Effect of lime, phosphorus and micronutrients on the natural nodulation of beans (Phaseolus vulgaris L.)

Abstract

A glasshouse experiment was carried out in order to test the effects of phosphorus (150 ppm P2O5) basic amendment (150 ppm P2O5, 50 ppm K2O and micronutrients) and lime (1 ton CaC0(3)/ha) in the nodulation by natural strains of Rhizobium in dry bean (cultivar Carioca), in 4 different soils of São Paulo State: Mediterraneo, Podzolizado and two Terra. Roxa Estruturada. The nodule dry weight incrased in two soils (Mediterraneo and Podzolizado) due to phosphorus addition, and in Terra Roxa Estruturada due to addition of phosphorus plus lime. The treatment PK + micronutrients provided better plant development, even in the absence of lime, indicating effect of micronutrients and potassium in the soils studied. However, in Terra Roxa soils, the addition of phosphorus was sufficient to increase the foliage dry weight and total N. The total N increased in plants treated with the basic fertilization. The phosphorus addition contributed to a better nodulation (nodule dry weight and number) by natural strains of Rhizobium.