Soybean Response to Zone Tillage, Twin‐Row Planting, and Row Spacing

Abstract

Although zone tillage can result in favorable in‐row seedbed environments for high crop yield while providing soil conservation characteristics similar to no‐till, it necessitates a wide row width planting system. The objective of this study was to evaluate various zone‐till systems for soybean [Glycine max (L.) Merr.] production. This study was conducted in southwestern Ontario from 1998 to 2000 on nine fields with clay contents between 133 and 354 g kg−1 and a minimum 5‐yr continuous no‐till history. Tillage systems evaluated were fall moldboard, fall zone‐till 15‐ and 30‐cm deep, spring coulter tillage, and no‐till. The no‐till and moldboard systems were planted in equally spaced 19‐, 38‐, 57‐, and 76‐cm rows plus a twin‐row configuration consisting of two 19‐cm rows centered 76 cm apart. Only single 76‐cm and twin‐row configurations were planted in the zone‐till and coulter‐till systems, where tillage was conducted in strips centered 76 cm apart. Twin‐row configurations in no‐till, spring coulter‐till, and fall zone‐till systems often increased yields over those obtained with single 76‐cm rows, with yields that were always similar to those obtained with no‐till planted in 38‐ or 19‐cm rows. Depth of fall zone tillage did not affect soybean yield. Fall zone‐till yields never exceeded those obtained with no‐till, even in environments where no‐till yields were less than those obtained with fall moldboard systems. Spring coulter tillage did not increase yields over those obtained with no‐till. Future research evaluating zone‐till systems for soybean should consider using twin‐row planting configurations.