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United States Department of Agriculture

Agricultural Research Service

Title: Soil Quality Changes with Conservation Reserve Program (Crp) Take-Out

Authors
item Gewin, Virginia
item Kennedy, Ann
item Veseth, Roger - WASHINGTON STATE UNIV.
item Miller, Baird - WASHINGTON STATE UNIV.

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 1, 1997
Publication Date: N/A

Interpretive Summary: Conservation Reserve Program (CRP) lands in eastern Washington may return to dryland cropping production as of 1995. Permanent ground cover has reduced erosion potential; however, soil quality parameters must be evaluated to maintain the benefits of CRP in years to come. Three types of trials were conducted: conventional tillage/summer fallow take-out (CSF), conventional tillage/spring plant take-out (CSP), and direct-seed/spring plant take-out (DSP). Soil quality was examined after take-out to determine the effects of using a variety of tillage and residue management practices within each trial. Differences in the eastern Washington sites included annual rainfall between 23 to 36 cm and the soil organic matter between 1.06% to 2.60%. Biomass, readily-mineralized carbon (RMC), organic matter content (OM), dehydrogenase, pH, moisture, bulk density, and aggregate stability were monitored. RMC and pH were lower after one year in the CSF and CSP plots when compared to CRP grass. The direct-seed samples at the DSP trials were most similar to CRP grass with respect to pH, dehydrogenase, biomass and RMC as compared to the CSF sites. No differences in bulk density or organic matter content were found between CRP grass and treatments in any trial after one or two years of take-out. Some differences were seen in aggregate stability between tillage treatments and CRP grass, but no treatment effect was substantial over all sites. Disturbance caused changes in soil quality parameters, with the greatest changes found immediately after take-out. For dryland cropping areas of eastern Washington, direct-seed systems more effectively preserved soil quality characteristics than other more intensive tillage systems.

Technical Abstract: Conservation Reserve Program (CRP) lands in eastern Washington may return to dryland cropping production as of 1995. Permanent ground cover has reduced erosion potential; however, soil quality parameters must be evaluated to maintain the benefits of CRP in years to come. Three types of trials were conducted: conventional tillage/summer fallow take-out (CSF), conventional tillage/spring plant take-out (CSP), and direct-seed/spring plant take-out (DSP). Soil quality was examined after take-out to determine the effects of using a variety of tillage and residue management practices within each trial. Differences in the eastern Washington sites included annual rainfall between 23 to 36 cm and the soil organic matter between 1.06 percent to 2.60 percent. Biomass,readily-mineralized carbon (RMC), organic matter content (OM), dehydrogenase, pH, moisture, bulk density, and aggregate stability were monitored. RMC and pH were lower after one year in the CSF and CSP plots when compared to CRP grass. The direct-seed samples at the DSP trials were most similar to CRP grass with respect to pH, dehydrogenase, biomass and RMC as compared to the CSF sites. No differences in bulk density or organic matter content were found between CRP grass and treatments in any trial after one or two years of take-out. Some differences were seen in aggregate stability between tillage treatments and CRP grass, but no treatment effect was substantial over all sites. Disturbance caused changes in soil quality parameters, with the greatest changes found immediately after take-out. For dryland cropping areas of eastern Washington, direct-seed systems more effectively preserved soil quality characteristics than other more intensive tillage systems.

Last Modified: 10/1/2014
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