Comparisons of Single‐Row and Twin‐Row Soybean Production in the Mid‐South

A Maturity Group (MG) IV and MG V soybean [ Glycine max (L.) Merr.] cultivar were planted on beds in 102 cm single‐rows or 25 cm twin‐rows with 102 cm centers at 20, 30, 40, and 50 seeds m −2 in a Beulah fine sandy loam (coarse‐loamy, mixed, active, thermic Typic Dysrudepts) in 2008, 2009, and 2010 and in Sharkey clay (very‐fine, smectitic, thermic Chromic Epiaquerts) in 2009 and 2010 at Stoneville, MS. Despite furrow irrigation, drought and consistent maximum temperatures −32°C during 2010 reduced stands, yields, and seed weight at both sites. Twin‐rows produced more plants than similar single‐rows, which helped increase twin‐rows yields compared to single‐rows on the clay. Yields on the clay did not differ among seeding rates. Yields from twin‐rows on the sandy loam were only greater than single‐rows at 40 and 50 seeds m −2 for the MG IV cultivar and did not differ for the MG V. The MG IV cultivar tended to yield better than the MG V at both sites. The MG IV cultivar averaged 20 nodes plant −1 compared to 15 for the MG V. Both cultivars on the sandy loam average 59 pods plant −1 , while the MG V cultivar produced 70 pods plant −1 vs. 63 pods plant −1 for the MG IV cultivar on the clay. Twin‐rows did not produce more pods plant −1 Row type or seeding rate did not effect seed weight at either site. Seeds m −2 were greater for the MG IV cultivar on the sandy loam and corresponded with yield, but not so on the clay.