Soil Quality and Conservation Tillage in the Palouse and Dryland Farming Regions of the Pacific Northwest

摘要

Include a problem statement, objectives, brief methods, quantitative results, and the significance of your findings. The ab:should be no more than 250 words long. Soil quality was assessed at several long-term dryland cropping systems research sites in eastern Washington and northern Idaho to further define management practices that build rather than degrade soil. The objective was to characterize soil quality changes over time as affected by tillage and cropping system at sites near Colfax, Ritzville, and Lind, WA and Genesee, ID. We found that soil quality changes during the transition from tillage-based farming to no-till are less dramatic and more variable in the low precipitation (150- to 300- mm annual) zone compared to the higher precipitation (300- to 550- mm annual) zone. Tillage impacts soil quality more than surface residue management or crop rotation. Soil organic carbon (SOC) slowly increased in long-term no-till and approached or exceeded that of nearby undisturbed native soil. Long-term no-till also increased the proportion of aggregates in the larger sized soil fractions. We also see that long-term no-till results in microbial community changes and an increase in the fungahbacterial ratio. Data from these long-term experiments willallow us to better assess the productivity and quality of soils in the Palouse and other dryland cropping regions of the Inland Pacific Northwest. This information will allow identification of soil quality parameters that can be used in the developmentof best management practices for conserving soil quality and enhancing crop production.