Corn that has been affected by drought can be used as a feed for cattle. Before harvesting the drought damaged corn field for something other than the grain, check with your crop insurance person to determine what needs to be considered to make sure that the field can be put up as a forage crop and still receive any insurance that is possible.
The drought damaged corn plant will likely contain nitrates. Data indicates that the nitrates reside in the bottom 6 to 8 inches of the stalk. Use management strategies to reduce any possible cattle losses due to high nitrates in feed.
A drought damaged corn field can be salvaged as corn silage. Harvesting the drought damaged corn field as silage will reduce nitrates by 30 to 60 percent. To reduce the nitrates through the ensiling process, allow the silage to go through the 21-day fermentation process before opening the bunker to feed. Ideal moisture content of the silage for packing into a bunker is 65% (35% dry matter), with a range of 62 to 68 percent moisture. This is critical when making silage. If the silage is to wet, there will be excessive seeping and spoilage and proper fermentation will not occur. If the silage is too dry, then it will be difficult to pack and make the anaerobic conditions necessary for the fermentation process.
It is difficult to determine when to chop a drought damaged corn field for silage. The chop material when it is green may be as high as 80% moisture, which is too wet to pack into a bunker. At this moisture content, let it continue to dry in the field. An extra step in making silage would be to windrow the field and let it wilt in the field until the desired moisture content is achieved for chopping and packing into the bunker.
To determine the moisture of the standing crop, select some stalks and cut them at the same height that the chopper will be set. Cut the stalks into small pieces (about ¾ to 1 inch in lenght) using a cleaver or heavy knife, mix the sample and then analyze the sample for dry matter using the microwave. Take a sample from some of the chopped material, weigh the sample then dry it down in a microwave. Reweigh the sample to determine the moisture. Microwave slowly so as not to "burn" the sample. Microwave and weigh until there is no change in weight of the sample after microwaving. This process requires a scale that can accurately weigh small amounts of material and changes in weight due to water. Most producers are not set up to test moisture using this method.