Furrow and Flood Irrigation of Early‐Planted, Early‐Maturing Soybean Rotated with Rice

Abstract

The ESPS (Early Soybean Production System) is being adopted in the midsouthern USA to avoid some of the effects of normal late‐season drought. Field studies with soybean [Glycine max (L.) Merr.] grown following rice (Oryza sativa L.) were conducted in 1994, 1995, and 1996 at Stoneville, MS, on Sharkey clay (very‐fine, smectitic, thermic Chromic Epiaquert) to compare yield of Maturity Group (MG) IV and V cultivars grown under furrow vs. flood irrigation, and yield and economic performance of nonirrigated (NI) and furrow‐ and flood‐irrigated MG IV and V cultivars. Three‐year average yields from irrigated MG IV and V cultivars were significantly greater than average NI yield. Within each year, yields from MG V cultivars equaled or exceeded those from MG IV cultivars in all environments. Furrow‐irrigated MG IV cultivars yielded significantly more than NI cultivars in all 3 yr, while flood‐irrigated MG IV cultivars yielded more than NI cultivars in 2 of the 3 yr. Both furrow‐ and flood‐irrigated MG V cultivars yielded significantly more than NI cultivars in 2 of the 3 yr. Three‐year average net returns from furrow‐ and flood‐irrigated environments were similar, and both were greater than those from the NI. Within each year, average net return from MG V cultivars in all environments was equal to or greater than that from MG IV cultivars. These results indicate that the ESPS can be used to effectively grow soybean in a rice–soybean rotation on clay soil, and that irrigation will usually result in greater profit from soybean.