Planting Corn in Sod and Small Grain Residues with Minimum Tillage 1

Abstract High costs of labor, fuel, and machinery; need to conserve moisture; loss of soil from erosion; and desire to double crop are some of the factors considered in the trend towards no‐tillage methods of planting crops. No‐tillage planting of corn in Pensacola bahiagrass ( Paspalum notatum Flugge) sod and small grains such as rye ( Secale cereale L.) was compared to conventional planting “rotavating, disking, and planting” for 3 years on Lakeland fine sand (Typic Quartzipsamment). When Pensacola bahiagrass was treated with paraquat + residual herbicide before planting corn by the notillage method, it recovered quickly and competed with the corn for water and nutrients. Corn ( Zea mays L.) planted no‐tillage had lower yields than when conventionally planted, but after corn harvest the bahiagrass growth was adequate for grazing. Adding extra N to the no‐tillage corn increased yields of both corn and grass. Corn under no‐tillage in rye treated with paraquat + residual herbicides generally yielded about the same as conventionally planted corn. Pensacola bahiagrass when treated with glyphosate in combination with other herbicide was almost all killed and offered little competition to the corn. Forage yield in the fall was only 37% of yield after paraquat‐residual herbicide application. The effectiveness in controlling broadleaf weeds with atrazine, cyanazine, alachor, linuron, and combinations of these herbicides varied seasonally, but had no significant effect on corn yields. Weed growth at corn harvest was considerably less on the no‐tillage plots; however, after 3 years of continuous no‐tillage corn perennial weeds were beginning to appear while few perennial weeds were observed in the conventionally planted corn.