How to Use Drought-Stressed Soybeans for Forage

By Blake Jackson

Pennsylvania and surrounding regions are currently experiencing severe late-season drought, which can significantly impact grain soybean crops. Drought-stressed soybeans may produce fewer pods and smaller seeds, leading to reduced grain yields.

Similarly, forage production and inventories may be lower than usual. Under these conditions, harvesting drought-affected grain soybeans for forage can be a practical solution.

Soybean forage is high in crude protein (18-20%), relatively low in fiber (35-45%), and yields 2-4 tons of dry matter per acre. While its palatability is lower than many common forages, mixing it with other forages can improve acceptance.

Before chopping soybeans for forage, several factors must be considered. Pesticide restrictions are crucial; many herbicides, such as Liberty, Enlist One, Reflex/Flexstar, Dual, Canopy, Pursuit, Sonic, and Warrant, prohibit harvesting soybeans for forage.

Other products, including Roundup PowerMax3, FirstRate, and metribuzin, allow cutting only after a pre-harvest interval (PHI) ranging from 14-65 days.

Fungicides and insecticides may also have limitations. Always consult the current product labels before proceeding.

Crop insurance is another consideration. Farmers should contact their insurance agents to understand how harvesting for forage may affect coverage. Similarly, consulting with the USDA Farm Service Agency is recommended to confirm that USDA program eligibility will not be compromised.

When ready to harvest, timing is key. The ideal stage is just before R7 maturity, when at least one pod on the main stem has reached its mature tan or brown color.

At this stage, seed development largely ceases, dry matter peaks, seeds are about 60% moisture, and leaves begin yellowing. For drought-stressed crops, harvesting before leaf drop helps preserve forage quality.

Harvesting method matters as well. Silage or baleage is preferred over dry hay, as dry hay may be dusty, brittle, and prone to mold. Field wilting is recommended prior to ensiling, with silage moisture at 65-70% and baleage at 40-60%. Proper conditioning during mowing is important to retain leaves.

For feeding, mixing soybean forage with grasses improves palatability and reduces the risk of digestive issues due to high oil content.

Photo Credit: istock-urpspoteko