Effects of low-till parabolic subsoiling frequency and furrow irrigation frequency on maize in the Yazoo-Mississippi Delta

Abstract

Naturally forming or mechanically induced hardpans limit water infiltration and crop productivity in many agricultural regions including the Mid-South U.S. This research was conducted to determine whether low-till parabolic subsoiling and furrow irrigation interact to influence soil water dynamics and maize production in the Mid-South. The factorial effects of subsoiling frequency (no subsoiling, NS; subsoiling only before cotton, CS; subsoiling only before maize, MS; and subsoiling every year, ES) × irrigation frequency (no irrigation, NI; low-frequency irrigation, LI; and high-frequency irrigation, HI) on infiltration, grain yield, and profit over specified costs were investigated for the maize portion of a maize-cotton rotation experiment in a silty clay loam soil near Tribbett, Mississippi. Subsoiling before maize improved the infiltration of irrigation (p < 0.05) but not the infiltration of in-season rainfall for irrigated treatments. By subsoiling before maize, high-frequency irrigation maximized grain yield in just one—rather than three—out of five years. Subsoiling before maize also increased non-irrigated yield in all five years. Overall, the combination of subsoiling only before maize and low-frequency irrigation achieved the largest average profit and a relatively small risk. These findings support the practice of low-till parabolic subsoiling before maize as a hydrologically effective and economically viable strategy to conserve freshwater resources in the Mid-South.