Optimum N-fertilization of cereals as compared with current farming practice

abonos nitrogenados absorption de substances nutritives application rates avena crop yield crude protein cultivos de primavera culture de printemps dose d'application fertilidad del suelo grain granos hordeum nitrogen content nitrogen fertilizers noruega norway nutrient uptake precipitation proteina bruta rendement des cultures rendimiento de cultivos soil fertility spring crops temperatura temperature teneur en azote triticum