Decreased Land Use Intensity Improves Surface Soil Quality on Marginal Lands

Authors

• Lidong Li, USDA, Agricultural Research Service, Lincoln, NebraskaFollow
• Virginia L. Jin, USDA, Agricultural Research Service, Lincoln, NebraskaFollow
• Timothy Kettler, USDA, Agricultural Research Service, Lincoln, Nebraska
• Douglas L. Karlen, USDA, Agricultural Research Service, Ames, IowaFollow
• Márcio R. Nunes, USDA, Agricultural Research Service, Ames, Iowa
• R. Michael Lehman, USDA, Agricultural Research Service, Brookings, South Dakota
• Jane M. F. Johnson, USDA, Agricultural Research Service, Morris, Minnesota
• Maysoon M. Mikha, USDA, Agricultural Research Service, Akron, Colordado

ORCID IDs

Li https://orcid.org/0000-0001-5420-260X

Jin https://orcid.org/0000-0003-4146-8497

Nunes https://orcid.org/0000-0002-3674-279X

Johnson https://orcid.org/0000-0002-1687-4007

Mikha https://orcid.org/0000-0003-2264-1661

Document Type

Article

Date of this Version

2021

Citation

Agrosystems, Geosciences & Environment (2021) 4: e20226

doi: 10.1002/agg2.20226

Comments

United States government work. Public domain

Abstract

The Conservation Reserve Program (CRP) has been a major factor in land transitions out of intensive row-crop management on marginally productive lands in the central United States. While CRP can protect these more environmentally sensitive lands against erosion and potential nutrient loss, information on how CRP affects soil quality over time is limited. Using a chronosequence with 0–40 yr of CRP conversion history, we evaluated soil quality under different land use intensities (CRP, pasture, row crop) using the Soil Management Assessment Framework (SMAF). Effects of slope classes (higher [14–25%] and lower [2–14%]) and soil depth (0–120 cm) were also evaluated. Our results show that the soils were functioning at 84% and 78% of their theoretical capacity under CRP and row crop, respectively. Conversion to CRP enhanced overall soil quality by increasing soil biological, physical, and chemical attributes, but soil nutrient availability decreased due to the absence of fertilizer application. Increasing soil organic C (SOC) enhanced overall soil quality because of its impact on soil biological, physical, chemical, and nutrient conditions. Conversion to CRP will likely have greater benefits for more environmentally sensitive soils (i.e., higher slope) as demonstrated by structural equation modeling. Land use effects were also depth dependent, with more prominent effects within the 0-to-5-cm than the 5-to-15-cm depth increment. Overall, our methods focused on key soil quality indicators, confirmed ecological benefits of CRP conversion, and provided guidance for improved and simplified land management recommendations.