Effect of sulphur fertilization on nitrogen and sulphur uptake by alfalfa on chernozem and brown forest soil

absorption de substances nutritives agricultural chemicals agronomic characters analisis analyse analyse chimique analysis azufre chemical analysis chernozem chernozems composition contenido de materia seca crops cultivos dicotiledoneas dicotyledons dry matter content economic plants elements engrais environment environnement feed crops feed legumes fertilizantes nitrogenados fertilizers fisiologia fonction physiologique genetic soil types legumes leguminosae leguminosas leguminosas forrajeras medicago medicago sativa medio ambiente methode methods nitrogen fertilizers no metales nonmetals nutrient uptake papilionoideae physiological functions physiologie physiology plantas plantas forrajeras plante plante de culture plants productividad productivity produit agrochimique profitability rendement rendimiento rentabilidad rosales site factors soil types soufre sulphur type de sol yields