Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 12, 2001
Publication Date: N/A
Interpretive Summary: Cold and wet soils are often the most limiting factor in crop production and diversification in cold regions. Methods of managing crop residue following harvest in the autumn are to bolster soil temperatures and hasten drying of soils in the spring. Soils with no corn stubble and residue on the soil surface or with stalks cut farther above the soil surface at harvest provided the most ideal soil microclimate for the germination and development of crops in the early spring. These soils absorbed more solar radiation and thereby warmed faster in the spring. Since the winter microclimate is most severe for soils with no stubble and residue, growers may achieve the most ideal microclimate for microbial activity and plant growth during winter and spring by cutting corn stalks far above the soil surface and then removing loose residue from the soil surface.
Technical Abstract: Crop residue management systems are needed in the northern U.S. Corn Belt that hasten sowing and early establishment of crops in the spring. This study investigated the effect of corn stubble height and residue placement on the soil microclimate and associated development of wheat in the early spring. Treatments were established after corn harvest in the autumn of 1993-1995 and included 60 cm stubble, 30 cm stubble, 30 cm stubble with adjacent interrows devoid of and covered with prostrate residue (30 cm stubble with banded residue), 0 cm stubble, and 0 cm stubble without prostrate residue. Wheat was sown by hand and development of plants was assessed weekly from planting (mid-April) to late May. Net and reflected global radiation, soil temperature, and soil water content were measured in each treatment. Vegetative development of wheat was hastened by several days in soils with little residue cover (0 cm stubble without residue treatment and the bare interrow of the 30 cm with banded residue treatment because soil temperatures were at least 1 deg C higher throughout spring than those of the residue interrow of the 30 cm stubble with banded residue treatment. The 0 cm stubble without residue treatment was warmer due to a lower albedo (at least 0.03) and higher net radiation (at least 0.5 MJ m**- 2 d**-1) compared with all other treatments. Little difference in soil water content was found among the treatments, although treatments with little residue cover were wetter in two of the three springs. This study suggests that soils with little residue cover or that have taller stubble on the surface will absorb more radiation and thereby enhance soil warming and early development of plants in the northern U.S. Corn Belt.