Submitted to: Columbia Plateau Wind Erosion Research Reports
Publication Type: Other
Publication Acceptance Date: 1/20/2002
Publication Date: 6/20/2002
Citation: Kennedy, A.C., Schillinger, W.F., Stubbs, T.L. Soil quality changes with no-till management adoption for wind erosion control. Schillinger, W.L. editor. Washington State University, Pullman, WA. Northwest Columbia Plateau Wind Erosion/Air Quality Project Research Reports 2001. 2002. p. 72-76. Interpretive Summary: Effectively managing the transition period between tillage and no-tillage may well be one of the most important management decisions for the initial success of no-till systems, or the continued use of no-till on a long-term basis. Understanding the changing soil characteristics during this transition period is key to effective management. Soil quality parameters were assessed at several long-term dryland cropping systems research sites in eastern Washington. The objective was to characterize soil quality changes over time as affected by no-till versus traditional tillage-based management systems. Organic carbon increased over time with long-term no-till. Changes in the microbial community and other soil quality parameters such as pH, electrical conductivity and microbial enzyme activity were variable in their response. Soil quality changes during the transition to no-till take longer and are more variable in the low (240-to 300¿mm annual) precipitation zones compared to the higher (300-to 550-mm annual) precipitation zones. Future data from these long-term experiments will allow us to better assess the health or quality of soils in the dryland cropping region of the Inland Pacific Northwest to aid farmers in the transition to no-till cropping.
Technical Abstract: Soil quality parameters are being assessed at several sites involved in the wind erosion project to determine the health of soil by defining management practices that are soil building rather than degrading. The objective of this research is to characterize biological, physical and chemical soil quality parameters and monitor their changes over time in minimum tillage and no-till seeding systems as affected by tillage, crop species and management systems. For several of the sites tested, as the time into no-till increases, we find increased organic carbon values, changes in the microbial community and decreases in bulk density in the surface soil. Other soil quality parameters are variable in their response. The change with soil quality parameters in the transition period to no-till appears to take longer and can be more variable in lower rainfall zones. Changes in cropping systems were difficult to measure; however, differences in soil quality parameters were often seen with changes in crop type or sequence. Changes occurring with microbial communities can be measured before changes in organic matter or other chemical or physical parameters. No single soil quality measurement was able to predict changes in some of the other parameters. From this research, information will be obtained to better assess the health or quality of soils specifically for the dryland-farming region of eastern Washington and north central Idaho. This information will ultimately provide growers and scientists with practical advice on soil quality to aid in the development of management practices.