Utah State University Extension
Nitrogen (N) fertilizer is one of the most expensive crop inputs. It is an essential nutrient for most crops and often increases yield more than any other nutrient. Small grains are no exception. Alfalfa is the dominant crop in Utah in terms of area and gross sales, and as a nitrogen-fixing legume, it does not require nitrogen fertilizer. When terminated, alfalfa usually leaves a lot of nitrogen in the soil for subsequent crops. The amount of nitrogen that it supplies to following crops has been termed the “alfalfa N credit.” In many cases, this credit can be up to 300 lbs. N/acre for the two crops following alfalfa. This fact sheet addresses the nitrogen fertilizer needs of small grains grown for forage and for grain and corresponding economics.
Yost, Matt; Pound, Collin; Creech, Earl; Cardon, Grant; Gale, Jody; Pace, Michael; Kitchen, Boyd; Price, Steve; Heaton, Kevin; Nelson, Mark; Wilde, Trent; and Russell, Katie, "Nitrogen Fertilizer Guide for First-Year Small Grains Following Alfalfa" (2020). All Current Publications. Paper 2120.