A Comparison of Early and Recommended Soybean Production Systems in Tennessee

Abstract

The Early Soybean Production System (ESPS) is based on a favorable relationship between local weather conditions and the planting, growth, and development of soybean [Glycine max (L.) Merr.] plants. Most researchers in the southern region (Kentucky, Arkansas, Mississippi, Texas, and Florida) have found ESPS to be equal or superior to recommended production systems. However, several studies in Kentucky have shown decreased yields in ESPS. Also, poorer seed quality has been associated with ESPS. The first objective was to compare seed yield and quality of soybeans planted in ESPS and the recommended system. The second objective was to study the phenological aspects of the ESPS and recommended system using crop development and weather data. The recommended system in this study was MG IV and V (two cultivars each) with four planting dates from 29 April to 10 June and the ESPS was defined as MG III (two cultivars) with three planting dates 18 March to 15 April. The study was conducted at Springfield, Spring Hill, and Milan, TN, from 1992 to 1994. Results indicate that ESPS led to lower yields than the recommended system for Tennessee, even in the hottest and driest environment that occurred during the study. In general, ESPS soybeans were exposed to cooler and moister conditions than the recommended system, but the more favorable conditions did not result in increased yields. There was no difference in oil content between ESPS and the recommended system. The percentage protein was higher in ESPS, but the seed score was higher (poorer). Based on this study, ESPS does not appear to hold much potential as an alternative production system in Tennessee.