Late-planted soybeans will be racing Jack Frost to the finish line in the northerly regions of the Northeast. With the need for high-quality dairy forages ratcheting higher along with the need to reduce purchased feed inputs, harvesting immature soybeans as a forage crop merits a look.
Nutritive value of baled soybeans can be comparable to early-bloom alfalfa, notes Alvaro Garcia, South Dakota State University Extension dairy specialist. But the crop needs to be baled when pods are almost full of seeds and lower leaves are just starting to turn yellow. At that maturity, pod digestibility contributes significantly to overall nutritive value of the whole plant.
Conditioning will speed dehydration of stems and leaves and bring total moisture below 25%. Rake no more than you must, as leaves and pods tend to shatter easily.
Soybean silage comes later
If you choose to chop beans, moisture recommendations are similar to that of alfalfa silage. Soybeans should be harvested right before pods are full. Waiting until complete maturity results in a forage of lower digestibility. It can also lead to fermentation problems due to the seeds' high oil content, cautions Garcia.
Mixing one-third corn silage with soybean silage avoids those problems. Corn boosts the soluble sugars to speed fermentation and dilute bean fat content, he adds.
Aim for ensiling 35 to 40% dry matter content. Inoculants may help minimize fermentation problems and hold down mold growth.
Also, Garcia adds, be aware of any herbicide restrictions before considering soybeans as a forage.