Prediction of Nitrogen Fertilizer Requirements of Field Crops. II. Application of Theoretical Models to Malting Barley1

Abstract

AbstractFive indices of soil organic nitrogen availability and mineral plus fertilizer nitrogen were used in the prediction of grain yield, grain protein content, and grain protein nitrogen of Moravian barley. Three mathematical models were employed, one of which included only soil mineral plus fertilizer N for prediction of crop parameters. The remianing two models, which included both organic and mineral plus fertilizer N showed improved predictability of crop parameters. No organic nitrogen measure showed superiority to others, however, one equation model was advantageous in studying the relative contribution of soil organic N to crop production.