U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Wind Erosion and Water Conservation Research: Lubbock, TX
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                                    Software
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Plains Area Lubbock, Texas Cropping Systems Research Laboratory Wind Erosion and Water Conservation Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Zobeck, Teddyitem
                                            Van Pelt, Robert

                                                         - *Scott*item
                                            Acosta-Martinez, Veronicaitem
                                            BRONSON, KEVIN - TAMUitem
                                            Upchurch, Danitem
                                            CROWNOVER, JAMES - NRCS
  Submitted to: World Congress of Soil Science
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 7/9/2006
                                    Publication  Date: 7/15/2006
                                    Citation: Zobeck, T.M., Van Pelt, R.S., Acosta Martinez, V., Bronson, K., Upchurch, D.R., Crownover, J. 2006. The soil conditioning index as a soil quality tool:  Comparisons with measured soil properties. World Congress of Soil Science. July 9-15, 2006. Philadelphia, Pennsylvania.Interpretive Summary:
                                Technical Abstract: Governmental policy makers and other land managers are continuously evaluating the effects of land management practices on soil, air, and water resources.  Assessment tools are often developed and used for this purpose. The United States Department of Agriculture, Natural Resources Conservation Service (NRCS) has proposed the Soil Conditioning Index (SCI) to predict the consequences of management actions on the state of soil organic carbon (SOC), a soil quality indicator. The SCI is used to determine enrollment eligibility for the relatively new USDA conservation program known as the Conservation Security Program (CSP), an important voluntary program that provides financial and technical assistance to promote the conservation and improvement of soil, water, air, energy, plant and animal life, and other conservation purposes on Tribal and private working lands.  The SCI predicts qualitative changes in organic matter and considers biomass produced and returned to the soil, the influence of climate on organic matter decay, and the influence of tillage practices and erosion.  In this project, we relate SCI with measured SOC, particulate organic matter carbon content (POM-C), nitrogen content, and wet aggregate stability (WAS) in semiarid, thermic, sandy soils under a variety of land management practices. Forty-six study sites were identified in the Southern High Plains of west Texas where long-term native rangelands or conservation grasslands were adjacent to cropped land.  Management systems included native rangeland, conservation grassland, cotton, wheat, wheat-cotton rotation, sorghum, high residue sorghum/forages, sunflowers, and black eyed peas.  The cropland included dryland and irrigated crops.  Three replications were sampled on each site.  Samples were collected at depths 0 to10-cm and 10 to 20-cm.  Carbon and nitrogen was measured with a CN analyzer and bulk density, measured by the core method, was used to determine the values of selected soil variables on a mass basis.  Correlation coefficients of SCI with C mass (Mg ha-1), N mass (Mg ha-1), POM-C (Mg ha-1), and WAS (%) were 0.22, 0.43, 0.56 and 0.59, respectively.  All native rangelands and conservation grasslands and no-tillage fields (dryland and irrigated) had positive SCI values, which indicates increasing organic matter levels. In contrast, all of the conventionally-tilled cotton fields had negative SCI values, indicating decreasing organic matter levels. Fields with a wheat cover crop that was subsequently chemically killed before cotton planting had positive and negative SCI values.  The SCI does seem to be a useful soil quality assessment tool but it must be used with caution. The SCI was not related to total SOC in this study, but did show significant correlations with POM-C and WAS. The SCI successfully identified fields with the highest levels of SOC and when no-tillage management was practiced but had difficulty in distinguishing among fields when the same cover crop was used with limited tillage (terminated wheat cover in cotton). Additional research is needed to adjust the SCI sub-factors to better relate the index with SOC.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov