Estimating Corn Growth, Yield, and Grain Moisture from Air Growing Degree Days and Residue Cover¹

Abstract

Low spring soil temperatures commonly restrict the early growth of corn (Zea mays L.) in the northern Corn Belt. A quantitative assessment of the effects of tillage and residue management practices on soil temperature would improve tillage recommendations in this region. The effect of tillage and surface residue cover on seedbed soil temperatures and subsequent corn growth were studied at four sites in the northern Corn Belt that differed widely in soil characteristics including drainage, texture, slope, and organic matter content. Tillage systems included no‐tillage, chisel plow, moldboard plow, paraplow, ridge plant, and wheeltrack plant. A wide range of surface residue cover was imposed on each system at three sites. Corn emergence and leaf number to the six‐leaf stage were closely related to percent in‐row cover and air temperature growing degree days (air GDD) through their mutual relationship to soil temperature growing degree days (soil GDD) at all sites. For a given site and year, percent in‐row cover following planting was the major factor affecting corn growth rate until the six‐leaf stage. Corn planted under high percent residue cover required more time and consequently more air GDD to reach the six‐leaf stage. This added time represents a growth delay that can be expressed as the additional air GDD required to reach the six‐leaf stage. Such delays were related to increased grain moisture and decreased corn grain yield when net cumulative air GDD were less than the threshold value of 1319 and water stress was minimal. In‐row residue cover due to tillage and previous crop can have a major impact on the growth and development of corn in the northern Corn Belt. These factors should be considered in selecting tillage systems in this region.

Time Interval Between Cover Crop Termination and Planting Influences Corn Seedling Disease, Plant Growth, and Yield

“…Greater growth of the rye cover crop at shorter termination-time intervals also leads to greater surface residue cover, which lowers soil temperatures and increases soil moisture (Dam et al 2005;Swan et al 1987). Lower soil temperatures directly slow corn germination, growth, and development (Kaspar et al 1990;Swan et al 1987Swan et al , 1996.…”

“…Lower soil temperatures directly slow corn germination, growth, and development (Kaspar et al 1990;Swan et al 1987Swan et al , 1996. In northern corn-growing areas, soil temperatures of residue-covered soils are usually well below optimum early in the growing season (Kaspar et al 1990;Swan et al 1987Swan et al , 1996.…”

High Residue Conservation Tillage System for Cotton Production: A Farmer’s Perspective

“…In some cases (especially cold humid climates), yield reductions observed in no-tillage system have been attributed to cooler soil temperatures (from residue cover) that reduce seed germination and seedling growth (Swan et al, 1987;Bradford & Peterson, 2000). The Ingram's believe that, in addition to providing a guide for controlled traffic, the 14 inch skip in the cover crop planting (centered on the cotton row) alleviates this potential problem.…”

Effect of Implement on Soil Co2 Efflux: Fall vs. Spring Tillage

“…Toward the end of the study (April−May), there were a few cases (127,142,152,167 DAFT) where the undisturbed soil temperature exhibited trends that were lower than in the other tilled treatments, but differences were small (data not shown). It has been reported that soils in no−tillage systems exhibit cooler temperatures (vs. tilled soils), which can create seed germina tion and early stand development problems (Swan et al, 1987;Bradford and Peterson, 2000). However, it is important to note that in our study, "undisturbed" denotes lack of tillage during one overwintering period, rather than a long−term history of no−tillage.…”