Tillage Implement Effects on Corn and Soybean Residue

Abstract

ABSTRACT Aphotographic method was used to measure the portion of soil surface covered by corn and soybean residue before and after passage of a tillage tool on seven long-term (previously established) tillage experiments in Iowa over a five-year period. Tillage implements vary widely in their effect on residue cover, ranging from burying over 80% of surface residue (chisel, soybean residue) to increasing residue cover (uncovering previously buried residues) by nearly 60% (planter, soybean residue). The effect of individual tools on corn and soybean residue cover is quite different, with the soybean residue cover showing a greater reduction from use of any given tool. Tillage in previously disturbed residue results in a smaller reduction in residue cover than when the residue has not been disturbed prior to tillage. Residue cover after a series of tillage operations can be estimated using the data presented. More operations can be performed on fields covered by corn residue than on fields covered by soybean residue and still maintain a given level of residue cover.