New UNL Manure Nitrogen Crediting Recommendations for Crop Fertility
University of Nebraska-Lincoln (UNL) has changed recommendations for crediting nitrogen following manure applications for field crops.
Previously, recommended availability factors varied by species, only credited feedlot manure organic-N availability as 25% for the first year. However, new research has shown that most manures are similar; and recommended organic-nitrogen availability factors have moved up to 40% in year 1; 20% in year 2; and 10% in year 3 following application for most animal manures (except for poultry layer and composted beef feedlot manures).
Research has also shown less nitrogen loss from the ammonium-N fraction in liquid manure when applied by pivot irrigation at two different rates. The new changes show that the availability factor of ammonium-N from sprinkler irrigation is 80% when applied at more than 0.4 inches and 40% when applied at or less than 0.4 inches.
To read more about the new recommendations and resulting impacts for field crop producers, read this UNL Water article.