Uniform Stand and Narrow Rows are Needed for Higher Double-crop Soybean Yield

Abstract

Double‐crop soybean producers do not always realize a yield benefit when they convert from a 15‐inch planter to a 7.5‐inch grain drill. Poor seed singulation with drills was suspected to limit narrow‐row yield response. Experiments were conducted to determine if a precision drill with 7.5‐inch row spacing and accurate soybean seed singulation would improve stand uniformity and/or increase yield over a standard grain drill with poor seed singulation or a vacuum‐meter planter with 15‐inch row spacing and accurate soybean seed singulation in a double‐cropped soybean system. The effects of planter speed on stand uniformity and yield were also investigated. Stand uniformity with the precision drill was equal to the vacuum‐meter planter and better than the standard drill. Soybean yield with the standard drill was equal to the vacuum‐meter planter in three of four years and less than the vacuum‐meter planter in one year. Soybean yields were greater when planted with the precision drill than when planted with the vacuum‐meter planter in 2 of 3 years, and averaged 10% over three years of study. Planting speeds of 5 or 7 mph did not affect stand uniformity or yield.

Evaluation of Wheat Planted on 15-Inch Row Spacing in Eastern Kansas

“…], many farmers may already have planters that can plant 15‐inch rows. Additionally, these planters have an advantage over most drills in their ability to precisely place seed in high‐residue environments and to accurately meter the seed (3). A grower may be able to tolerate a minor yield penalty because of wider rows after factoring in the reduced cost of equipment and improved seed placement and metering of a planter instead of purchasing a drill.…”

Winter Wheat Yield Response to Wide Rows Varies By Year in the Southern Ohio River Valley

“…If farmers could use the same planters for soybeans and wheat, they could improve equipment efficiency. Planters should provide better penetration of crop residue than drills, which should improve seed placement (9).…”

“…All seeding was conducted with a small‐plot drill. One of the perceived advantages of 15‐inch rows is the ability to use a planter, which may provide better seed placement and possibly more accurate seeding rates (9). That component was not evaluated in this study.…”