Long‐Term Effect of Five Tillage Systems on Corn Response and Soil Structure

Abstract

AbstractTillage systems need to be compared over an extended period of time to determine their transitional and long‐term impacts on crop growth and soil properties. A 15‐yr experiment established in 1976 compared reduced tillage systems with conventional fall moldboard plowing for production of continuous corn (Zea mays L.) on a Maryhill silt loam soil (Typic Hapludalf). Corn plant growth and yield and soil properties were compared for five tillage systems: fall plow (fall mold‐board plow + spring secondary tillage), fall chisel plow (fall chisel plow + spring secondary), spring plow, spring plow/secondary (spring plow + secondary), and no‐till. No‐till consistently resulted in slower plant growth than most or all of the other tillage systems. The fall plow and spring plow/secondary treatments resulted in grain yields averaging 5% more than fall chisel plow, 9% more than spring plow, and 16% more than no‐till yields. From 1976 to 1983, no‐till yields tended to increase relative to fall plow; from 1988 to 1990, however, no‐till yields were much less than fall plow. No‐till resulted in the lowest proportion of aggregates <5 mm in diameter, highest bulk density, and greatest penetrometer resistance. Penetrometer resistance of the spring plow plots increased at a slower rate with depth than the fall chisel plow system. Among soil properties measured, the proportion of aggregates <5 mm in diameter was most often significantly correlated with yield.