Northeast Research and Demonstration Farm
Oat is the majorspring-sown small grain crop in Iowa. Spring-sown small grains can be used for grain and straw production, as a companion crop to establish hay and pastures, or for early-season forage as hay or haylage. Because small grains generally mature before the end of July, a forage legume, cover crop, or green manure crop can follow oats, or animal manure can be spread on the field in which oats were grown.
Iowa State University
Lang, Brian J. and Pecinovsky, Kenneth T., "Oat Variety Trial" (2013). Iowa State Research Farm Progress Reports. 1939.