Comparative study among the chemical factors of the A and B2 horizon of two soils, on the common bean (Phaseolus vulgaris L.) yield

Abstract

Experiments were carried out in greenhouse, at ESALQ-USP, in Piracicaba, Brazil, with soil samples of the A and B2 horizon of Oxisol (LR) and an Alfisol (PVp), without and with lime and mineral fertilizer, to verify which are the chemical-nutritional factors in deficiency in the B2 horizon of both soils, compared with the A horizon, and which need to be considered for the adequate exploration of the genetical harvest potential of the common bean cv. Aroana 80. It could be verified that the base saturation and the consequent reduction of the Al saturation was not enought to reach an adequate grain yield. Trough the evaluation of the relative contents and the relations between the absolute nutrient contents in the dry matter, it could be verified the importance of the relative content of P and Mg, and the P/Zn, N/Zn, Mg/Cu and P/Fe relations, besides other to soil specific nutrient levels and relations. In the limed and fertilizer soils the micronutrients must be considered, and also the organic matter in the B2 horizon, which appeared with levels below the necessary to supply the humusclay complex.