 49.0 11.2 

Row crops, no 

close-grown or 

hay 

931 48 12.7 6.2 87.3 3.0 

All cultivated 

cropland 13,438 547 40.3 29.0 59.7 70.6 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 125 

Table A-9. Conservation Crop Rotations by Group and Region, CEAP II—Cont. 

Region and Crop 

Rotation Group 

South Central 

Hay with other 

crops 

Acres 

(1,000) 

453 

Count 

32 

Acres with 

Conservation 

Crop Rotations* 

Acres with HighBiomass 

Conservation 

Crop Rotations** 

Acres without Conservation Crop 

Rotations 

Total 

Acres with Idle in 

one or more years 

of the Rotation 

Percent 

100.0 95.7 0.0 0.0 

Close-grown 

crops, no hay or 

row crops 

530 31 51.0 46.4 49.0 100.0 

Row and closegrown crops, no 

hay 

2,011 111 92.8 66.3 7.2 34.2 

Row crops, no 

close-grown or 

hay 

2,113 105 55.5 26.1 44.5 22.5 

All cultivated 

cropland 

Southern and Cent

Hay with other 

crops 

5,107 

ral Plains 

4,852 

279 

141 

73.7 

71.3 

50.2 

65.5 

26.3 

28.7 

38.7 

80.5 

Close-grown 

crops, no hay or 

row crops 

18,157 464 53.9 51.9 46.1 99.0 

Row and closegrown crops, no 

hay 

16,919 427 55.6 34.1 44.4 88.4 

Row crops, no 

close-grown or 

hay 

22,804 771 58.4 26.2 41.6 10.2 

All cultivated 

cropland 

Southwest 

Hay with other 

crops 

62,732 

1,193 

1,803 

42 

57.4 

90.1 

38.8 

90.1 

42.6 

9.9 

63.6 

7.4 

Close-grown 

crops, no hay or 

row crops 

630 23 30.1 30.1 69.9 100.0 

Row and closegrown crops, no 

hay 

571 25 48.2 16.0 51.8 21.4 

Row crops, no 

close-grown or 

hay 

790 45 11.4 11.4 88.6 26.4 

All cultivated 

cropland 3,183 135 51.2 45.4 48.8 44.9 

* Acres with a crop rotation biomass index score greater than or equal to 1.5 

** Acres with a crop rotation biomass index score greater than or equal to 2.0 
 

 

 

 

 

 

126 Conservation Effects Assessment Project 

Table A-10. Nitrogen Application by Incorporation and Region, CEAP I and CEAP II 

Region Applications 

Incorporated 

CEAP I CEAP II 

Applied Acres 

(1,000s) 

Average 

Annual 

Load (Tons) 

Count Applied Acres 

(1,000s) 

Average 

Annual 

Load (Tons) 

Count 

Atlantic and Gulf Coastal Plains 

All 5,244 223,611 430 2,716 93,937 143 

Some 5,191 258,082 500 5,775 282,570 317 

None 3,187 119,621 288 4,403 160,678 246 

California Coastal 

All 2,130 152,210 64 904 42,705 45 

Some 895 108,644 34 2,134 191,172 118 

None 631 69,242 9 494 23,508 37 

East Central 

All 2,376 115,143 234 1,192 48,978 79 

Some 3,651 182,313 366 3,528 184,091 258 

None 2,872 131,247 277 4,947 234,656 366 

Lower Mississippi and Texas Gulf Coast 

All 6,700 316,551 487 4,324 196,616 229 

Some 6,345 337,315 538 6,540 391,308 441 

None 4,706 210,066 469 5,592 260,718 404 

North Central and Midwest 

All 55,860 2,183,989 3694 40,029 1,727,760 1361 

Some 45,794 2,074,316 3061 58,035 2,810,193 1966 

None 13,694 449,583 969 20,292 740,370 734 

Northeast 

All 2,414 97,128 262 1,774 66,953 142 

Some 3,454 199,569 416 3,613 200,187 307 

None 1,065 50,468 178 1,994 98,583 192 

Northern Plains 

All 33,146 801,565 1004 26,274 811,072 592 

Some 10,501 317,500 349 17,514 687,296 423 

None 2,822 82,520 101 4,768 175,509 138 

Northwest 

All 8,031 252,198 566 6,553 191,570 244 

Some 3,761 227,441 294 3,943 240,744 164 

None 1,901 97,545 166 2,499 118,957 116 

South Central 

All 2,575 113,403 81 1,441 53,710 66 

Some 1,839 88,189 80 1,765 93,604 107 

None 1,535 61,199 62 1,431 70,784 77 

Southern and Central Plains 

All 32,737 978,233 1332 21,331 599,833 615 

Some 18,498 710,712 764 24,923 989,328 712 

None 8,083 230,505 319 10,419 299,894 306 

Southwest 

All 1,052 41,340 85 884 30,694 35 

Some 1,418 140,917 78 1,246 106,003 54 

None 277 10,944 23 788 39,501 32 
 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 127 

Table A-11. Phosphorus Application by Incorporation and Region, CEAP I and CEAP II 

Region Applications 

Incorporated 

CEAP I CEAP II 

Applied Acres 

(1,000s) 

Average 

Annual Load 

(Tons) 

Count Applied Acres 

(1,000s) 

Average 

Annual Load 

(tons) 

Count 

Atlantic and Gulf Coastal Plains 

All 4,803 57,643 398 2,657 29,365 130 

Some 5,056 62,825 485 5,463 61,980 296 

None 3,083 31,719 279 4,158 40,467 236 

California Coastal 

All 1,370 25,536 48 575 6,709 30 

Some 895 19,997 34 2,052 38,484 112 

None 505 6,835 6 376 5,835 31 

East Central 

All 2,373 33,011 234 1,193 14,724 77 

Some 3,569 49,516 361 3,350 46,103 248 

None 2,750 37,397 270 5,003 73,192 372 

Lower Mississippi and Texas Gulf Coast 

All 6,113 54,586 453 5,991 60,286 346 

Some 6,144 64,164 519 6,276 76,950 423 

None 4,128 39,482 435 5,467 53,851 398 

North Central and Midwest 

All 55,107 523,582 3650 40,118 439,128 1371 

Some 45,455 527,005 3036 57,329 700,839 1941 

None 13,320 135,044 934 19,502 243,774 717 

Northeast 

All 2,357 28,217 259 1,662 16,679 132 

Some 3,402 57,679 408 3,541 52,187 301 

None 982 15,378 165 1,877 25,973 181 

Northern Plains 

All 30,423 168,544 924 25,339 189,356 580 

Some 10,386 66,158 346 17,314 141,363 417 

None 2,416 16,479 85 4,308 40,965 128 

Northwest 

All 5,180 46,167 372 5,718 39,055 202 

Some 3,452 43,997 270 3,533 54,901 149 

None 1,290 16,859 116 1,897 23,879 97 

South Central 

All 1,935 16,396 64 1,386 12,452 70 

Some 1,839 17,909 80 1,732 19,602 105 

None 1,104 8,958 52 1,148 11,787 63 

Southern and Central Plains 

All 23,010 151,936 950 15,894 111,530 457 

Some 17,817 123,911 731 23,844 194,861 679 

None 5,929 39,874 237 7,911 58,405 231 

Southwest 

All 705 10,492 54 462 4,145 18 

Some 1,378 36,443 74 1,160 30,445 52 

None 197 3,835 16 624 10,925 24 
 

 

 

 

 

 

 

 

128 Conservation Effects Assessment Project 

Table A-12. Nitrogen Application Timing and Incorporation by Region, CEAP I and CEAP II 

Region Timing Incorporation 

CEAP I CEAP II 

Application 

Acres (1,000s) 

Average 

Annual 

Load 

(Tons) 

Count Application 

Acres (1,000s) 

Average 

Annual 

Load 

(Tons) 

Count 

Atlantic and Gulf Coastal Plains 

Pre-plant 7-21 days 

Incorporated 2,009 53,748 148 1,338 25,076 72 

Not Incorporated 1,330 19,594 147 2,128 23,280 137 

Pre-plant >21 days 

Incorporated 1,551 39,680 135 1,604 35,720 80 

Not Incorporated 1,864 41,921 175 2,786 52,473 184 

At-plant 

Incorporated 5,970 112,671 559 4,861 77,667 267 

Not Incorporated 3,260 56,835 351 4,282 89,899 275 

Post-plant 

Incorporated 5,388 159,607 453 3,707 103,919 216 

Not Incorporated 3,310 89,831 252 4,454 109,239 205 

California Coastal 

Pre-plant 7-21 days 

Incorporated 450 22,533 19 770 30,165 46 

Not Incorporated 107 1,881 4 377 6,190 26 

Pre-plant >21 days 

Incorporated 531 18,168 14 595 35,420 32 

Not Incorporated 259 4,872 8 829 14,451 42 

At-plant 

Incorporated 2,082 99,429 60 2,055 69,988 107 

Not Incorporated 488 23,817 12 883 17,879 55 

Post-plant 

Incorporated 915 38,846 30 345 12,554 24 

Not Incorporated 972 48,653 23 1,665 36,510 106 

East Central 

Pre-plant 7-21 days 

Incorporated 829 21,942 79 499 15,596 35 

Not Incorporated 1,387 30,321 139 2,198 55,113 174 

Pre-plant >21 days 

Incorporated 622 18,252 60 418 11,759 31 

Not Incorporated 1,521 37,875 150 3,087 76,811 247 

At-plant 

Incorporated 4,147 98,213 419 3,088 63,761 226 

Not Incorporated 3,421 90,711 329 4,260 111,588 306 

Post-plant 

Incorporated 2,243 62,354 229 1,743 47,439 120 

Not Incorporated 1,632 41,053 173 2,725 67,115 215 

Lower Mississippi and Texas Gulf Coast 

Pre-plant 7-21 days 

Incorporated 895 25,034 93 1,453 43,356 82 

Not Incorporated 1,153 28,968 134 1,279 31,085 83 

Pre-plant >21 days 

Incorporated 1,551 44,304 100 2,055 62,387 93 

Not Incorporated 1,174 35,077 126 2,069 51,938 144 

At-plant 

Incorporated 5,292 156,629 448 3,313 98,646 219 

Not Incorporated 3,157 76,663 347 4,238 103,045 318 

Post-plant 

Incorporated 5,335 226,024 408 3,403 116,399 210 

Not Incorporated 6,397 239,179 497 8,074 332,255 549 
 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 129 

Table A-12. Nitrogen Application Timing and Incorporation by Region, CEAP I and CEAP II—Cont. 

Region Timing Incorporation 

CEAP I CEAP II 

Application 

Acres (1,000s) 

Average 

Annual 

Load 

(Tons) 

Count Application 

Acres (1,000s) 

Average 

Annual 

Load 

(Tons) 

Count 

North Central and Midwest 

Pre-plant 7-21 days 

Incorporated 13,001 373,286 860 17,471 531,202 608 

Not Incorporated 5,927 116,001 424 13,854 229,789 460 

Pre-plant >21 days 

Incorporated 34,525 1,081,118 2086 31,782 956,353 1040 

Not Incorporated 23,696 445,569 1497 33,411 512,203 1152 

At-plant 

Incorporated 63,656 1,428,509 4445 53,376 1,096,451 1836 

Not Incorporated 19,078 370,455 1425 22,846 421,154 844 

Post-plant 

Incorporated 18,445 549,272 1365 34,288 1,019,138 1204 

Not Incorporated 8,959 198,436 618 23,731 396,842 813 

Northeast 

Pre-plant 7-21 days 

Incorporated 676 15,950 85 536 12,607 48 

Not Incorporated 715 13,938 97 1,117 20,123 119 

Pre-plant >21 days 

Incorporated 849 24,404 106 702 21,065 50 

Not Incorporated 1,670 51,822 214 2,219 56,373 209 

At-plant 

Incorporated 5,085 110,990 562 4,547 79,961 375 

Not Incorporated 1,832 41,073 275 2,979 64,978 271 

Post-plant 

Incorporated 1,068 24,104 131 1,422 28,657 116 

Not Incorporated 1,539 44,990 200 1,972 56,664 179 

Northern Plains 

Pre-plant 7-21 days 

Incorporated 3,279 48,749 96 3,586 75,321 82 

Not Incorporated 1,381 22,674 50 4,276 84,760 105 

Pre-plant >21 days 

Incorporated 7,524 166,828 215 6,173 168,488 123 

Not Incorporated 3,634 71,176 123 5,768 121,557 149 

At-plant 

Incorporated 39,155 674,359 1212 37,704 743,358 886 

Not Incorporated 5,711 100,792 206 10,448 228,100 274 

Post-plant 

Incorporated 889 20,406 38 2,993 43,103 76 

Not Incorporated 1,374 27,454 46 3,761 60,951 94 

Northwest 

Pre-plant 7-21 days 

Incorporated 2,272 55,078 177 1,580 44,412 73 

Not Incorporated 313 7,422 34 1,021 24,266 46 

Pre-plant >21 days 

Incorporated 3,538 81,157 253 3,462 75,972 107 

Not Incorporated 1,350 41,908 107 3,003 54,227 139 

At-plant 

Incorporated 7,177 179,737 540 7,018 153,595 282 

Not Incorporated 1,229 29,478 98 1,398 34,210 54 

Post-plant 

Incorporated 567 14,195 59 514 15,598 26 

Not Incorporated 827 40,050 84 902 48,380 55 
 

 

 

 

 

130 Conservation Effects Assessment Project 

Table A-12. Nitrogen Application Timing and Incorporation by Region, CEAP I and CEAP II—Cont. 

Region Timing Incorporation 

CEAP I CEAP II 

Application 

Acres 

(1,000s) 

Average 

Annual 

Load 

(Tons) 

Count 

Application 

Acres 

(1,000s) 

Average 

Annual 

Load 

(Tons) 

Count 

South Central 

Pre-plant 7-21 days 

Incorporated 725 11,253 23 591 8,817 32 

Not Incorporated 149 2,014 12 407 9,044 22 

Pre-plant >21 days 

Incorporated 1,192 28,993 35 1,358 28,950 63 

Not Incorporated 628 17,607 23 1,597 37,138 86 

At-plant 

Incorporated 2,899 72,426 109 1,373 31,699 76 

Not Incorporated 1,368 31,729 56 933 17,274 57 

Post-plant 

Incorporated 1,143 28,580 38 831 23,563 38 

Not Incorporated 845 25,200 45 1,279 48,376 69 

Southern and Central Plains 

Pre-plant 7-21 days 

Incorporated 5,410 113,824 236 5,841 111,789 183 

Not Incorporated 2,581 44,788 114 5,340 79,432 148 

Pre-plant >21 days 

Incorporated 17,331 462,332 707 16,325 398,124 453 

Not Incorporated 8,930 175,751 363 20,335 336,036 590 

At-plant 

Incorporated 33,379 589,547 1359 26,598 340,601 795 

Not Incorporated 8,167 146,985 327 9,471 153,151 298 

Post-plant 

Incorporated 4,627 144,481 217 7,221 164,236 210 

Not Incorporated 3,742 103,375 185 8,650 211,432 259 

Southwest 

Pre-plant 7-21 days 

Incorporated 466 8,031 24 285 5,305 15 

Not Incorporated 120 4,490 8 85 1,743 8 

Pre-plant >21 days 

Incorporated 572 21,774 47 593 20,936 30 

Not Incorporated 394 13,578 26 983 16,364 35 

At-plant 

Incorporated 1,289 36,070 78 1,318 30,655 50 

Not Incorporated 474 6,346 18 466 9,308 18 

Post-plant 

Incorporated 633 27,243 51 506 20,236 17 

Not Incorporated 518 21,618 35 942 46,788 39 
 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 131 

Table A-13. Phosphorus Application Timing and Incorporation by Region, CEAP I and CEAP II 

Region Timing Incorporation 

CEAP I CEAP II 

Application 

Acres (1,000s) 

Average 

Annual 

Load 

(Tons) 

Count Application 

Acres (1,000s) 

Average 

Annual 

Load 

(Tons) 

Count 

Atlantic and Gulf Coastal Plains 

Pre-plant 7-21 days 

Incorporated 1,996 17,504 149 1,309 9,661 72 

Not Incorporated 1,311 8,700 150 2,357 14,396 134 

Pre-plant >21 days 

Incorporated 1,713 18,165 163 1,874 13,911 78 

Not Incorporated 2,017 17,362 175 2,251 17,980 134 

At-plant 

Incorporated 5,057 38,618 476 3,469 21,904 208 

Not Incorporated 2,937 23,092 303 3,598 25,278 226 

Post-plant 

Incorporated 1,389 16,842 84 1,232 13,673 37 

Not Incorporated 1,143 8,482 93 2,222 12,733 83 

California Coastal 

Pre-plant 7-21 days 

Incorporated 187 5,890 8 413 3,391 27 

Not Incorporated 107 950 4 243 1,325 17 

Pre-plant >21 days 

Incorporated 474 4,543 11 552 11,572 25 

Not Incorporated 191 1,473 6 641 4,859 28 

At-plant 

Incorporated 1,425 17,279 43 1,172 10,984 71 

Not Incorporated 707 5,784 12 589 5,423 38 

Post-plant 

Incorporated 160 2,504 8 187 1,802 13 

Not Incorporated 460 4,980 12 712 5,477 41 

East Central 

Pre-plant 7-21 days 

Incorporated 754 6,882 71 334 3,120 25 

Not Incorporated 1,364 12,172 140 2,331 22,991 180 

Pre-plant >21 days 

Incorporated 733 7,757 69 376 3,441 28 

Not Incorporated 1,556 15,689 164 2,878 30,139 224 

At-plant 

Incorporated 3,574 36,282 355 2,400 19,282 174 

Not Incorporated 3,169 30,397 317 3,950 39,247 287 

Post-plant 

Incorporated 426 5,165 38 278 1,644 18 

Not Incorporated 514 3,780 58 1,269 8,272 102 

Lower Mississippi and Texas Gulf Coast 

Pre-plant 7-21 days 

Incorporated 1,063 7,289 87 2,323 21,581 130 

Not Incorporated 1,174 9,121 143 1,520 10,665 95 

Pre-plant >21 days 

Incorporated 2,278 17,184 142 3,202 27,239 175 

Not Incorporated 1,489 11,027 148 2,029 14,220 131 

At-plant 

Incorporated 6,071 49,507 487 6,077 54,992 395 

Not Incorporated 3,019 24,657 360 4,210 35,131 327 

Post-plant 

Incorporated 1,504 15,377 99 1,118 7,835 65 

Not Incorporated 2,541 22,607 207 2,432 18,645 163 
 

 

 

 

 

 

 

132 Conservation Effects Assessment Project 

Table A-13. Phosphorus Application Timing and Incorporation by Region, CEAP I and CEAP II—Cont. 

Region Timing Incorporation 

CEAP I CEAP II 

Application 

Acres (1,000s) 

Average 

Annual 

Load 

(Tons) 

Count Application 

Acres (1,000s) 

Average 

Annual 

Load 

(Tons) 

Count 

North Central and Midwest 

Pre-plant 7-21 days 

Incorporated 8,436 64,514 525 10,564 86,430 358 

Not Incorporated 5,241 41,200 381 12,109 97,621 421 

Pre-plant >21 days 

Incorporated 24,702 226,077 1475 21,034 183,942 668 

Not Incorporated 28,758 287,610 1827 34,713 317,150 1173 

At-plant 

Incorporated 55,364 391,995 3968 45,684 342,303 1626 

Not Incorporated 14,863 109,934 1119 14,728 105,457 560 

Post-plant 

Incorporated 2,752 26,268 170 9,570 85,852 299 

Not Incorporated 2,489 19,463 181 17,352 132,296 602 

Northeast 

Pre-plant 7-21 days 

Incorporated 725 5,806 94 499 3,152 44 

Not Incorporated 611 4,058 82 962 7,689 102 

Pre-plant >21 days 

Incorporated 905 10,320 113 696 6,878 52 

Not Incorporated 1,652 19,282 211 1,738 17,428 160 

At-plant 

Incorporated 4,524 37,597 499 3,762 23,978 301 

Not Incorporated 1,275 8,344 189 2,127 15,914 189 

Post-plant 

Incorporated 323 2,198 48 248 1,312 19 

Not Incorporated 704 9,016 83 953 9,770 82 

Northern Plains 

Pre-plant 7-21 days 

Incorporated 1,720 8,797 58 2,955 18,282 71 

Not Incorporated 554 1,802 20 2,121 10,773 52 

Pre-plant >21 days 

Incorporated 4,272 23,892 133 4,684 29,479 99 

Not Incorporated 2,133 12,313 71 2,980 25,881 81 

At-plant 

Incorporated 36,486 185,236 1117 36,739 220,223 859 

Not Incorporated 2,546 10,935 102 6,506 35,440 174 

Post-plant 

Incorporated 174 1,395 9 1,908 8,889 45 

Not Incorporated 252 1,439 9 1,029 4,925 32 

Northwest 

Pre-plant 7-21 days 

Incorporated 1,634 12,257 133 1,224 7,879 60 

Not Incorporated 266 1,583 27 671 4,631 30 

Pre-plant >21 days 

Incorporated 1,465 15,801 129 1,674 17,121 67 

Not Incorporated 900 10,628 74 1,177 6,686 66 

At-plant 

Incorporated 5,556 37,138 418 6,596 38,827 243 

Not Incorporated 890 6,678 65 1,095 5,512 42 

Post-plant 

Incorporated 629 3,604 45 286 3,028 13 

Not Incorporated 417 3,639 50 626 16,044 37 
 

 

 

 

 

Conservation Practices on Cultivated Cropland 133 

Table A-13. Phosphorus Application Timing and Incorporation by Region, CEAP I and CEAP II—Cont. 

Region Timing Incorporation 

CEAP I CEAP II 

Application 

Acres 

(1,000s) 

Average 

Annual 

Load 

(Tons) 

Count 

Application 

Acres 

(1,000s) 

Average 

Annual 

Load 

(Tons) 

Count 

South Central 

Pre-plant 7-21 days 

Incorporated 740 4,810 28 664 3,855 37 

Not Incorporated 165 876 12 404 2,826 14 

Pre-plant >21 days 

Incorporated 976 5,444 31 1,174 7,143 58 

Not Incorporated 344 1,430 17 845 5,185 44 

At-plant 

Incorporated 2,062 16,331 87 1,566 12,344 89 

Not Incorporated 971 5,240 43 659 4,988 38 

Post-plant 

Incorporated 317 2,133 14 399 2,702 17 

Not Incorporated 437 2,165 23 463 2,962 24 

Southern and Central Plains 

Pre-plant 7-21 days 

Incorporated 3,048 14,684 140 3,880 21,798 117 

Not Incorporated 1,599 9,669 71 3,151 14,294 85 

Pre-plant >21 days 

Incorporated 10,201 68,140 417 7,802 49,419 218 

Not Incorporated 4,426 27,250 188 9,671 62,787 282 

At-plant 

Incorporated 26,294 140,971 1065 24,836 138,651 721 

Not Incorporated 5,034 25,147 189 6,457 31,514 186 

Post-plant 

Incorporated 1,449 10,553 63 2,041 11,642 69 

Not Incorporated 893 6,324 42 3,407 16,147 91 

Southwest 

Pre-plant 7-21 days 

Incorporated 264 2,981 20 242 2,610 10 

Not Incorporated 91 2,076 6 57 1,244 5 

Pre-plant >21 days 

Incorporated 500 9,417 38 443 11,001 22 

Not Incorporated 285 6,479 18 480 3,431 21 

At-plant 

Incorporated 850 11,163 55 883 6,688 34 

Not Incorporated 257 4,430 9 397 6,952 13 

Post-plant 

Incorporated 166 956 18 162 1,350 4 

Not Incorporated 76 3,191 6 208 1,233 12 
 

 

 

 

 

 

 

 

 

 

 

 

134 Conservation Effects Assessment Project 

Table A-14. Sheet and Rill Erosion Relative to Threshold by Region, CEAP I and CEAP II 

Region 

Cultivated Cropland 

Exceeding Threshold 

Cultivated Cropland 

Meeting Threshold 

Loss on Acres 

Exceeding Threshold 

Loss on Acres 

Meeting Threshold 

Acres 

(1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Tons (1,000s) Percent 

CEAP I 

Atlantic and Gulf 

Coastal Plains 2,245.6 16 12,148.9 84 21,968 60 14,705 40 

California Coastal 57.6 1 4,389.0 99 338 26 968 74 

East Central 3,305.1 35 6,007.3 65 31,649 79 8,363 21 

Lower Mississippi 

and Texas Gulf Coast 3,567.3 16 18,248.4 84 35,246 55 28,634 45 

North Central and 

Midwest 18,133.4 15 102,000.1 85 176,671 60 118,543 40 

Northeast 2,772.4 39 4,417.9 61 23,803 79 6,259 21 

Northern Plains 759.6 2 47,660.7 98 4,553 14 28,098 86 

Northwest 220.1 2 13,789.6 98 1,395 29 3,407 71 

South Central 1,516.9 25 4,617.7 75 15,267 62 9,455 38 

Southern and Central 

Plains 2,940.9 5 61,395.9 95 20,899 30 48,280 70 

Southwest 0 2,870.4 100 - 0 120 100 

National 35,519 11 277,546 89 331,789 55 266,834 45 

CEAP II 

Atlantic and Gulf 

Coastal Plains 2,006.5 15 11,818.2 85 22,070 62 13,350 38 

California Coastal 38.7 1 3,874.2 99 345 28 873 72 

East Central 3,257.8 32 6,908.4 68 31,965 77 9,745 23 

Lower Mississippi 

and Texas Gulf Coast 3,412.4 16 17,503.5 84 32,729 55 26,570 45 

North Central and 

Midwest 16,324.3 13 106,971.6 87 150,280 57 113,539 43 

Northeast 2,395.0 32 5,202.0 68 18,174 75 6,077 25 

Northern Plains 753.4 1 50,376.8 99 4,833 19 20,825 81 

Northwest 84.8 1 13,353.5 99 919 28 2,380 72 

South Central 1,455.7 29 3,651.6 71 15,011 71 6,139 29 

Southern and Central 

Plains 1,352.9 2 61,378.8 98 9,389 20 36,597 80 

Southwest 89.5 3 3,093.5 97 296 65 156 35 

National 31,171 10 284,132 90 286,012 55 236,252 45 
 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 135 

Table A-15. Wind Erosion Relative to Threshold by Region, CEAP I and CEAP II 

Region 

Cultivated Cropland 

Exceeding Threshold 

Cultivated Cropland 

Meeting Threshold 

Loss on Acres 

Exceeding Threshold 

Loss on Acres 

Meeting Threshold 

Acres 

(1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Tons (1,000s) Percent 

CEAP I 

Atlantic and Gulf Coastal 

Plains - 0 14,395 100 - 0 1,284 100 

California Coastal - 0 4,447 100 - 0 133 100 

East Central - 0 9,312 100 - 0 204 100 

Lower Mississippi and Texas 

Gulf Coast 373 2 21,443 98 2,836 29 6,849 71 

North Central and Midwest 2,653 2 117,481 98 20,770 24 67,120 76 

Northeast - 0 7,190 100 - 0 418 100 

Northern Plains 11,267 23 37,153 77 83,096 57 62,228 43 

Northwest 3,660 26 10,350 74 25,780 64 14,295 36 

South Central 64 1 6,070 99 342 7 4,458 93 

Southern and Central Plains 19,676 31 44,661 69 199,396 67 98,885 33 

Southwest 941 33 1,930 67 12,466 80 3,044 20 

National 38,634 12 274,431 88 344,686 57 258,919 43 

CEAP II 

Atlantic and Gulf Coastal 

Plains - 0 13,825 100 - 0 659 100 

California Coastal - 0 3,913 100 - 0 102 100 

East Central - 0 10,166 100 - 0 138 100 

Lower Mississippi and Texas 

Gulf Coast 537 3 20,379 97 5,054 52 4,737 48 

North Central and Midwest 1,875 2 121,421 98 13,809 21 52,996 79 

Northeast - 0 7,597 100 - 0 225 100 

Northern Plains 12,253 24 38,877 76 94,851 66 48,979 34 

Northwest 1,870 14 11,568 86 16,295 58 11,747 42 

South Central 106 2 5,001 98 610 20 2,379 80 

Southern and Central Plains 13,549 22 49,183 78 174,193 70 73,327 30 

Southwest 802 25 2,381 75 7,025 73 2,615 27 

National 30,994 10 284,309 90 311,836 61 197,904 39 
 

 

 

 

 

 

 

 

 

 

 

 

136 Conservation Effects Assessment Project 

Table A-16. Sediment Relative to Threshold by Region, CEAP I and CEAP II 

Region 

Cultivated Cropland 

Exceeding Threshold 

Cultivated Cropland 

Meeting Threshold 

Loss on Acres 

Exceeding Threshold 

Loss on Acres 

Meeting Threshold 

Acres 

(1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Tons (1,000s) Percent 

CEAP I 

Atlantic and Gulf 

Coastal Plains 1,949 14 12,445 86 11,329 71 4,713 29 

California Coastal 108 2 4,339 98 928 53 826 47 

East Central 2,694 29 6,619 71 20,777 85 3,561 15 

Lower Mississippi 

and Texas Gulf 6,067 28 15,749 72 39,696 80 9,690 20 

North Central 

Midwest 17,262 14 102,872 86 112,803 74 39,791 26 

Northeast 2,437 34 4,754 66 16,757 86 2,816 14 

Northern Plains 1,783 4 46,638 96 6,606 38 10,716 62 

Northwest 922 7 13,087 93 5,855 64 3,246 36 

South Central 2,172 35 3,963 65 14,319 83 2,868 17 

Southern and 

Central Plains 2,695 4 61,641 96 12,508 42 17,463 58 

Southwest 24 1 2,846 99 110 30 258 70 

National 38,113 12 274,952 88 241,689 72 95,946 28 

CEAP II 

Atlantic and Gulf 

Coastal Plains 1,663 12 12,162 88 11,341 72 4,310 28 

California Coastal 200 5 3,713 95 1,056 54 906 46 

East Central 2,868 28 7,298 72 21,079 85 3,627 15 

Lower Mississippi 

and Texas Gulf 5,104 24 15,812 76 28,860 74 9,999 26 

North Central 

Midwest 13,613 11 109,682 89 81,469 69 36,841 31 

Northeast 1,766 23 5,831 77 12,564 82 2,771 18 

Northern Plains 758 1 50,373 99 3,229 29 7,885 71 

Northwest 472 4 12,967 96 3,640 62 2,240 38 

South Central 1,666 33 3,442 67 11,101 83 2,218 17 

Southern and 

Central Plains 1,104 2 61,628 98 5,266 30 12,177 70 

Southwest 122 4 3,061 96 632 72 244 28 

National 29,335 9 285,968 91 180,237 68 83,218 32 
 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 137 

Table A-17. Surface Nitrogen Relative to Threshold by Region, CEAP I and CEAP II 

Region 

Cultivated Cropland 

Exceeding Threshold 

Cultivated Cropland 

Meeting Threshold 

Loss on Acres 

Exceeding Threshold 

Loss on Acres 

Meeting Threshold 

Acres 

(1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Tons (1,000s) Percent 

CEAP I 

Atlantic and Gulf Coastal 

Plains 294 2 14,101 98 4 22 15 78 

California Coastal 58 1 4,389 99 1 35 1 65 

East Central 1,478 16 7,834 84 22 60 15 40 

Lower Mississippi and Texas 

Gulf Coast 2,262 10 19,554 90 32 45 40 55 

North Central and Midwest 11,517 10 108,617 90 164 45 202 55 

Northeast 1,118 16 6,072 84 16 56 12 44 

Northern Plains 8,578 18 39,842 82 97 47 108 53 

Northwest 871 6 13,139 94 11 25 32 75 

South Central 1,387 23 4,748 77 18 59 12 41 

Southern and Central Plains 7,310 11 57,027 89 85 32 179 68 

Southwest 209 7 2,661 93 2 33 5 67 

National 35,084 11 277,981 89 452 42 621 58 

CEAP II 

Atlantic and Gulf Coastal 

Plains 481 3 13,344 97 7 31 16 69 

California Coastal 49 1 3,864 99 1 29 2 71 

East Central 1,770 17 8,396 83 30 63 18 37 

Lower Mississippi and Texas 

Gulf Coast 2,277 11 18,639 89 29 43 40 57 

North Central and Midwest 9,039 7 114,257 93 157 45 196 55 

Northeast 1,047 14 6,550 86 17 60 12 40 

Northern Plains 11,442 22 39,688 78 153 63 92 37 

Northwest 606 5 12,832 95 10 32 21 68 

South Central 1,326 26 3,781 74 21 69 9 31 

Southern and Central Plains 5,764 9 56,968 91 69 34 132 66 

Southwest 143 4 3,040 96 2 25 5 75 

National 33,946 11 281,357 89 497 48 541 52 
 

 

 

 

 

 

 

 

 

 

 

138 Conservation Effects Assessment Project 

TableA-18. Sediment-Transported Phosphorus Relative to Threshold by Region, CEAP I and CEAP II 

Region 

Cultivated Cropland 

Exceeding Threshold 

Cultivated Cropland 

Meeting Threshold 

Loss on Acres 

Exceeding Threshold 

Loss on Acres 

Meeting Threshold 

Acres 

(1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Tons (1,000s) Percent 

CEAP I 

Atlantic and Gulf Coastal 

Plains 1,543 11 12,852 89 5.0 57 3.7 43 

California Coastal 79 2 4,368 98 0.3 37 0.5 63 

East Central 2,396 26 6,917 74 11.1 81 2.6 19 

Lower Mississippi and Texas 

Gulf Coast 3,102 14 18,714 86 11.4 62 6.9 38 

North Central and Midwest 14,678 12 105,456 88 56.5 62 34.6 38 

Northeast 2,614 36 4,576 64 12.9 86 2.0 14 

Northern Plains 2,705 6 45,715 94 6.7 29 16.4 71 

Northwest 1,007 7 13,002 93 3.6 51 3.5 49 

South Central 1,660 27 4,475 73 5.0 71 2.1 29 

Southern and Central Plains 5,170 8 59,166 92 16.6 41 23.7 59 

Southwest 257 9 2,614 91 1.1 64 0.6 36 

National 35,211 11 277,854 89 130 57 97 43 

CEAP II 

Atlantic and Gulf Coastal 

Plains 1,606 12 12,218 88 6.0 65 3.3 35 

California Coastal 61 2 3,852 98 0.2 27 0.5 73 

East Central 2,743 27 7,424 73 12.4 82 2.7 18 

Lower Mississippi and Texas 

Gulf Coast 2,845 14 18,071 86 9.3 58 6.8 42 

North Central and Midwest 13,640 11 109,655 89 59.6 65 32.1 35 

Northeast 2,334 31 5,264 69 10.9 85 1.9 15 

Northern Plains 4,730 9 46,400 91 12.0 45 14.6 55 

Northwest 836 6 12,602 94 3.2 61 2.1 39 

South Central 1,221 24 3,886 76 4.4 72 1.7 28 

Southern and Central Plains 3,476 6 59,256 94 11.1 39 17.1 61 

Southwest 138 4 3,045 96 0.4 41 0.5 59 

National 33,630 11 281,673 89 129 61 83 39 
 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 139 

Table A-19. Subsurface Nitrogen Relative to Threshold, CEAP I and CEAP II 

Region 

Cultivated Cropland 

Exceeding Threshold 

Cultivated Cropland 

Meeting Threshold 

Loss on Acres 

Exceeding Threshold 

Loss on Acres 

Meeting Threshold 

Acres 

(1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Tons (1,000s) Percent 

CEAP I 

Atlantic and Gulf Coastal 

Plains 7,601 53 6,794 47 254 83 51 17 

California Coastal 1,553 35 2,894 65 86 86 14 14 

East Central 3,806 41 5,506 59 98 73 37 27 

Lower Mississippi and Texas 

Gulf Coast 10,256 47 11,560 53 242 75 81 25 

North Central and Midwest 32,828 27 87,306 73 785 61 498 39 

Northeast 3,404 47 3,786 53 123 84 23 16 

Northern Plains 4,746 10 43,674 90 133 56 105 44 

Northwest 2,545 18 11,465 82 111 80 28 20 

South Central 1,939 32 4,196 68 79 81 18 19 

Southern and Central Plains 5,036 8 59,301 92 173 61 112 39 

Southwest 1,068 37 1,802 63 74 95 4 5 

National 74,779 24 238,286 76 2,159 69 971 31 

CEAP II 

Atlantic and Gulf Coastal 

Plains 8,260 60 5,565 40 254 87 39 13 

California Coastal 1,311 34 2,602 66 70 87 10 13 

East Central 5,055 50 5,111 50 145 81 34 19 

Lower Mississippi and Texas 

Gulf Coast 9,886 47 11,030 53 273 79 74 21 

North Central and Midwest 38,371 31 84,925 69 1,025 68 491 32 

Northeast 3,769 50 3,828 50 126 83 25 17 

Northern Plains 9,988 20 41,142 80 285 69 128 31 

Northwest 2,684 20 10,754 80 115 85 21 15 

South Central 2,045 40 3,062 60 76 81 17 19 

Southern and Central Plains 6,784 11 55,948 89 202 65 108 35 

Southwest 764 24 2,419 76 29 89 4 11 

National 88,914 28 226,389 72 2,601 73 949 27 
 

 

 

 

 

 

 

 

 

 

 

140 Conservation Effects Assessment Project 

Table A-20. Soluble Phosphorus Relative to Threshold by Region, CEAP I and CEAP II 

Region 

Cultivated Cropland 

Exceeding Threshold 

Cultivated Cropland 

Meeting Threshold 

Loss on Acres 

Exceeding Threshold 

Loss on Acres 

Meeting Threshold 

Acres 

(1,000s) Percent Acres (1,000s) Percent Tons (1,000s) Percent Tons (1,000s) Percent 

CEAP I 

Atlantic and Gulf Coastal 

Plains 10,820 75 3,575 25 6 91 1 9 

California Coastal 285 6 4,161 94 1 74 0.4 26 

East Central 6,004 64 3,309 36 3 85 1 15 

Lower Mississippi and Texas 

Gulf Coast 14,634 67 7,182 33 10 92 1 8 

North Central and Midwest 31,059 26 89,074 74 18 63 11 37 

Northeast 4,328 60 2,862 40 3 85 0.5 15 

Northern Plains 468 1 47,953 99 0.2 10 2 90 

Northwest 1,351 10 12,659 90 1 68 0.4 32 

South Central 2,231 36 3,903 64 1 74 0.4 26 

Southern and Central Plains 1,297 2 63,039 98 1 28 2 72 

Southwest 432 15 2,439 85 0.4 77 0 23 

National 72,909 23 240,156 77 45 71 18 29 

CEAP II 

Atlantic and Gulf Coastal 

Plains 9,527 69 4,297 31 5 88 1 12 

California Coastal 665 17 3,248 83 1 80 0.2 20 

East Central 7,486 74 2,680 26 4 90 0.5 10 

Lower Mississippi and Texas 

Gulf Coast 16,233 78 4,683 22 11 94 1 6 

North Central and Midwest 40,064 32 83,232 68 25 69 11 31 

Northeast 4,478 59 3,119 41 2 83 1 17 

Northern Plains 748 1 50,382 99 0.3 12 2 88 

Northwest 877 7 12,561 93 1 58 0.4 42 

South Central 2,586 51 2,521 49 2 81 0.3 19 

Southern and Central Plains 1,405 2 61,327 98 1 22 2 78 

Southwest 292 9 2,891 91 0 88 0.1 12 

National 84,361 27 230,942 73 51 73 19 27 
 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 141 

Table A-21. Soil Carbon Relative to Threshold by Region, CEAP I and CEAP II 

Region 

Cultivated Cropland Exceeding 

Threshold 

Cultivated Cropland Meeting 

Threshold 

Acres (1000) Percent Acres (1000) Percent 

CEAP I 

Atlantic and Gulf Coastal Plains 1,494 10 12,900 90 

California Coastal 1,439 32 3,007 68 

East Central 1,150 12 8,162 88 

Lower Mississippi and Texas Gulf 

Coast 2,685 12 19,130 88 

North Central and Midwest 15,542 13 104,592 87 

Northeast 1,361 19 5,830 81 

Northern Plains 10,883 22 37,537 78 

Northwest 2,925 21 11,085 79 

South Central 1,283 21 4,852 79 

Southern and Central Plains 10,221 16 54,116 84 

Southwest 720 25 2,150 75 

National 49,703 16 263,362 84 

CEAP II 

Atlantic and Gulf Coastal Plains 2,083 15 11,742 85 

California Coastal 1,514 39 2,398 61 

East Central 1,381 14 8,785 86 

Lower Mississippi and Texas Gulf 

Coast 2,966 14 17,949 86 

North Central and Midwest 15,826 13 107,470 87 

Northeast 1,543 20 6,054 80 

Northern Plains 10,146 20 40,985 80 

Northwest 1,875 14 11,564 86 

South Central 1,514 30 3,593 70 

Southern and Central Plains 8,860 14 53,872 86 

Southwest 802 25 2,381 75 

National 48,511 15 266,792 85 
 

 

 

 

 

 

 

 

 

 

142 Conservation Effects Assessment Project 

Table A-22. Sediment Management on Cultivated Cropland by Region, CEAP I and CEAP II 

Region 

Sediment Management Level 

Low Moderate Moderately High High 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

CEAP I 

Atlantic and Gulf 

Coastal Plains 4,879 34 6,929 48 2,053 14 534 4 

California 

Coastal 2,334 52 1,597 36 35 1 481 11 

East Central 842 9 5,101 55 2,594 28 775 8 

Lower 

Mississippi and 

Texas Gulf 8,954 41 10,382 48 2,324 11 155 1 

North Central and 

Midwest 23,705 20 55,270 46 34,032 28 7,126 6 

Northeast 1,584 22 3,879 54 1,535 21 192 3 

Northern Plains 12,113 25 24,328 50 11,592 24 386 1 

Northwest 5,380 38 6,178 44 2,159 15 294 2 

South Central 1,410 23 3,574 58 1,140 19 10 0 

Southern and 

Central Plains 14,549 23 37,183 58 12,226 19 378 1 

Southwest 1,159 40 1,502 52 209 7 0 0 

National 76,910 25 155,923 50 69,900 22 10,332 3 

CEAP II 

Atlantic and Gulf 

Coastal Plains 2,924 21 7,511 54 2,600 19 790 6 

California 

Coastal 1,364 35 2,131 54 418 11 0 0 

East Central 491 5 5,029 49 3,579 35 1,067 10 

Lower 

Mississippi and 

Texas Gulf 7,187 34 10,029 48 3,150 15 550 3 

North Central and 

Midwest 13,343 11 48,244 39 45,138 37 16,570 13 

Northeast 1,007 13 3,215 42 2,618 34 756 10 

Northern Plains 9,217 18 26,912 53 12,921 25 2,081 4 

Northwest 2,988 22 5,268 39 4,405 33 777 6 

South Central 971 19 2,470 48 1,151 23 516 10 

Southern and 

Central Plains 8,108 13 28,861 46 23,061 37 2,701 4 

Southwest 1,186 37 1,540 48 449 14 8 0 

National 48,787 15 141,210 45 99,490 32 25,816 8 
 

 

 

 

 

 

 

 

 

 

 

 

Conservation Practices on Cultivated Cropland 143 

Table A-23. Nitrogen Management on Cultivated Cropland by Region, CEAP I and CEAP II 

Region 

Nitrogen Management Level 

Low Moderate Moderately High High 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

CEAP I 

Atlantic and Gulf 

Coastal Plains 3,279 23 973 7 5,539 38 4,603 32 

California Coastal 2,215 50 142 3 857 19 1,233 28 

East Central 2,918 31 571 6 3,789 41 2,034 22 

Lower Mississippi 

and Texas Gulf 

Coast 

6,584 30 1,796 8 6,098 28 7,338 34 

North Central and 

Midwest 16,191 13 15,276 13 46,315 39 42,352 35 

Northeast 1,957 27 427 6 2,680 37 2,127 30 

Northern Plains 2,174 4 772 2 13,038 27 32,436 67 

Northwest 3,303 24 267 2 2,899 21 7,541 54 

South Central 1,531 25 576 9 2,309 38 1,719 28 

Southern and 

Central Plains 7,293 11 1,275 2 21,963 34 33,805 53 

Southwest 1,176 41 139 5 737 26 819 29 

National 48,620 16 22,213 7 106,224 34 136,007 43 

CEAP II 

Atlantic and Gulf 

Coastal Plains 2,994 22 907 7 6,868 50 3,057 22 

California Coastal 1,969 50 235 6 863 22 846 22 

East Central 3,734 37 524 5 4,427 44 1,482 15 

Lower Mississippi 

and Texas Gulf 

Coast 

7,321 35 766 4 6,088 29 6,741 32 

North Central and 

Midwest 25,013 20 21,158 17 47,757 39 29,368 24 

Northeast 2,345 31 463 6 3,176 42 1,612 21 

Northern Plains 5,547 11 1,505 3 19,936 39 24,143 47 

Northwest 3,054 23 406 3 3,651 27 6,327 47 

South Central 1,343 26 584 11 1,900 37 1,281 25 

Southern and 

Central Plains 8,784 14 2,467 4 27,352 44 24,128 38 

Southwest 1,176 37 206 6 937 29 864 27 

National 63,279 20 29,220 9 122,954 39 99,850 32 
 

 

 

 

 

 

 

 

 

 

144 Conservation Effects Assessment Project 

Table A-24. Phosphorus Management on Cultivated Cropland by Region, CEAP I and CEAP II 

Region 

Phosphorus Management Level 

Low Moderate Moderately High High 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

Acres 

(1,000s) 

Percent 

Regional 

Acres 

CEAP I 

Atlantic and Gulf 

Coastal Plains 1,667 12 2,884 20 2,628 18 7,215 50 

California 

Coastal 802 18 713 16 124 3 2,808 63 

East Central 1,417 15 2,975 32 1,490 16 3,430 37 

Lower 

Mississippi and 

Texas Gulf 

805 4 2,642 12 4,330 20 14,038 64 

North Central and 

Midwest 7,000 6 20,477 17 25,112 21 67,545 56 

Northeast 1,420 20 1,298 18 651 9 3,821 53 

Northern Plains 202 0 1,218 3 2,889 6 44,111 91 

Northwest 1,175 8 1,037 7 1,040 7 10,758 77 

South Central 182 3 451 7 1,296 21 4,205 69 

Southern and 

Central Plains 954 1 3,058 5 7,215 11 53,111 83 

Southwest 521 18 377 13 312 11 1,660 58 

National 16,146 5 37,130 12 47,086 15 212,703 68 

CEAP II 

Atlantic and Gulf 

Coastal Plains 1,762 13 2,492 18 3,716 27 5,856 42 

California 

Coastal 739 19 852 22 376 10 1,946 50 

East Central 2,252 22 3,317 33 2,105 21 2,493 25 

Lower 

Mississippi and 

Texas Gulf 

1,371 7 3,974 19 4,120 20 11,451 55 

North Central and 

Midwest 10,460 8 33,569 27 24,504 20 54,763 44 

Northeast 1,226 16 1,613 21 1,257 17 3,501 46 

Northern Plains 1,072 2 3,703 7 5,353 10 41,002 80 

Northwest 1,342 10 880 7 1,128 8 10,089 75 

South Central 375 7 774 15 951 19 3,008 59 

Southern and 

Central Plains 1,994 3 5,330 8 9,553 15 45,855 73 

Southwest 550 17 400 13 486 15 1,748 55 

National 23,140 7 56,902 18 53,549 17 181,711 58 
 

 

 

Conservation Practices on Cultivated Cropland 145 

Table A-25. Sediment Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II 

Region SVI-R Sediment 

Management Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

Atlantic and Gulf Coastal Plains 

High 180 1 15 176 1 15 

High - - - 36 20 2 

Moderately High 49 27 4 24 14 4 

Moderate 99 55 7 64 37 7 

Low 32 18 4 51 29 2 

Moderately High 1,124 8 122 1,461 11 101 

High 62 5 9 190 13 8 

Moderately High 173 15 16 272 19 18 

Moderate 685 61 77 712 49 59 

Low 204 18 20 286 20 16 

Moderate 1,976 14 197 2,932 21 159 

High 30 1 4 226 8 10 

Moderately High 389 20 27 557 19 36 

Moderate 934 47 99 1,629 56 82 

Low 624 32 67 519 18 31 

Low 11,115 77 956 9,256 67 489 

High 442 4 30 338 4 36 

Moderately High 1,443 13 116 1,746 19 111 

Moderate 5,211 47 485 5,105 55 246 

Low 4,019 36 325 2,067 22 96 

California Coastal 

High - - 101 3 4 

High - - - - -

Moderately High - - - 44 43 3 

Moderate - - - 57 57 1 

Low - - - - -

Moderately High 50 1 2 174 4 8 

High - - - - - -

Moderately High - - - 43 25 2 

Moderate - - - 103 59 4 

Low 50 100 2 27 16 2 

Moderate 1,102 25 25 647 17 28 

High - - - - - -

Moderately High 8 1 1 - - -

Moderate 236 21 10 326 50 16 

Low 858 78 14 320 50 12 

Low 3,295 74 84 2,992 76 167 

High 481 15 1 -

Moderately High 27 1 2 331 11 8 

Moderate 1,361 41 45 1,645 55 106 

Low 1,426 43 36 1,017 34 53 
 

 

 

146 Conservation Effects Assessment Project 

Table A-25. Sediment Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R Sediment 

Management Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

East Central 

High 1,629 17 168 2,250 22 172 

High 118 7 7 396 18 29 

Moderately High 502 31 56 812 36 62 

Moderate 928 57 94 986 44 75 

Low 81 5 11 57 3 6 

Moderately High 2,737 29 299 2,982 29 215 

High 245 9 25 196 7 14 

Moderately High 956 35 108 1,348 45 97 

Moderate 1,264 46 131 1,305 44 96 

Low 271 10 35 132 4 8 

Moderate 1,347 14 116 2,085 21 136 

High 188 14 12 242 12 21 

Moderately High 374 28 32 570 27 40 

Moderate 668 50 61 1,164 56 68 

Low 117 9 11 108 5 7 

Low 3,600 39 331 2,849 28 217 

High 224 6 20 232 8 16 

Moderately High 761 21 78 849 30 70 

Moderate 2,241 62 195 1,574 55 115 

Low 374 10 38 193 7 16 

Lower Mississippi and Texas Gulf Coast 

High 419 2 86 590 3 51 

High 3 1 1 64 11 4 

Moderately High 173 41 38 279 47 27 

Moderate 231 55 43 220 37 18 

Low 12 3 4 27 5 2 

Moderately High 2,053 9 255 2,117 10 161 

High 29 1 8 183 9 12 

Moderately High 745 36 96 752 36 58 

Moderate 855 42 112 922 44 73 

Low 424 21 39 261 12 18 

Moderate 11,941 55 882 7,786 37 485 

High 57 0 7 148 2 9 

Moderately High 741 6 69 776 10 55 

Moderate 5,742 48 423 3,611 46 232 

Low 5,402 45 383 3,251 42 189 

Low 7,402 34 597 10,423 50 693 

High 66 1 9 155 1 12 

Moderately High 666 9 68 1,344 13 98 

Moderate 3,553 48 310 5,276 51 352 

Low 3,116 42 210 3,648 35 231 
 

 

 

Conservation Practices on Cultivated Cropland 147 

Table A-25. Sediment Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R Sediment 

Management Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

North Central and Midwest 

High 15,178 13 1,199 19,377 16 687 

High 2,233 15 152 5,076 26 170 

Moderately High 7,038 46 567 10,175 53 354 

Moderate 5,111 34 414 3,704 19 144 

Low 795 5 66 423 2 19 

Moderately High 23,585 20 1,737 24,668 20 870 

High 1,550 7 99 4,238 17 148 

Moderately High 8,262 35 631 10,764 44 393 

Moderate 10,562 45 773 8,129 33 286 

Low 3,211 14 234 1,536 6 43 

Moderate 19,444 16 1,232 13,923 11 484 

High 1,010 5 54 1,260 9 50 

Moderately High 4,938 25 308 4,667 34 165 

Moderate 8,909 46 583 6,729 48 223 

Low 4,587 24 287 1,267 9 46 

Low 61,927 52 3,897 65,329 53 2,164 

High 2,333 4 149 5,996 9 197 

Moderately High 13,794 22 901 19,533 30 669 

Moderate 30,688 50 1,929 29,683 45 984 

Low 15,112 24 918 10,118 15 314 

Northeast 

High 1,834 26 238 2,426 32 204 

High 63 3 10 336 14 31 

Moderately High 589 32 79 1,023 42 96 

Moderate 984 54 124 735 30 62 

Low 198 11 25 333 14 15 

Moderately High 1,913 27 241 2,116 28 178 

High 43 2 11 99 5 12 

Moderately High 405 21 56 695 33 67 

Moderate 975 51 116 1,077 51 78 

Low 489 26 58 244 12 21 

Moderate 1,014 14 107 950 13 89 

High 8 1 1 61 6 7 

Moderately High 92 9 17 245 26 29 

Moderate 625 62 63 562 59 44 

Low 289 28 26 83 9 9 

Low 2,429 34 302 2,105 28 195 

High 78 3 11 260 12 22 

Moderately High 448 18 63 656 31 60 

Moderate 1,295 53 153 842 40 88 

Low 608 25 75 347 17 25 
 

 

148 Conservation Effects Assessment Project 

Table A-25. Sediment Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R Sediment 

Management Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

Northern Plains 

High 3,128 6 110 2,990 6 87 

High 33 1 1 345 12 10 

Moderately High 957 31 34 974 33 27 

Moderate 1,779 57 62 1,518 51 46 

Low 359 11 13 152 5 4 

Moderately High 11,155 23 331 9,857 19 242 

High 60 1 3 648 7 13 

Moderately High 3,669 33 116 3,817 39 87 

Moderate 5,156 46 149 5,097 52 131 

Low 2,270 20 63 295 3 11 

Moderate 8,232 17 236 8,896 17 201 

High 41 1 1 229 3 7 

Moderately High 1,557 19 48 1,899 21 47 

Moderate 3,710 45 114 5,755 65 122 

Low 2,924 36 73 1,013 11 25 

Low 25,905 54 841 29,388 57 682 

High 252 1 10 859 3 21 

Moderately High 5,409 21 174 6,230 21 152 

Moderate 13,683 53 452 14,543 49 362 

Low 6,560 25 205 7,757 26 147 

Northwest 

High 3,296 24 227 3,858 29 128 

High 42 1 3 372 10 8 

Moderately High 850 26 62 1,633 42 70 

Moderate 1,403 43 100 1,478 38 43 

Low 1,001 30 62 374 10 7 

Moderately High 3,183 23 233 3,436 26 134 

High 77 2 2 173 5 6 

Moderately High 363 11 23 1,113 32 43 

Moderate 1,389 44 105 1,273 37 49 

Low 1,353 43 103 876 26 36 

Moderate 558 4 63 779 6 32 

High 31 6 1 - - -

Moderately High 83 15 4 231 30 8 

Moderate 269 48 31 347 45 17 

Low 175 31 27 201 26 7 

Low 6,973 50 525 5,366 40 253 

High 144 2 7 232 4 11 

Moderately High 861 12 67 1,428 27 65 

Moderate 3,117 45 217 2,170 40 106 

Low 2,851 41 234 1,537 29 71 
 

 

Conservation Practices on Cultivated Cropland 149 

Table A-25. Sediment Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R Sediment 

Management Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

South Central 

High 20 0 2 211 4 8 

High - - - 31 15 1 

Moderately High - - - 91 43 4 

Moderate 20 100 2 49 23 2 

Low - - - 40 19 1 

Moderately High 1,657 27 65 1,667 33 85 

High - - - 113 7 5 

Moderately High 405 24 15 586 35 37 

Moderate 998 60 41 766 46 34 

Low 255 15 9 202 12 9 

Moderate 2,458 40 88 1,898 37 104 

High 5 0 1 198 10 12 

Moderately High 472 19 14 218 11 14 

Moderate 1,407 57 49 947 50 45 

Low 574 23 24 535 28 33 

Low 1,999 33 77 1,331 26 82 

High 5 0 1 174 13 4 

Moderately High 264 13 11 255 19 17 

Moderate 1,149 57 40 708 53 49 

Low 581 29 25 193 15 12 

Southern and Central Plains 

High 1,393 2 66 1,539 2 46 

High 24 2 1 228 15 3 

Moderately High 515 37 22 739 48 24 

Moderate 775 56 37 538 35 18 

Low 78 6 6 34 2 1 

Moderately High 6,018 9 253 9,340 15 261 

High 104 2 4 597 6 18 

Moderately High 1,678 28 70 4,748 51 123 

Moderate 3,680 61 155 3,781 40 112 

Low 557 9 24 214 2 8 

Moderate 6,194 10 244 4,701 7 157 

High 32 1 1 112 2 6 

Moderately High 1,147 19 43 1,839 39 61 

Moderate 3,757 61 147 2,126 45 70 

Low 1,258 20 53 624 13 20 

Low 50,732 79 2,052 47,151 75 1,339 

High 219 0 10 1,764 4 49 

Moderately High 8,886 18 368 15,736 33 443 

Moderate 28,971 57 1,125 22,415 48 660 

Low 12,656 25 549 7,236 15 187 
 

 

150 Conservation Effects Assessment Project 

Table A-25. Sediment Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R Sediment 

Management Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

Southwest 

High 68 2 6 14 0 1 

High - - - - - -

Moderately High - - - - - -

Moderate 38 56 4 14 100 1 

Low 30 44 2 - - -

Moderately High 247 9 19 349 11 12 

High - - - - - -

Moderately High 58 24 3 127 36 3 

Moderate 74 30 8 113 32 7 

Low 115 47 8 109 31 2 

Moderate 269 9 16 185 6 12 

High - - - - - -

Moderately High 15 6 1 - - -

Moderate 162 60 10 73 39 6 

Low 92 34 5 112 61 6 

Low 2,287 80 149 2,636 83 110 

High - - - 8 0 1 

Moderately High 136 6 9 322 12 13 

Moderate 1,229 54 58 1,341 51 53 

Low 922 40 82 965 37 43 
 

 

 

Conservation Practices on Cultivated Cropland 151 

Table A-26. Nitrogen Management and Soil Vulnerability Index—Leaching (SVI-L) by Region, CEAP I and 

CEAP II 

Region SVI-L 

Rating 

Nitrogen Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

Atlantic and Gulf Coastal Plains 

High 6,694 47 4,069 29 

High 2,007 30 154 967 24 49 

Moderately High 2,668 40 210 1,954 48 107 

Moderate 312 5 25 332 8 18 

Low 1,707 25 101 817 20 54 

Moderately High 3,661 25 4,760 34 

High 1,233 34 107 1,086 23 48 

Moderately High 1,338 37 127 2,305 48 106 

Moderate 310 8 28 353 7 14 

Low 781 21 61 1,016 21 38 

Moderate 3,799 26 3,938 28 

High 1,308 34 136 809 21 55 

Moderately High 1,403 37 185 2,045 52 118 

Moderate 351 9 32 189 5 11 

Low 737 19 99 895 23 73 

Low 240 2 1,058 8 

High 56 23 6 195 18 13 

Moderately High 130 54 14 563 53 36 

Moderate - 0 0 33 3 3 

Low 54 22 5 267 25 21 

California Coastal 

High 621 14 1,369 35 

High 163 26 8 219 16 12 

Moderately High 152 25 7 380 28 33 

Moderate 14 2 1 79 6 5 

Low 291 47 10 691 50 41 

Moderately High 388 9 386 10 

High 36 9 2 66 17 3 

Moderately High 59 15 1 108 28 5 

Moderate 30 8 1 51 13 1 

Low 263 68 3 161 42 15 

Moderate 2,278 51 1,543 39 

High 912 40 8 371 24 12 

Moderately High 438 19 9 218 14 10 

Moderate 63 3 1 105 7 5 

Low 865 38 22 849 55 41 

Low 1,160 26 615 16 

High 122 11 3 191 31 4 

Moderately High 208 18 8 156 25 7 

Moderate 34 3 2 - 0 0 

Low 796 69 25 269 44 13 
 

 

 

152 Conservation Effects Assessment Project 

Table A-26. Nitrogen Management and Soil Vulnerability Index—Leaching (SVI-L) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-L 

Rating 

Nitrogen Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

East Central 

High 1,756 19 1,081 11 

High 496 28 42 119 11 12 

Moderately High 656 37 58 469 43 35 

Moderate 129 7 12 111 10 7 

Low 475 27 47 382 35 23 

Moderately High 705 8 1,339 13 

High 192 27 20 115 9 12 

Moderately High 279 40 31 715 53 50 

Moderate 73 10 7 68 5 5 

Low 161 23 17 441 33 31 

Moderate 6,728 72 5,980 59 

High 1,306 19 134 955 16 58 

Moderately High 2,785 41 279 2,405 40 183 

Moderate 362 5 38 277 5 25 

Low 2,275 34 214 2,343 39 160 

Low 123 1 1,767 17 

High 40 32 4 294 17 23 

Moderately High 69 56 9 837 47 62 

Moderate 7 6 1 68 4 8 

Low 8 6 1 568 32 46 

Lower Mississippi and Texas Gulf Coast 

High 4,463 20 6,374 30 

High 1,529 34 103 2,192 34 141 

Moderately High 851 19 79 1,932 30 130 

Moderate 266 6 20 168 3 12 

Low 1,816 41 130 2,083 33 130 

Moderately High 11,773 54 7,781 37 

High 4,242 36 316 3,034 39 180 

Moderately High 3,471 29 280 1,981 25 135 

Moderate 1,060 9 57 255 3 14 

Low 3,000 25 253 2,511 32 155 

Moderate 4,772 22 4,258 20 

High 1,386 29 152 888 21 86 

Moderately High 1,363 29 173 1,324 31 104 

Moderate 380 8 57 183 4 12 

Low 1,643 34 176 1,862 44 143 

Low 808 4 2,502 12 

High 180 22 7 626 25 47 

Moderately High 413 51 9 851 34 44 

Moderate 89 11 3 159 6 9 

Low 126 16 5 865 35 48 
 

 

 

Conservation Practices on Cultivated Cropland 153 

Table A-26. Nitrogen Management and Soil Vulnerability Index—Leaching (SVI-L) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-L 

Rating 

Nitrogen Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

North Central and Midwest 

High 42,935 36 49,186 40 

High 15,473 36 1018 11,756 24 378 

Moderately High 15,642 36 1015 18,278 37 608 

Moderate 5,870 14 349 9,623 20 293 

Low 5,950 14 369 9,529 19 311 

Moderately High 20,061 17 14,715 12 

High 6,880 34 447 3,975 27 127 

Moderately High 8,059 40 509 5,582 38 194 

Moderate 2,897 14 162 2,405 16 87 

Low 2,225 11 142 2,752 19 91 

Moderate 54,003 45 48,928 40 

High 18,602 34 1355 10,783 22 397 

Moderately High 21,340 40 1518 19,592 40 727 

Moderate 6,241 12 406 7,331 15 261 

Low 7,820 14 542 11,221 23 397 

Low 3,133 3 10,467 8 

High 1,397 45 92 2,853 27 85 

Moderately High 1,273 41 100 4,304 41 144 

Moderate 267 9 24 1,798 17 60 

Low 196 6 17 1,511 14 45 

Northeast 

High 1,055 15 1,167 15 

High 457 43 46 229 20 18 

Moderately High 282 27 33 605 52 46 

Moderate 29 3 6 116 10 6 

Low 286 27 32 216 19 25 

Moderately High 692 10 1,026 14 

High 268 39 33 290 28 27 

Moderately High 255 37 29 469 46 40 

Moderate 48 7 6 53 5 6 

Low 120 17 16 214 21 21 

Moderate 5,304 74 3,746 49 

High 1,335 25 136 601 16 56 

Moderately High 2,095 39 264 1,497 40 140 

Moderate 348 7 42 202 5 21 

Low 1,527 29 223 1,447 39 147 

Low 140 2 1,658 22 

High 66 47 9 492 30 32 

Moderately High 48 34 7 605 36 37 

Moderate 1 1 1 93 6 11 

Low 24 17 5 468 28 33 
 

 

154 Conservation Effects Assessment Project 

Table A-26. Nitrogen Management and Soil Vulnerability Index—Leaching (SVI-L) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-L 

Rating 

Nitrogen Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

Northern Plains 

High 12,828 26 13,880 27 

High 7,623 59 227 6,114 44 118 

Moderately High 4,058 32 128 5,257 38 108 

Moderate 362 3 9 460 3 9 

Low 785 6 25 2,049 15 49 

Moderately High 4,362 9 5,659 11 

High 2,945 67 77 2,817 50 58 

Moderately High 1,080 25 33 2,061 36 44 

Moderate 151 3 4 172 3 3 

Low 187 4 4 608 11 11 

Moderate 28,080 58 27,756 54 

High 19,703 70 596 13,557 49 332 

Moderately High 7,060 25 251 10,791 39 284 

Moderate 259 1 8 729 3 20 

Low 1,057 4 41 2,679 10 70 

Low 3,150 7 3,835 7 

High 2,165 69 71 1,655 43 43 

Moderately High 841 27 35 1,826 48 51 

Moderate - 0 0 143 4 3 

Low 144 5 9 210 5 9 

Northwest 

High 3,024 22 2,269 17 

High 1,573 52 107 887 39 44 

Moderately High 554 18 49 550 24 30 

Moderate 111 4 6 93 4 6 

Low 785 26 76 738 33 33 

Moderately High 651 5 259 2 

High 248 38 14 71 27 6 

Moderately High 91 14 14 86 33 9 

Moderate 11 2 3 52 20 3 

Low 301 46 29 50 19 5 

Moderate 9,866 70 10,244 76 

High 5,498 56 334 5,141 50 167 

Moderately High 2,186 22 154 2,770 27 102 

Moderate 132 1 15 238 2 12 

Low 2,050 21 209 2,094 20 101 

Low 468 3 667 5 

High 222 47 15 228 34 11 

Moderately High 67 14 7 244 37 10 

Moderate 12 3 2 23 4 1 

Low 167 36 14 172 26 7 
 

 

Conservation Practices on Cultivated Cropland 155 

Table A-26. Nitrogen Management and Soil Vulnerability Index—Leaching (SVI-L) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-L 

Rating 

Nitrogen Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

South Central 

High 836 14 464 9 

High 411 49 11 115 25 6 

Moderately High 146 17 6 123 26 8 

Moderate 31 4 2 109 24 5 

Low 248 30 7 116 25 9 

Moderately High 1,290 21 1,038 20 

High 390 30 16 357 34 18 

Moderately High 525 41 27 269 26 19 

Moderate 61 5 3 127 12 3 

Low 314 24 17 285 27 18 

Moderate 1,689 28 1,359 27 

High 305 18 17 417 31 24 

Moderately High 848 50 35 632 47 33 

Moderate 40 2 3 76 6 3 

Low 496 29 15 234 17 17 

Low 2,320 38 2,246 44 

High 613 26 21 391 17 19 

Moderately High 790 34 24 875 39 50 

Moderate 444 19 10 271 12 13 

Low 473 20 18 708 32 34 

Southern and Central Plains 

High 16,869 26 10,784 17 

High 7,748 46 340 3,638 34 98 

Moderately High 6,460 38 260 4,440 41 145 

Moderate 215 1 11 574 5 20 

Low 2,446 14 130 2,132 20 75 

Moderately High 2,330 4 1,708 3 

High 948 41 43 587 34 15 

Moderately High 936 40 41 764 45 29 

Moderate 46 2 4 26 2 1 

Low 398 17 16 330 19 15 

Moderate 39,522 61 45,308 72 

High 22,177 56 835 17,728 39 454 

Moderately High 12,544 32 484 20,000 44 511 

Moderate 889 2 42 1,690 4 60 

Low 3,912 10 183 5,890 13 198 

Low 5,616 9 4,932 8 

High 2,932 52 120 2,175 44 79 

Moderately High 2,023 36 81 2,148 44 78 

Moderate 125 2 4 177 4 7 

Low 536 10 21 432 9 18 
 

 

156 Conservation Effects Assessment Project 

Table A-26. Nitrogen Management and Soil Vulnerability Index—Leaching (SVI-L) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-L 

Rating 

Nitrogen Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

Southwest 

High 432 15 638 20 

High 80 19 6 287 45 14 

Moderately High 167 39 7 170 27 11 

Moderate 52 12 2 68 11 4 

Low 132 31 10 114 18 8 

Moderately High 142 5 63 2 

High 76 53 5 - 0 0 

Moderately High 66 47 4 6 10 1 

Moderate - 0 0 42 67 1 

Low - 0 0 15 23 2 

Moderate 2,103 73 2,356 74 

High 637 30 40 560 24 22 

Moderately High 481 23 37 694 29 26 

Moderate 85 4 6 97 4 4 

Low 899 43 58 1,005 43 34 

Low 194 7 126 4 

High 26 13 2 17 14 3 

Moderately High 22 11 3 67 53 2 

Moderate 1 <1 1 - 0 0 

Low 145 75 9 42 33 3 
 

 

 

 

 

Conservation Practices on Cultivated Cropland 157 

Table A-27. Phosphorus Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II 

Region SVI-R 

Phosphorus 

Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

Atlantic and Gulf Coastal Plains 

High 180 1 176 1 

High 107 59 8 77 44 6 

Moderately High 20 11 2 45 25 4 

Moderate 13 7 2 40 23 3 

Low 40 22 3 14 8 2 

Moderately High 1,124 8 1,461 11 

High 510 45 47 499 34 33 

Moderately High 251 22 29 374 26 29 

Moderate 261 23 34 371 25 26 

Low 102 9 12 217 15 13 

Moderate 1,976 14 2,932 21 

High 1,084 55 118 1,032 35 71 

Moderately High 320 16 31 1,071 37 47 

Moderate 404 20 35 534 18 25 

Low 168 9 13 295 10 16 

Low 11,115 77 9,256 67 

High 5,514 50 512 4,248 46 237 

Moderately High 2,037 18 180 2,226 24 116 

Moderate 2,206 20 197 1,547 17 92 

Low 1,357 12 67 1,235 13 44 

California Coastal 

High - 0 101 3 

High - 0 0 44 43 3 

Moderately High - 0 0 - 0 0 

Moderate - 0 0 57 57 1 

Low - 0 0 - 0 0 

Moderately High 50 1 174 4 

High - 0 0 129 74 4 

Moderately High - 0 0 - 0 0 

Moderate 21 43 1 10 6 1 

Low 29 57 1 35 20 3 

Moderate 1,102 25 647 17 

High 535 49 16 265 41 11 

Moderately High 24 2 2 34 5 2 

Moderate 513 47 6 167 26 8 

Low 29 3 1 180 28 7 

Low 3,295 74 2,992 76 

High 2,273 69 51 1,508 50 81 

Moderately High 100 3 6 342 11 20 

Moderate 178 5 12 618 21 38 

Low 745 23 15 524 18 28 
 

 

 

 

 

158 Conservation Effects Assessment Project 

Table A-27. Phosphorus Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R 

Phosphorus 

Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

East Central 

High 1,629 17 2,250 22 

High 580 36 63 416 18 37 

Moderately High 173 11 17 508 23 40 

Moderate 640 39 61 705 31 53 

Low 236 14 27 622 28 42 

Moderately High 2,737 29 2,982 29 

High 769 28 83 660 22 41 

Moderately High 509 19 53 592 20 43 

Moderate 1,042 38 118 1,113 37 84 

Low 416 15 45 617 21 47 

Moderate 1,347 14 2,085 21 

High 576 43 47 642 31 32 

Moderately High 168 13 14 444 21 32 

Moderate 372 28 38 491 24 41 

Low 230 17 17 508 24 31 

Low 3,600 39 2,849 28 

High 1,504 42 130 774 27 58 

Moderately High 640 18 52 562 20 43 

Moderate 921 26 98 1,007 35 76 

Low 535 15 51 506 18 40 

Lower Mississippi and Texas Gulf Coast 

High 419 2 590 3 

High 157 37 22 69 12 10 

Moderately High 141 34 29 110 19 10 

Moderate 97 23 28 350 59 25 

Low 24 6 7 61 10 6 

Moderately High 2,053 9 2,117 10 

High 895 44 81 565 27 46 

Moderately High 417 20 61 517 24 36 

Moderate 568 28 83 858 41 64 

Low 173 8 30 177 8 15 

Moderate 11,941 55 7,786 37 

High 8,273 69 585 4,728 61 298 

Moderately High 2,449 21 187 1,512 19 91 

Moderate 904 8 86 1,068 14 69 

Low 315 3 24 478 6 27 

Low 7,402 34 10,423 50 

High 4,713 64 363 6,089 58 395 

Moderately High 1,323 18 121 1,981 19 149 

Moderate 1,073 14 87 1,698 16 109 

Low 292 4 26 655 6 40 
 

 

 

 

 

Conservation Practices on Cultivated Cropland 159 

Table A-27. Phosphorus Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R 

Phosphorus 

Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

North Central and Midwest 

High 15,178 13 19,377 16 

High 7,597 50 607 7,540 39 267 

Moderately High 3,068 20 248 3,417 18 120 

Moderate 3,390 22 260 6,930 36 244 

Low 1,123 7 84 1,489 8 56 

Moderately High 23,585 20 24,668 20 

High 12,610 53 960 10,554 43 364 

Moderately High 4,740 20 324 4,210 17 160 

Moderate 4,562 19 338 7,261 29 254 

Low 1,674 7 115 2,643 11 92 

Moderate 19,444 16 13,923 11 

High 11,278 58 718 6,154 44 216 

Moderately High 4,233 22 254 2,767 20 96 

Moderate 3,040 16 197 3,664 26 126 

Low 894 5 63 1,338 10 46 

Low 61,927 52 65,329 53 

High 36,061 58 2349 30,515 47 999 

Moderately High 13,072 21 777 14,111 22 469 

Moderate 9,486 15 573 15,713 24 529 

Low 3,309 5 198 4,990 8 167 

Northeast 

High 1,834 26 2,426 32 

High 968 53 116 995 41 81 

Moderately High 167 9 24 381 16 36 

Moderate 358 19 49 608 25 50 

Low 342 19 49 443 18 37 

Moderately High 1,913 27 2,116 28 

High 892 47 104 981 46 73 

Moderately High 284 15 41 360 17 29 

Moderate 346 18 48 442 21 45 

Low 391 20 48 333 16 31 

Moderate 1,014 14 950 13 

High 603 59 58 553 58 51 

Moderately High 46 5 5 178 19 18 

Moderate 194 19 23 103 11 11 

Low 171 17 21 117 12 9 

Low 2,429 34 2,105 28 

High 1,358 56 157 972 46 91 

Moderately High 154 6 28 339 16 33 

Moderate 399 16 60 461 22 38 

Low 517 21 57 333 16 33 
 

 

 

 

160 Conservation Effects Assessment Project 

Table A-27. Phosphorus Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R 

Phosphorus 

Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

Northern Plains 

High 3,128 6 2,990 6 

High 2,937 94 105 2,433 81 70 

Moderately High 191 6 5 300 10 11 

Moderate - 0 0 207 7 5 

Low - 0 0 50 2 1 

Moderately High 11,155 23 9,857 19 

High 10,739 96 309 8,499 86 200 

Moderately High 327 3 18 796 8 25 

Moderate 90 1 4 360 4 10 

Low - 0 0 201 2 7 

Moderate 8,232 17 8,896 17 

High 7,458 91 211 7,172 81 160 

Moderately High 553 7 17 910 10 17 

Moderate 221 3 8 719 8 21 

Low - 0 0 95 1 3 

Low 25,905 54 29,388 57 

High 22,977 89 738 22,898 78 517 

Moderately High 1,818 7 60 3,347 11 83 

Moderate 907 4 32 2,418 8 61 

Low 202 1 11 725 2 21 

Northwest 

High 3,296 24 3,858 29 

High 3,046 92 202 3,530 91 114 

Moderately High 114 3 10 138 4 7 

Moderate 66 2 6 90 2 5 

Low 71 2 9 100 3 2 

Moderately High 3,183 23 3,436 26 

High 2,631 83 183 2,631 77 93 

Moderately High 128 4 12 255 7 13 

Moderate 226 7 18 218 6 12 

Low 197 6 20 332 10 16 

Moderate 558 4 779 6 

High 329 59 28 495 63 21 

Moderately High 72 13 9 190 24 7 

Moderate 83 15 13 38 5 2 

Low 74 13 13 57 7 2 

Low 6,973 50 5,366 40 

High 4,752 68 334 3,434 64 157 

Moderately High 726 10 50 546 10 35 

Moderate 662 9 69 533 10 31 

Low 833 12 72 853 16 30 
 

 

 

 

Conservation Practices on Cultivated Cropland 161 

Table A-27. Phosphorus Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R 

Phosphorus 

Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

South Central 

High 20 <1 211 4 

High 10 49 1 63 30 2 

Moderately High 10 51 1 70 33 2 

Moderate - 0 0 42 20 2 

Low - 0 0 36 17 2 

Moderately High 1,657 27 1,667 33 

High 990 60 38 919 55 47 

Moderately High 541 33 20 289 17 17 

Moderate 74 4 4 270 16 15 

Low 53 3 3 189 11 6 

Moderate 2,458 40 1,898 37 

High 1,853 75 59 1,247 66 72 

Moderately High 408 17 18 243 13 15 

Moderate 167 7 9 324 17 14 

Low 30 1 2 85 4 3 

Low 1,999 33 1,331 26 

High 1,352 68 47 779 59 51 

Moderately High 337 17 17 349 26 17 

Moderate 211 11 10 138 10 7 

Low 99 5 3 65 5 7 

Southern and Central Plains 

High 1,393 2 1,539 2 

High 1,187 85 57 1,046 68 30 

Moderately High 113 8 5 317 21 10 

Moderate 38 3 2 96 6 4 

Low 55 4 2 80 5 2 

Moderately High 6,018 9 9,340 15 

High 4,918 82 206 6,912 74 187 

Moderately High 761 13 32 1,451 16 40 

Moderate 264 4 12 846 9 29 

Low 75 1 3 131 1 5 

Moderate 6,194 10 4,701 7 

High 5,098 82 200 3,755 80 123 

Moderately High 770 12 31 581 12 23 

Moderate 318 5 12 208 4 8 

Low 8 <1 1 157 3 3 

Low 50,732 79 47,151 75 

High 41,908 83 1693 34,142 72 960 

Moderately High 5,570 11 214 7,203 15 189 

Moderate 2,438 5 103 4,181 9 142 

Low 816 2 42 1,625 3 48 
 

 

 

 

162 Conservation Effects Assessment Project 

Table A-27. Phosphorus Management and Soil Vulnerability Index—Runoff (SVI-R) by Region, CEAP I and 

CEAP II—Cont. 

Region SVI-R 

Phosphorus 

Management 

Level 

CEAP I CEAP II 

Acres 

(1,000s) Percent Count Acres (1,000s) Percent Count 

Southwest 

High 68 2 14 <1 

High 68 100 6 14 100 1 

Moderately High - 0 0 - 0 0 

Moderate - 0 0 - 0 0 

Low - 0 0 - 0 0 

Moderately High 247 9 349 11 

High 205 83 14 321 92 7 

Moderately High 22 9 2 25 7 3 

Moderate 1 <1 1 1 <1 1 

Low 19 8 2 2 <1 1 

Moderate 269 9 185 6 

High 181 68 10 115 62 6 

Moderately High - 0 0 46 25 3 

Moderate 8 3 1 3 2 1 

Low 79 29 5 21 11 2 

Low 2,287 80 2,636 83 

High 1,206 53 91 1,298 49 61 

Moderately High 289 13 11 414 16 12 

Moderate 368 16 19 396 15 17 

Low 423 19 28 528 20 20 
 

 

Conservation Practices on Cultivated Cropland 163 

APPENDIX 3. MANAGEMENT LEVELS CRITERIA 

Throughout the report, cultivated cropland is categorized by the level of sediment, nitrogen, and 

phosphorus management being applied to allow comparison of conservation treatment between 

the two survey periods. Cultivated cropland acres are placed into one of four management 

levels—high, moderately high, moderate, and low. The criteria are based on an Avoid, Control, 

and Trap approach to reducing sediment losses, and a Rate, Method, and Timing approach to 

reducing nutrient losses from cropland. The following provides an overview of the criteria for 

categorizing sediment, nitrogen, and phosphorus management. 

Sediment Management Levels: 

1. High: At least one practice from each category with no practice counting twice. 

a. Avoid: 

i. All crops in the rotation are in conservation tillage (continuous no-till or reduced 

tillage) 

b. Control: 

i. At least one structural practice in overland flow or concentrated flow control 

categories (e.g., terrace, contouring, or grassed waterway), or 

ii. A high biomass conservation crop rotation (i.e., a crop residue score of 2 or 

more). 

c. Trap: 

i. At least one structural practice to trap potential losses (e.g., filter or buffer), or 

ii. A field border structural practice with a minimum of 30 feet in width and placed 

to intercept flow from cropped area. 

2. Moderately High: At least one practice from two of the categories with no practice counting 

twice. 

a. Avoid: 

i. All crops in the rotation are in conservation tillage (continuous no-till or reduced 

tillage) 

b. Control: 

i. At least one structural practice in overland flow or concentrated flow control 

categories (e.g., terrace, contouring, or grassed waterway), or 

ii. A high biomass conservation crop rotation (i.e., a crop residue score of 2 or 

more) if all crops are in conservation tillage. 

c. Trap: 

i. At least one structural practice to trap potential losses (e.g., filter or buffer), or 

ii. If all crops are in conservation tillage, a field border structural practice with a 

minimum of 30 feet in width and placed to intercept flow from cropped area can 

be substituted for filter or buffer trapping practice. 

3. Moderate: At least one practice from any category. 

a. Avoid: 

i. All crops in the rotation are under conservation tillage (continuous no-till or 

reduced tillage), 

b. Control: 

i. At least one structural practice in overland flow or concentrated flow control 

categories (e.g., terrace, contouring, or grassed waterway), or 

ii. A high biomass conservation crop rotation (i.e., a crop residue score of 2 or 

more). 
 

 

 

 

 

 

 

 

164 Conservation Effects Assessment Project 

c. Trap: 

i. At least one trapping practice such as a filter or buffer, or 

ii. A Field Border can be substituted if it is minimum of 30 feet in width and 

intercepts flow from cropped area. 

4. Low: 

a. At least one crop in the rotation under conventional tillage, and 

b. No avoid, control, or trap practices are applied 

Nutrient Management: 

For nitrogen and phosphorus management, management levels are based primarily on rate, 

method, and timing of nutrient application: 

Rate: Four rate classes are based on the average annual per acre nutrient application for the crop 

rotation: 

1. Nitrogen: 

a. Low: Rotational average of 75 pounds or less per acre annually. 

b. Moderate: Rotational average of greater than 75 pounds and less than or equal to 90 

pounds per acre annually. 

c. Moderately High: Rotational average of greater than 90 pounds and less than or equal to 

120 pounds per acre annually. 

d. High: Rotational average of more than 120 pounds per acre annually. 

2. Phosphorus 

a. Low: Rotational average of 20 pounds or less per acre annually. 

b. Moderate: Rotational average of greater than 20 pounds and less than or equal to 35 

pounds per acre annually. 

c. Moderately High: Rotational average of greater than 35 pounds and less than or equal to 

50 pounds per acre annually. 

d. High: Rotational average more than 50 pounds per acre annually 

Method: Three method classes are based on the level of incorporation of the applied nutrient for 

the crop rotation: 

1. All applications are incorporated within 48 hours through tillage, injection, knifing, or banding. 

Fertigation is considered incorporation since the water moves the nutrients from surface into 

subsurface. 

2. Some applications are incorporated within 48 hours. 

3. No applications are incorporated within 48 hours. 

Post-plant and fall applications to perennials and winter annuals are exempted from the method 

assessment. Post-plant applications on actively growing crops with full surface coverage have 

very low loss risk through surface and subsurface pathways, especially with late winter/early 

spring top dressing of winter annuals (e.g., wheat). 

Timing: Two timing classes are based on fall and winter applications (beginning of September 

to end of February) for the crop rotation: 

1. No fall or winter application. Fall manure applications are considered acceptable for all crops in 

the rotation, however, winter manure applications are not acceptable for any crop in the rotation, 

including winter annuals and perennials. All non-manure applications are acceptable for winter 

annuals and perennials regardless of season. 
 

 

Conservation Practices on Cultivated Cropland 165 

2. At least one fall or winter application. 

Nitrogen Management Levels: 

High: 

i. Rate class is low, or 

ii. Rate class is moderate, all or some applications are incorporated, and there are no fall or winter 

applications. 

Moderately High: 

i. Rate class is moderate, or 

ii. Rate class is moderately high, all applications are incorporated, and there are no fall or winter 

applications. 

Moderate: 

i. Rate class is moderately high, and all or some applications are incorporated. 

Low: 

i. Rate class is moderately high, and no applications are incorporated, or 

ii. Rate class is high. 

Phosphorus Management Levels: 

High: 

i. No phosphorus is applied, or 

ii. Rate class is low, and all applications are incorporated, or 

iii. Rate class is low, some applications are incorporated, and there are no fall or winter applications, 

or 

iv. Rate class is moderate, all applications are incorporated, and there are no fall or winter 

applications, or 

v. Rate class is low, and all applications are post-plant applications on winter annuals or perennials. 

Moderately High: 

i. Rate class is low, some applications are incorporated, and there are fall or winter applications, or 

ii. Rate class is low, and no applications are incorporated, or 

iii. Rate class is moderate, and all applications are incorporated, or 

iv. Rate class is moderate, and all applications are post-plant applications on winter annuals or 

perennials. 

Moderate: 

i. Rate class is moderate, and some or none of the applications are incorporated, or 

ii. Rate class is moderately high, and all applications are incorporated, or 

iii. Rate class is moderately high, and all applications are post-plant applications on winter annuals or 

perennials. 

Low: 

i. Rate class is moderately high and some or none of the applications are incorporated, or 

ii. Rate class is high.