Large parts of the southwestern Prairies are experiencing drought this summer and hail has struck many areas in the past few weeks.
Crops and forages may be severely damaged, but there are alternative uses.
Drought-stressed crops can be salvaged as livestock feed, but testing for nutritional value and harmful substances is extremely important.
Nitrate toxicity and aflatoxins may be a problem when plants are stressed by drought, hail or frost.
Stressed plants continue to take up nitrogen in the form of nitrates, but due to impaired photosynthesis, the nitrate is not converted to protein and it accumulates in stems and leaves.
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Nitrate accumulation is highest about three days after a hailstorm or frost. Hail or frost-damaged crops should be cut right away to prevent nitrate accumulation.
Another option is to cut the crops seven to 10 days after a stress event.
This allows accumulated nitrates to be converted to plant protein if the plants recover, or to be leached out if they die.
High-nitrate feeds should be fed in combination with low-nitrate feeds in order to reduce the total nitrate level in the diet to below 0.5 percent.
If animals are abruptly switched from a low nitrate level to a higher level, a build up of nitrates can be expected before the microbes in the digestive system adapt.
Feeding rations in two or three meals per day rather than one will reduce the amount of nitrate released from the feed at one time.
Forages
If forage plants show signs of drought stress, be careful about using them as fresh forage because nitrate levels may be high.
A better option is to use plants as silage, because the silage fermentation process reduces nitrate levels. In either case, testing is critical as nitrate poisoning can be a problem in drought- stressed crops.
Grain
Test drought-stressed oats and barley for nutritional value.
In severe cases, these crops can be reduced to empty hulls or a very light grain. The result is low energy and protein and limited feed value for poultry and swine.
Oats and barley may work well in combination with other livestock feeds. You may also want to consider silaging grain when there is little hay for winter feed.
Plowing it under
If the crop has no feed value or using it as livestock feed is not viable, it may be worth plowing the crop down for organic matter.
Producers should also consider the value of letting the crop stand for the winter to catch snow and reduce soil erosion. The following year, the crop can be plowed down during spring tillage.
Green manure may be a possibility as well, although most drought-stricken crops will be past the point of ‘green.’ However, some valuable nutrients may persist.
