Assessing soil quality changes in alternative and conventional cropping systems

Assessing soil quality changes in alternative and conventional cropping systems

Summary

Objectives:
1) Characterize the effect of rotation and management systems on soil quality and biomass production in long-term experiments with previous high and low fertility management,
2) Valuate the same soil quality characteristics for similar soils using paired-field or paired-farm comparisons of long-term alternative production systems with those in conventional systems or those recently converted to alternative management,
3) Develop and implement an outreach component for dissemination of information concerning the impact of alternative management on soil quality.

Many farmers on highly productive Mollisols in southwestern Minnesota feel ‘locked-in’ to a 2-yr corn soybean rotation, and these two crops are currently planted on more than 90% of the cropped land in this region. However, long-term replicated studies at the Southwest Research and Outreach Center (SWROC) comparing rotation length and alternative and conventional management systems have shown a 4-yr rotation to be superior to the 2-yr corn-soybean rotation in terms of net economic returns. Although sampling and analysis of a limited number of soil parameters has been undertaken for some management systems and crops, there has been no comprehensive assessment of the long-term impacts of the various rotation and management systems on soil quality. The purpose of this project is to determine the how the rotations and management have affected a number of biological, chemical and physical properties of the soils in this long-term experiment, and to supplement these results with on-farm comparisons between fields under well-established (>10 years) alternative practices and those under conventional management or which have recently been subject to alternative management.

Collaborators: