Submitted to: Proceedings from Dynamic Cropping Systems: Prinicples, Processes, and Challenges
Publication Type: Proceedings
Publication Acceptance Date: July 1, 2003
Publication Date: August 1, 2003
Citation: WIENHOLD, B.J., PIKUL JR, J.L., LIEBIG, M.A., VIGIL, M.F., VARVEL, G.E., DORAN, J.W. CROPPING SYSTEM EFFECTS ON SOIL QUALITY IN THE GREAT PLAINS: SUMMARY FROM A REGIONAL PROJECT. Proceedings from Dynamic Cropping Systems: Prinicples, Processes, and Challenges. PP 215-219. 2003. Interpretive Summary: Soils are important to agronomic production and environmental quality. To evaluate how management is affecting soils, key properties are often compared among management alternatives or over time. A better understanding of how key soil properties vary over the growing season and the sensitivity of those properties to changes in management is needed. A number of long-term cropping systems experiments exist in the Great Plains. This study utilized those long-term systems to determine how a number of soil properties changed with time and differed among contrasting management practices. These comparisons were facilitated using an indexing tool that integrates soil property values into an index that can be compared across time and among management practices. Results showed that soil properties differed among management practices in drier areas of the Great Plains, mainly due to the incidence of fallow. In areas receiving more precipitation, management differences were not apparent but a number of soil properties varied with time because of year-to-year variations in precipitation and crop production
Technical Abstract: Soils perform a number of essential functions that are often assessed by measuring physical, chemical, and biological properties related to soil functions affecting the management goal. Information is needed on the temporal dynamics of commonly measured soil properties, the sensitivity of these properties to management, and the utility of new methods in soil quality assessments. In 1998, a regional project was initiated to utilize existing long-term cropping system studies at eight locations in the Great Plains to provide this information. The Soil Management Assessment Framework was used to calculate an index for soil properties repeatedly measured under contrasting management practices from 1999 to 2000. Index values were used to detect temporal changes in soil properties and management affects on soil properties. Results indicate soils from semi-arid locations developed under mixed or short grass prairie (Swift Current, SK, Mandan, ND, Akron, CO, and Bushland, TX) are more sensitive to management than soils receiving higher amounts of precipitation and developed under tall grass prairie (Fargo, ND, Brookings, CO, and Mead, NE). Temporal changes were related to weather and crop production differences among years. Differences between management practices were related to the incidence of fallow.