Effects of Furrow Diking and Tillage on Corn Grain Yield and Nitrogen Accumulation

Abstract

AbstractCultural practices that conserve soil and water while maintaining or improving crop yield and quality are needed. Furrow diking and reduced tillage may constitute two such practices. The effects of furrow diking in combination with reduced (ridge tillage) or conventional disk tillage on soil‐water content, grain yield, and N accumulation of corn (Zea mays L.) were evaluated on a Weswood silt loam/Ships clay intergrade (fine‐silty, mixed thermic Fluventic Ustochrept/ very‐fine mixed thermic Udic Chromustert) near College Station, TX in 1987 and 1988. Five N rates (0, 75, 150, 225, and 300 kg N ha−1) as NH4NO3 were preplant subsurface banded into plots representing all combinations of tillage (reduced or conventional) and diking (all furrows diked or all furrows open). Neither diking nor tillage significantly increased soil‐water content in the above average rainfall year of 1987. In contrast, furrow diking with conventional tillage, and reduced tillage, with or without diking, significantly increased soil‐water content in the surface 150 cm compared to nondiked, conventional tillage treatments in the below average rainfall year of 1988. Diking significantly decreased or tended to reduce grain yields in 1987 at most fertilizer‐N rates, but had no effect on grain yield in 1988. Diking significantly increased grain‐N accumulation at the 150 kg N ha−1 rate in 1987, but had no effect at higher or lower N rates. Leaf‐N concentration was not affected by diking in 1987, and diking had no significant effects on grain‐N uptake or leaf‐N concentration in 1988. Effects of N fertilization on grain yield, grain‐N accumulation, and leaf‐N concentration were generally similar for reduced and conventional tillage treatments.