Making Silage from Drought Damaged Corn
Drought has damaged corn in many areas. Growers should examine fields for grain potential.
Corn fields and even some irrigated fields have suffered severe drought or heat damage. Silage can salvage this crop, but some harvest modifications may be needed.
Most of the green, low grain corn is too wet right now to make good silage directly. In fact, even plants with brown bottom leaves may be too wet because stalks hold so much moisture. Usually, 65 to 70 percent moisture is ideal for bunker-type silos, but green stalks and leaves of corn can contain over 80 percent water.
Direct chopping and ensiling this wet corn can cause heavy seepage and a sour silage. The easiest way to lower moisture content is to wait until plants dry more naturally.
This may not happen until later and then it might quickly get too dry. If you can't wait, you can windrow corn and allow it to field wilt a few hours before chopping.
Taking the time to check the moisture content before harvesting could save a lot of trouble later. MU publication G3151 contains detailed information on how to measure the moisture content of silage using a microwave oven.
Drought-damaged corn should be chopped to 3/8 to 1/2 inch in length. This length of chop should help in packing the silage to exclude as much oxygen as possible. Producers should also sharpen the knives on their equipment before making silage.
High nitrate levels are frequently found where high levels of nitrogen fertilizer were applied and where drought-damaged corn is chopped a few days after a rain. Be sure to raise cutter bar to leave 10 to 12 inches of stalk in the field. Nitrates tend to accumulate in the lower portion of the stalks of drought stressed corn.
For more information, contact Wayne Flanary, Regional Agronomist, University of Missouri Extension at 660-446-3724.