The nutrition conditions and fertilizer application design of 3 main apple varieties in Hebei Province

abonos analyse de tissus analyse statistique application rates besoin nutritionnel crop yield dose d'application engrais fertilidad del suelo fertilizers feuille hojas huerto frutal leaves malus pumila necesidades de nutrientes nutrientes nutrients nutritional requirements orchards rendement des cultures rendimiento de cultivos soil fertility statistical analysis substance nutritive tissue analysis verger