Evaluation of Forage Yield and Quality in Wild Soybeans (Glycine soja Sieb. and Zucc.)

Wild soybeans (Glycine soja Sieb. & Zucc.) are generally higher in protein and lower in oil with potential advantages as forage than cultivated soybeans. This study was conducted to evaluate forage yield and quality of wild soybeans. Three wild soybeans were compared to three cultivated soybeans for forage yield and quality at the full bloom stage, full pod stage, and full seed stage (R6) of development. The wild soybeans had significantly lower forage yield than cultivated soybeans at R6 which was determined to be the best stage to harvest based on forage quantity and quality. Wild soybean also had lower crude fat (2.0%) and crude protein (17.7%) concentration than cultivated soybean (5.7 and 21.3%, respectively) at the R6 stage. There were no significant differences for neutral detergent fiber, acid detergent fiber and relative feed value among growth stages between cultivated and wild soybean. The neutral detergent fiber was 40.2 and 40.4%, acid detergent fiber was 26.1% and 27.5%, and relative feed value was 161 and 158 at R6 stage for cultivated and wild soybean, respectively. Wild soybean had less forage yield at harvest time but had similar forage quality comparable to cultivated soybean. However, wild soybeans have smaller and softer stems for potentially improved palatability and feed intake than cultivated soybeans. Therefore, it will be a good genetic source to improve forage characteristics of soybean.