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NATURAL RESOURCES CONSERVATION SERVICE

CONSERVATION PRACTICE STANDARD

CONSERVATION CROP ROTATION

(Ac.)

CODE 328

DEFINITION

A planned sequence of crops grown on the 

same ground over a period of time (i.e. the 

rotation cycle).

PURPOSE

This practice is applied to support one or more 

of the following purposes:

• Reduce sheet, rill and wind erosion.

• Maintain or increase soil health and 

organic matter content.

• Reduce water quality degradation due to 

excess nutrients.

• Improve soil moisture efficiency.

• Reduce the concentration of salts and 

other chemicals from saline seeps.

• Reduce plant pest pressures.

• Provide feed and forage for domestic 

livestock.

• Provide food and cover habitat for wildlife, 

including pollinator forage, and nesting.

CONDITIONS WHERE PRACTICE APPLIES

This practice applies to all cropland where at 

least one annually-planted crop is included in 

the crop rotation.

CRITERIA

General Criteria Applicable to All Purposes 

Crops shall be grown in a planned sequence 

as outlined in Plans and Specifications. The 

crop rotation shall include a minimum of two 

different crops. For purposes of these criteria

a cover crop is considered a different crop.

Where applicable, plan suitable crop 

substitutions when the planned crop cannot be 

planted due to weather, soil conditions, or 

other local situations.

Additional Criteria to Reduce Sheet, Rill 

and Wind Erosion

Select crops, a tillage system, and cropping 

sequences that will produce sufficient and

timely quantities of biomass or crop residue 

which, in conjunction with other practices in the 

management system, will reduce sheet, rill and 

wind erosion to the planned soil loss objective.

Determine the amount of biomass or crop 

residue needed by using current approved 

erosion prediction technology.

Additional Criteria to Maintain or Increase 

Soil Health and Organic Matter Content

Grow crops that will produce a positive trend in 

the Organic Matter (OM) subfactor value over 

the life of the rotation, as determined by the 

Soil Conditioning Index. Make appropriate 

adjustments for additions to or subtractions 

from biomass.

Additional Criteria to Reduce Water Quality 

Degradation Due to Excess Nutrients

To recover excess nutrients from the soil 

profile, use crops with:

• Quick germination and root system 

formation,

• A rooting depth sufficient to reach the 

nutrients not removed by the previous 

crop, and 

• Nutrient requirements that readily utilize 

the excess nutrients.

• Credit nutrients provided by legumes and 

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September 2014

Conservation practice standards are reviewed periodically and updated if needed. To obtain 

the current version of this standard, contact your Natural Resources Conservation Service 

State Office or visit the Field Office Technical Guide.
328 - 2

manure/compost.

Additional Criteria to Improve Soil Moisture 

Efficiency

Select crops, varieties of crops, and the 

sequence of crops based on local climate 

patterns, soil conditions, irrigation water 

availability, and an approved water balance 

procedure.

Additional Criteria to Reduce the 

Concentration of Salts and Other 

Chemicals from Saline Seeps

Select crops to be grown in the recharge area 

of saline seeps that have rooting depths and 

water requirements adequate to fully utilize all 

available soil water. Do not use summer 

fallow. Use an approved water balance 

procedure to determine crop selection and 

sequence.

If excess subsoil moisture exists below the 

rooting depth of crops commonly grown in the 

recharge area, establish deep-rooted perennial 

crops for the number of years needed to dry 

the soil profile.

Select crops with a tolerance to salinity levels 

that matches the salinity of the discharge area.

Additional Criteria to Reduce Plant Pest 

Pressures

Design the crop sequence to suppress the 

pest(s) lifecycle of concern, which may include 

weeds, insects, and pathogens. Use land grant 

university or industry standards to determine a 

suitable crop sequence.

Additional Criteria to Provide Feed and 

Forage for Domestic Livestock

Select crops that balance the feed supply with 

livestock numbers. Determine the required 

amount of selected crops using an approved 

forage-livestock balance procedure.

Additional Criteria to Provide Food and 

Habitat for Wildlife, Including Pollinator 

Forage, and Nesting

Select the crops and crop management 

activities that provide either food or cover for 

the targeted wildlife species using an approved 

habitat evaluation procedure. 

CONSIDERATIONS

When used in combination with NRCS 

Conservation Practice (CPS) Stripcropping 

(Code 585), the crop sequence should be 

consistent with the stripcropping design.

Soil compaction can be reduced by adjusting 

crop rotations to include deep rooting crops 

with deep roots that extend to and penetrate 

compacted soil layers.

Where improving water use efficiency on deep 

soils is a concern, rotating or combining deeprooted crops with shallow rooted crops can 

help utilize all available water in the soil profile.

Select crops that have the potential to provide 

larger amounts of biologically fixed nitrogen.

Considerations to Reduce Water Quality 

Degradation Due to Excess Nutrients:

• Include perennial or annual legume crops 

in the rotation to provide nitrogen for the 

non-legume crops, especially in fields 

where manure applications are restricted 

by high or excessive soil phosphorus or 

potassium levels.

• Use carbon/nitrogen ratio of 25:1 to 35:1 

crop residues returned to the soil 

throughout the rotation. This ratio can 

build the soil’s capacity to provide slowrelease N to crops while minimizing N 

leaching.

Considerations to Increase Cropping 

System Diversity

Minimize the fallow years in the rotation and 

where the climate and soils are favorable 

establish cover crops during the fallow periods. 

For crop diversity, the planned crop sequence 

should contain different crop types; for 

example a mix of the following: warm season 

grass; warm season broadleaf; cool season 

grass; cool season broadleaf.

• A two-crop sequence that contains a warm 

season and a cool season crop;

• A three-crop sequence that contains warm 

and cool season crops. The same crop 

species should not be grown in successive 

years in the same field.

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• A four-crop sequence that contains two 

different crop types, neither should occupy 

more than half of the sequence;

• Longer crop sequences (four or more 

years) are more effective with no more 

than two consecutive years with the same 

crop;

• In tropical regions or regions with distinct 

wet and dry seasons (Mediterranean 

climate), grass crops should alternate with 

broadleaf crops.

Additional Considerations to Reduce Sheet 

and Rill or Wind Erosion.

When used in combination with NRCS CPSs 

for Residue and Tillage Management (Codes 

329 and 345), selection of high-residue 

producing crops and varieties, use of cover 

crops and adjustment of plant density and row 

spacing can enhance production of the kind, 

amount, and distribution of residue needed.

When used in combination with NRCS CPSs 

Stripcropping (Code 585) or Contour Buffer 

Strips (Code 332) on steeper slopes, the 

effectiveness of each practice is significantly 

enhanced by inclusion of the other practice(s) 

in the conservation system.

Crop damage by wind erosion can be reduced 

with this practice by selecting crops that are 

tolerant to abrasion from windblown soil or 

tolerant to high wind velocity. 

If crops sensitive to wind erosion damage are 

grown, the potential for plant damage can be 

reduced by crop residue management, field 

windbreaks, herbaceous wind barriers, 

intercropping, or other methods of wind 

erosion control.

Additional Considerations to Improve Soil 

Health

Consider including perennial sod crops with 

deep or extensive fibrous root systems to build 

organic matter throughout the soil profile. 

In semiarid regions, where seasonal fallow is 

often used to store moisture in the soil for a 

subsequent crop, consider leaving sufficient 

residues to protect the soil surface during 

fallow, or growing a shallow-rooted cover crop 

that allows deep moisture storage. Reduce 

the intensity of tillage and increase soil surface 

coverage with vegetation and crop residues.

The effects of this practice can be enhanced 

by utilizing animal wastes, green manure crops 

(cover crops), or applying non-synthetic 

mulches to supplement the biomass produced 

by crops in the rotation.

Other considerations for soil health/organic 

matter management include:

• For at least one-third of the crop 

sequence (time basis) include highbiomass annual or perennial crops. 

• Utilize cover crops and high residue 

production crops comprising at least 

one-half of the rotation sequence. 

• For rotations dominated by lowresidue crops, such as vegetables, 

include sufficient cover crops and high 

residue crops for one-half the rotation.

Additional Considerations to Reduce Plant 

Pest Pressures

Consider lengthening the rotation to include 

several years of perennial cover to break pest 

life cycles.

Use a mix of crops from at least three different 

plant families, and allow three years or longer 

between successive plantings of production 

crops within the same family.

Enhance biological pest control by designing 

the crop rotation to: 

• Include flowering annuals or perennials 

that provide food and habitat for beneficial 

insects, such as buckwheat, clovers, or 

Phacelia. 

• Include plant species that release into the 

soil natural substances that suppress plant 

pathogens, nematodes or pests 

(biofumigation). 

• Include crops in the rotation that provide 

habitat for natural enemies of pests. 

• Retain bolting or flowering crops after

harvest to provide food for beneficial 

insects.

Additional Considerations to Provide Food 

and Cover Habitat for Wildlife, Including 

Pollinator Forage, and Nesting

Crop residues may be a valuable food source 

for wintering wildlife where winter browse is 

sparse. Leaving several rows unharvested 

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around the edges of the field, or planting 

borders of various forbs will provide protection 

and/or food for overwintering wildlife and for 

beneficial insects and pollinators.

Crop plantings may be developed to benefit 

particular communities, species, or life stages 

of wildlife. Food plots or crops for wildlife can 

provide part of a habitat restoration, an initial 

food and cover for wildlife until food and cover 

producing vegetation becomes established.

Retaining bolting or flowering crops after 

harvest may provide beneficial insects with an 

important food source.

Careful consideration should be given to 

pesticides applied to crops raised for wildlife, 

particularly if nesting habitat or pollinator 

forage species are present.

When insect-pollinated crops are part of the 

rotation, planting the insect-pollinated crop no 

more than 800 feet from their previous location 

may help maintain local populations of native 

bees that have become established because 

of the presence of that crop.

To maintain stable pollinator and beneficial 

insect populations, ensure that the same 

overall density of floral resources is maintained 

from year-to-year. For example two years of 

flower-rich plantings, followed by a year of only 

grasses, will cause a rapid decline in pollinator 

populations. Such a scenario is undesirable. 

PLANS AND SPECIFICATIONS

Develop plans and specifications for each field 

or treatment unit according to the Criteria and 

Operation and Maintenance requirements of 

this standard. Specifications shall describe the 

requirements to apply this practice to achieve 

the intended purpose. Record the following 

specification components in an approved 

Conservation Crop Rotation, 328, 

Implementation Requirements document. The 

following items will be documented as a 

minimum.

• Field number and acres,

• Purpose(s) of the crop rotation,

• The sequence of crops to be grown, 

• The crop types to be grown,

• Tillage type and times,

• Length of time each crop/crop type will be 

grown in the rotation, and 

• Total length of rotation

• Suitable crop substitutions to address 

weather, soil conditions, market, or other 

situations that may prevent the planned 

crop from being planted.

OPERATION AND MAINTENANCE

Rotations shall provide for acceptable 

substitute crops in case of crop failure or shift 

in planting intentions for weather related or 

economic reasons. Acceptable substitutes are 

crops having similar properties that will 

accomplish the purpose of the original crop.

Evaluate the rotation and the crop sequence to 

determine if the planned system is meeting the 

planned purposes.

REFERENCES

Green, B., D. Kaminski, B. Rapp, M. Celetti, D. 

Derksen, L. Juras, and D. Kelner. 2005. 

Principles and practices of crop rotation.

Saskatchewan Agriculture and Food.

Karlen, D.L., E.G. Hurley, S.S. Andrews, C.A. 

Cambardella, D.W. Meek, M.D. Duffy, and A.P. 

Mallorino. 2006. Crop rotation effects on soil 

quality at three northern corn/soybean belt 

locations. Agron. J. 98:484-495.

Liebig, M.A., D.L. Tanaka, J.M. Krupinsky, 

S.D. Merrill, and J.D. Hanson. 2007. Dynamic 

cropping systems: Contributions to improve 

agroecosystem sustainability. Agron. J. 

99:899-903.

Sherrod, L.A., G.A. Peterson, D.G. Westfall, 

and L.R. Ahuja. 2003. Cropping intensity 

enhances soil organic carbon and nitrogen in a 

no-till agroecosystem. Agron. J. 67:1533-

1543.

USDA-AMS National Organic Program Final 

Rule 7 CFR Part 205. 

26TUhttp://www.ams.usda.gov/AMSv1.0/nopU 26T.

USDA, NRCS. 2014. Revised Universal Soil 

Loss Equation Version 2 (RUSLE2) website: 

Washington, DC. 

26Thttp://www.nrcs.usda.gov/wps/portal/nrcs/main

/national/technical/tools/rusle2/ 26T

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USDA, NRCS. 2014. Wind Erosion Prediction 

System (WEPS) website: Washington, DC. 

26Thttp://www.nrcs.usda.gov/wps/portal/nrcs/main

/national/technical/tools/weps/26T

USDA, NRCS. 2011. National Agronomy 

Manual, 4th Ed. Washington, DC. 

26Thttp://directives.sc.egov.usda.gov/viewerFS.as

px?hid=2960626T

USDA, NRCS. 2014. Preventing or mitigating 

potential negative impacts of pesticides on 

pollinators using IPM and other conservation 

practices. Nat. Agron. Tech Note 9. 

Washington, DC. 

26Thttp://directives.sc.egov.usda.gov/OpenNonW

ebContent.aspx?content=34828.wba26T

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