Farmers giving up on their drought-stressed corn and soybeans for grain may find value in chopping the plants for silage, especially in situations of low forage inventory.
Bill Weiss, an
“For both corn and soybeans, harvesting them at the correct dry matter level is the most critical aspect of silage-making,” said Weiss. “Corn and soybeans may be drought-stressed, but they still have a lot of water locked up in the plants. If they are not chopped at the correct dry matter level, the crops won’t ferment correctly and you’ll end up with poor-quality silage.”
Weiss said that corn should be chopped when the plant contains 30 percent to 38 percent dry matter. For soybeans, dry matter content should be in the range of 35 percent to 45 percent. Plants chopped with improper dry content matter can mold and spoil during storage and feed out.
Weiss recommends that producers cut corn plants and run a dry matter analysis of the crop before chopping it.
Other guidelines to prepare corn for silage include:
Avoid feeding freshly chopped green plants to livestock because of potential nitrate toxicity. “Silage fermentation can greatly reduce nitrate concentrations,” said Weiss. “If greenchopping must be done because of limited forage supplies, set the chopper high because nitrates accumulate in the lower stalk.”
Analyze drought-stressed corn for proper nutrient balance. “The nutrient composition of drought-stressed corn will be more variable than normal corn silage,” said Weiss. However, if fermented properly, drought-stressed corn is a high-energy, nutrient-packed forage that is suited for even high-producing dairy cows. Compared to standard corn silage, drought-stressed corn silage contains more protein and fiber, has less starch, and is slightly less digestible.
Guidelines to prepare soybeans for silage include:
Take note of the stage of the soybean crop when chopping for silage. Soybeans further along in development will contain higher levels of oil (fat content) in the seeds, inhibiting fermentation. “If soybeans contain more than 10 percent fat, they should be blended with other crops, such as corn, at the time of ensiling,” said Weiss.
Finely chop silage to encourage stem consumption.
Follow the same procedures to prepare soybeans for silage as one would for preparing alfalfa for hay. Weiss said that the nutrient value of soybean silage is similar to early to mid-bloom alfalfa.
Consult chemical suppliers regarding herbicide use on soybeans earmarked for silage. Certain herbicides may not be approved when harvesting the crop as silage.
For more information on managing livestock in times of drought, log on to http://beef.osu.edu/Drought07.html.