Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/1998
Publication Date: N/A
Interpretive Summary: Residue management options need to be explored that enhance soil warming in the northern Corn Belt where cold soils limit adaptation and productivity of crops. Our objective was to determine whether removing all crop residue, chopping residue, or allowing the residue to stand after harvesting corn with a picker-sheller would result in warmer soils and an earlier spring thaw. Our research showed that soils with residue standing on the surface during winter thawed by as much as 20 days earlier. Farmers who leave residue standing on the soil surface after harvesting corn may be able to plant earlier in the spring, thus potentially increasing the length of the growing season, and therefore potentially increasing corn yield.
Technical Abstract: Frequency and depth of soil freezing, which influence the physical state of soils in cold regions, can be altered by management of crop residues on the soil surface. This study assessed the winter thermal and water characteristics of a Barnes loam subject to no tillage and various residue treatments after corn harvest in west central Minnesota. Residue treatments were initiated in the fall over three years and included removal of all stubble and loose residue (RR), all residue lying prostrate on the soil surface (PR), and stubble standing and loose residue lying on the soil surface (SR). Soil temperatures, soil water content, frost depth, and snow cover where measured weekly. The SR treatment effectively trapped more snow which resulted in warmer soil (2 deg C or less), shallower frost penetration (as much as 0.5 m), and earlier soil thaw (up to 20 d) as compared with the RR or PR treatments. Winter soil temperatures and soil freezing depth and duration were the same for the RR and PR treatments. Soil water content was less for the PR treatment than for the SR or RR treatment during the winter, due to less snowmelt infiltration for the PR treatment. Corn production utilizing no tillage in the northern USA necessitates the retention of stubble on the soil surface for promoting warmer soil during the winter as well as earlier spring thaw as compared with removing or chopping stubble.