Calcário, Potássio, Fosfato e Silício na produtividade do solo

Abstract

A sorption study was performed in order to seek improvement on phosphorus availability in soil, using CALPOT (lime + potassium) and silicon as promoters. P and Si were applied in laboratory, at crescent dosages, in soil and CALPOT was used to reach base equilibrium for 50% Ca, 10% Mg and 3% K, using lime and potassium. Soil samples were incubated in a green house with seven treatments, being 1) control; 2) CALPOT + P + Si; 3) CALPOT + P; 4) CALPOT + Si; 5) Si + P; 6) lime; 7) CALPOT. Basic cations were applied in the same dose established for laboratory, P with 50 mg kg-1 and Si with twice the P-dose. It was observed that the complete treatment in laboratory reduced P adsorption in the studied soil. In the greenhouse, the complete treatment established bases balance and increased P availability in the soil. The co-application of these elements made possible smaller P adsorption, improving the soil's chemical properties.