Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 13, 2001
Publication Date: N/A
Interpretive Summary: Cold and wet soils prior to planting in the spring commonly delay the establishment of crops in cold regions. Methods of managing crop residues following harvest in the autumn are sought that will increase soil temperatures and hasten drying of soils in the spring. Corn stalks cut farther above the soil surface at harvest provided the most ideal soil microclimate during winter. Taller stubble trapped more snow and thereby decreased frost penetration and hastened thaw in the spring. Cutting corn stalks at the soil surface or removing corn residue from the soil surface in autumn resulted in a more adverse microclimate during winter. Thus, corn producers who retain tall stalks on their fields during winter will likely be able to plant earlier in the spring as well as minimize soil degradation caused by snowmelt erosion.
Technical Abstract: Management of crop residue is important for sustaining biological activity in soils during winter and for promoting soil water recharge and early spring thaw in cold regions. This study assessed the impact of stubble height and residue placement in a corn production system on the soil microclimate during winter in the northern Corn Belt. Residue treatments were established in the autumn of 1993 through 1995 near Morris, Minnesota Treatments included 1) 60-cm stubble, 2) 30-cm stubble, 3) 30-cm stubble with alternating bare and residue covered interrows, 4) 0-cm stubble, and 5) 0-cm stubble with all residue removed from the soil surface. Snow cover, depth of soil freezing, soil temperature, soil water content, and reflected global and net radiation were monitored from November through March each winter. Taller (60 cm) stubble trapped more snow, reduced the depth of frost penetration by at least 0.5 m, moderated soil temperatures by at least 2 deg C during winter , and hastened thawing of the soil profile in the spring by at least 25 d as compared with short (0 cm) stubble (with and without residue). About 52, 93, and 40% of the variability in soil water recharge caused by residue treatments during successive winters could be explained by differences in snow cover, soil water content at commencement of soil freezing, and thaw depth among treatments. On clear days, albedo was highest for the 0-cm stubble and lowest for the 0-cm stubble without residue treatments. Net radiation, however, was lowest for the 0-cm stubble and highest for the 0-cm stubble without residue treatments. This study suggests that soils warm and thaw earlier in spring by retaining tall stubble on the soil surface after corn harvest in the northern Corn Belt.