Northwest Columbia Plateau PM10 Project Objective 7: Identify Sustainable Farming Practices for the Columbia Plateau by Measuring Changes in Soil Quality Title: Soil Quality Changes with No-till Management Adoption for Wind Erosion Control

of Research Findings Soil quality parameters were assessed at several long-term dryland cropping systems research sites in eastern Washington to further define management practices that are soil building rather than degrading. The objective was to characterize soil quality changes 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 the larger sized soil fractions. Also, no-till stored a greater proportion of the carbon in the larger size aggregates thus protecting more of the carbon from loss due to wind erosion. Soil quality changes during the transition to no-till are less perceptible and are more variable in the low (150– to 300– mm annually) precipitation zones compared to the higher (300– to 550– mm annually) precipitation zones. The addition of irrigation water to Lind soils appears to shorten the transition time. The soil quality of continuous winter wheat-burn-plow treatment is being degraded compared to direct seed treatments. Slight differences in soil quality among residue treatments are evident. In a long-term no-till drill study we found no differences in the soil properties tested in these two sites. With direct seeding, the lower disturbance has more of an impact on soil quality measurements than surface residue management. Lignin content of various crops was in the order hard white spring wheat < winter wheat < spring barley. The C:N ratios of spring wheat cultivars separated by market class. Cultivar relationships differed; however, additional analyses may be needed to predict straw decomposition potential. Data from these long-term experiments will allow us to better assess the productivity and quality of soils in the dryland cropping region of the Inland Pacific Northwest. Objective The objective of this research is to characterize biological, physical and chemical soil quality parameters and monitor their changes over time in minimum tillage, no-till or direct seed seeding systems as affected by soil disturbance, crop species and management systems. This will allow the identification of soil quality parameters that can be used in the development of best management practices for conserving soil quality and enhancing crop production.