Estimation of potentially mineralizable soil nitrogen from chemical and taxonomic criteria

Abstract

Abstract Estimates of mineralization of soil organic N are often needed to predict N fertilizer requirements of crops. G. Stanford and his collaborators developed laboratory techniques to estimate potentially mineralizable N (NO) in soils and a rate constant for mineralization (k). Their techniques have been used to estimate N mineralization in the field. This study reports the use of stepwise multiple regression techniques to estimate N from soil pH, organic carbon concentration, total N concentration, and soil taxonomy. The regression equation for No accounted for 83% of the variation of No for 90 samples from 67 soils representing eight soil orders. The regression equation for k accounted for 40% of the variation in the rate constant k for 61 samples from 43 soils. These results should aid in the estimation of N mineralization in cases where laboratory measurements of N and k are not available.