|Stubbs, T - WASHINGTON STATE UNIV|
Submitted to: Society for Ecological Restoration Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 24, 2007
Publication Date: September 24, 2007
Citation: Stubbs, T.L., Kennedy, A.C. 2007. Soil Quality Changes with No-Till Management and Conservation Reserve Program (CRP) Take-out. Society for Ecological Restoration Abstracts-Northwest Chapter Regional Conference. Technical Abstract: Agricultural producers in eastern Washington are adopting no-till farming in an effort to reduce soil erosion. In addition, lands returning to production after enrollment in the Conservation Reserve Program (CRP) must be managed in order to maintain improvements in soil quality. The soil characteristics monitored were readily mineralizable carbon, organic matter, dehydrogenase enzyme activity, pH, aggregate size distribution and microbial community structure. Our first objective was to assess soil quality at long-term dryland cropping systems sites to further define management practices that are soil building rather than degrading. Soil quality changes were characterized over time as affected by no-till versus traditional tillage-based management systems. Soil organic carbon slowly increased in long-term no-till and approached or exceeded that of nearby undisturbed sites. Long-term no-till also increased the proportion of aggregates in larger sized soil fractions. Also a greater proportion of the carbon in no-till was stored in the larger size aggregates and thus protected from loss due to wind erosion. The second objective was to assess changes in soil quality with conservation and conventional practices in lands that were eligible to return to production after ten years of enrollment in CRP. Readily mineralizable carbon and pH were lower after one year in conventionally-tilled plots compared to CRP grassland. Soils from no-till fields were more like CRP grassland soils with respect to pH, dehydrogenase and readily mineralizable carbon than conventionally tilled soils. No-till management enhances soil quality in conventionally managed soils, and maintains soil quality in lands previously enrolled in the CRP program.