Efficiency of residue management for providing optimal corn growing conditions in a non-tilled sandy loam
No-till corn production is a soil conserving system that presents several challenges in terms of crop performance. The presence of crop residues on the soil surface results in many changes of physical, chemical and biological nature. These changes concern mainly soil temperature but also, soil water content, nutrient availability and phytotoxicity. In order to distinguish between residue effects on corn due to low soil temperatures fromother residue effects, corn development was related to soil temperature for eight different types of residue covers: grain corn, spring canola, spring barley, spring barley and red clover killed early or killed late, soybean, soybean and fall rye killed early or killed late. Analysis shows that only corn plants growing in canola residues may have been delayed by a factor other than soil temperature. The changes in soil temperature result almost invariably in delaying development of a corn crop when residue-covered soil is compared to a bare soil. The objective of another study was to determine if clearing the residues off the row in the interrow could alleviate the problem and improve the water status of a droughty soil. This management study showed that half of the delay (5 days) due to the presence of residues on the no-till plots could be avoided by clearing the residues off the row. This practice did not have much effect on water content when the plants had attained a large size. Two hybrids previously rated well and less-well suited for no-till production in 1988 in Huron county were used in the study. The hybrid rated less-well suited for no-till production yielded more grain per plant than the other hybrid. These hybrids were also used in another study designed to address the problem of uneven plant emergence and final establishment in no-till corn production. This problem is due to changes in surface properties of no-till compared to conventional tillage. There was a need to measure the variability of emergence and try to correlate it to some selected soil properties. The soil properties studied were soil water content, bulk density and seed depth. Bulk density was negatively correlated to emergence in conventional plots and water content was negatively correlated to emergence in no-till plots. The emergence of the hybrid rated less well-suited for no-till production in 1988 was less variable and less sensitive to seed zone environmental conditions than that of the hybrid rated well-suited for no-till production.