Anions - cations balance in the tobacco plant. Particular significance of the difference delta between alkalinity of total ash (ATA) and total nitrogen content (N)

aging alcalinidad alkalinity anion aniones anions cation cationes cations contenido mineral envejecimiento feuille hojas leaves mineral content nicotiana tabacum nitrogen content plantas estimulantes plante stimulante racine roots stimulant crops teneur en azote vieillissement