
Keywords: N; nitrogen; P; phosphorus; K+; Â potassium; Ca2Â +; Â calcium; CECeff; effective cation exchange capacity; Mg2Â +; Â magnesium; Mnn+; Â manganese; Fen+; Â iron; H+; Â hydrogen; Na+; Â sodium; Al3+; Â aluminium; Zn; zinc; Cu; copper; Co; cobalt; MAP; mean