Craig Sheaffer, Extension Agronomist; John Lamb, Nutrient Management Extension Specialist (Emeritus) and Carl Rosen, Extension Soil Scientist
Corn stover remaining in the field following grain harvest is a valuable resource providing significant benefits to soil conservation and soil health. In addition, the nutrients in incorporated corn stover are recycled and used by the following crop. Harvest of corn stover for livestock feed or bedding reduces its beneficial effects on soil.
Soil conservation
Stover left on the soil surface or partially incorporated provides residue that can reduce soil erosion by wind and water. Incorporation of stover improves soil health by increasing soil carbon and tilth, water infiltration. Of course, the impacts of corn stover on these attributes is dependent on the amount of stover produced and left on the field. Because corn grain and stover yields are related (typically a 1:1 ratio), as grain yields increase so does stover production.
In our research over several locations in Minnesota, we found the corn stover production ranged from 3.2 to 4.0 tons/acre and on average 3.8 ton/acre. An average of 0.8 ton/acre of corn cobs were produced (Tables 1 and 2). However, because of differences in cropping systems, tillage, soil erosion potential, and harvest methods, farmers typically only harvest a part of the stover residue. Minnesota Extension provides a decision support tool for deciding the amount of corn residue to harvest for various crop rotations, tillage systems and yield levels.
Livestock feed and bedding
Corn stover is used as livestock feed and bedding. Corn stover is low in nutritive value. It contains about 5% crude protein, 70% NDF concentration, and 50% dry matter digestibility. It is often used in maintenance rations of non-lactating beef cows. Supplementation with energy and protein are required if corn stover is the primary ingredient in rations for growing and lactating animals.
Grazing is a cost-effective on-site approach to stover utilization and cattle can be more selective and eat the higher quality leaves and grain lost in combining. (Felix, 2023). Grazing livestock also deposits manure nutrients as they move over the field and through hoof traffic increases decay of stover. Baled corn stover is often lower in quality than grazed stover because of field harvesting losses which include chopping, shredding, and raking. Dried corn stover can be used as livestock bedding and will absorb 2.5 times its weight in water compared to 2.1 for wheat straw.
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Categories: Minnesota, Crops, Corn