|Harvesting corn stalks helped feed livestock last fall when other options were expensive or severely limited, but would leave fallowed fields with little cover this summer. A spring planting of oats may help provide some protection until the fallowed land is planted into wheat this fall. (Photos by Robert Klein)|
February 20, 2013
Protecting Barren Fields During Summer Fallow
Q: When livestock feed was short last fall, we harvested virtually all the corn residue from a field and are now leaving it fallow until seeding to winter wheat in fall 2013. What is the best way to fallow this to reduce the potential for erosion and capture as much precipitation as possible?
A: The best option last fall would have been to leave the crop residue or at least leave strips of residue to trap snow and reduce wind and water soil erosion. Many producers were faced with high feed costs and elected to cut silage or hay the failed corn crop.
Fallowing without crop residue leaves the soil subject to wind and water soil erosion. Plant residue mulches on the soil surface increase soil moisture by increasing water infiltration and reducing evaporation. Research conducted by Oscar Barnes and Dale Bohmont of the University of Wyoming Ag Experiment Station found that water intake at the end of one hour was 0.3 inches for bare fallow, 1.20 inches for grassland, and 2.26 inches for stubble-mulch.
Similarly, research by T.M. McCalla emphasized the importance of mulches on soil structure and showed that a surface mulch is more important than soil organic matter in increasing water infiltration. A subsoil devoid of organic matter and not mulched had an intake rate of 0.44 inches per hour, while the mulched subsoil infiltration rate was 0.76 inches per hour for the same period.
One option for these fields would be to seed oats as soon as soil conditions permit and use it as a cover crop. A suggested seeding rate for cover crop use would be one bushel per acre. (Make sure the oats do not contain any weed seed.)
Check with both the Farm Service Agency and your crop insurance representative to clarify that they will not consider this continuous cropping, and to determine the date the oats need to be destroyed. In most situations the oats will need to be destroyed before heading or by June 1, whichever occurrs first. You will want to destroy the oat planting after it has provided the protection needed for the soil and before it uses a large amount of water as the purpose of fallow is to accumulate soil water for the next crop.
Extension Western Nebraska Crops Specialist