Evaluation of Diverse Soybean Germplasm for Forage Yield and Quality.

In the summer of 2007 a forage soybean experiment was conducted at the University of Arkansas Agricultural Experiment Stations in Fayetteville, and Kibler, Arkansas. The main objective of this research was to determine how selected forage and grain soybean genotypes perform as forage crops in the Mid-South region of the United States. We hypothesize that forage soybean genotypes will have higher biomass yields than grain soybean genotypes; however forage quality is expected to be similar among both forage and grain genotypes. To test this hypothesis an experiment with 15 genotypes in a randomized complete block design with three replications was grown in four 6.1-meter row plots with 96.5 centimeter row spacing. Aerial biomass production, fiber content, and protein content were measured at soybean reproductive stages R1 and R6. Seed yields were measured at soybean reproductive stage R8. Biomass yields at reproductive stage R1 for the forage-type cultivars ranged from 4.7 to 5.8 Mg/ha as compared to 3.8 to 4.8 Mg/ha for the grain-type cultivars. Biomass yields at reproductive stage R6 for the forage-type cultivars ranged from 10.7 to 12.8 Mg/ha as compared to 10.5 to 12.7 Mg/ha for the grain-type cultivars. Seed yields of grain-type cultivars ranged from 2411 to 3665 kg/ha compared with 1290 to 2210 kg/ha for forage-type cultivars. Forage quality data will be reported later.