|Karlen, Douglas - Doug|
Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2010
Publication Date: 6/15/2010
Citation: Imaz, M.J., Virto, I., Bescansa, P., Enrique, A., Fernandez-Ugalde, O., Karlen, D.L. 2010. Tillage and Residue Management Effects on Semi-Arid Mediterranean Soil Quality. Soil & Tillage Research. 107:17–25. Interpretive Summary: Globally, many producers are reluctant to use no-tillage because they believe those practices will increase soil compaction and decrease the volume of soil available to plant roots for water and nutrients. One way to demonstrate that this is not what will happen is to measure and evaluate many soil quality indicators. This project was conducted to evaluate several soil quality indicators that would encourage producers to use no-tillage practices. The results showed that use of no-tillage practices in this semi-arid, Mediterranean region of Spain had positive effects on soil quality. These results will be useful for soil scientists studying soil resouce management and especially for conservationists and land managers who help producers make decisions regarding best management practices for their soil resources.
Technical Abstract: No-tillage practices for semi-arid Mediterranean soils can conserve water and increase crop productivity, but producers are reluctant to adopt those practices because of concern regarding potential increases in penetration resistance and bulk density. We hypothesized that knowing more about all aspects of soil quality could encourage adoption of no-tillage, but methods for selecting indicators and assessing soil quality have not been developed for this region. Our objectives were (1) to identify the most sensitive soil quality indicators for evaluating long-term tillage and residue management within a semi-arid Mediterranean environment using factor analysis and (2) to compare soil quality assessments using those indicators with traditional methods of evaluating soil management such as changes in water retention, earthworm activity and the organic matter stratification ratio. Several soil physical, chemical, and biological measurements were made on four treatments (conventional tillage, minimum tillage, and no-tillage with and without stubble burning) included in a long-term (10-year) study in NE Spain. Sampling depth and management (tillage and crop residue treatments) significantly affected the physical, chemical and biological properties evaluated individually and collectively in this study. Principle component analyses identified three factors that accounted for 75 and 85% of the variation in soil measurements for 0 to 5- and 5 to 15-cm depth increments. Multivariate and factor analysis proved to be useful for selection of appropriate SQI for Mediterranean semi-arid rainfed cereal cropland. We conclude that showed that the implementation of NT techniques on Mediterranean semi-arid land had positive effects on soil quality.