Effects of Tillage, No Tillage, and Mulch on Soil Water and Plant Growth1

Abstract Seedbeds for corn (Zea mays L.) were prepared by both conventional tillage and the no‐tillage method, each with and without surface mulches. The mulches consisted of killed grass sod on the no‐tillage plots and straw applied on plots with conventional tillage. No‐tillage plots without a mulch were obtained by removing the killed sod. Mulched treatments, whether of undisturbed killed sod on the no‐tillage plots or of straw on conventional plots, gave the lowest values for runoff and the highest values for soil water content and yield of corn. Soil water conserved by the mulches was reflected in an average grain yield increase of 1,932 kg/ha. Differences in total soil water among treatments were significant to a depth of 30 cm. The effect of tillage was minor, but the data indicate the value of the killed sod mulch in the no‐tillage system.