Winter soil microclimate altered by corn residue management in the northern Corn Belt of the USA

Management of crop residue is important for promoting soil water recharge and early spring thaw in the northern Corn Belt of the USA. This study assessed the impact of residue management in no tillage, continuous corn (Zea mays L.) production systems on the soil thermal and water regime during winter in west central Minnesota. Residue treatments were initiated in the fall over three years and included the removal of stubble and loose residue (RR) from the soil surface, all residue lying prostrate (PR) on the soil surface, and stubble standing and loose residue lying (SR) on the soil surface. Soil (to 0.3 m depth) temperatures were recorded hourly whereas soil water content, frost depth, and snow cover were measured weekly. The SR treatment effectively trapped more snow, which resulted in warmer soil (2 degrees C or less), shallower frost penetration las 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 depth and duration of soil freezing were the same for the RR and PR treatments. Soil water content was the same for all treatments prior to fall freezing, but was less for the PR treatment than for the SR or RR treatment during 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. (C) 1998 Elsevier Science B.V. All rights reserved.