Three Tillage Systems Affect Selected Properties of a Tiled, Naturally Poorly‐Drained Soil1

Abstract

AbstractReduced tillage systems for corn (Zea mays L.) have seldom shown a yield advantage on naturally poorly drained soils. This research was intended to further test this hypothesis and to find other advantages of reduced tillage on tiled, naturally poorly drained soils. The effects of three systems of tillage on selected soil properties, and growth and yield of corn were compared for 7 years on a tiled, naturally poorly drained Chalmers silty clay loam (Typic Argiaquoll) soil. Conventional or plow tillage consisted of fall moldboard plowing to about 20 cm, two diskings in spring, planting, and one cultivation; field cultivation included field cultivation in spring to about 15 cm followed by two diskings, planting, and one cultivation, and “light disking” included one disking in spring and planting behind fluted coulters but no cultivation. After 7 years organic matter percentages under field cultivation (4.68%) and light disking (4.89%) systems were higher (p < 0.05) than that under plow (3.79%) tillage at the 0 to 5 cm depth. Mean weight diameters of water‐stable soil aggregates were higher (p < 0.05) for field cultivation (2.74 mm) and light disking (2.48 mm) systems than for the plow tillage (1.51 mm) system. In early October, after a summer of low rainfall, soil moisture was higher (p < 0.05) with field cultivation (35.9%) than with the plow tillage (32.3%) system. Even though tasselling was generally later (5 days in 1974) with the field cultivation and light disking systems than with the plow tillage system, annual (1968‐1974) corn grain yields were 97.1 and 98.9% respectively, of those obtained with plow tillage (8,700 kg/ha).