Nutrition, yield and nutrient export in common bean under zinc fertilization in no-till system

Nutrição, produção e exportação de nutrientes em feijoeiro-comum sob fertilização de zinco em sistema de plantio direto

ABSTRACT

Zinc (Zn) is one of the most deficient plant micronutrients in agricultural crops. The objective of this study was to evaluate plant nutrition, grain yield and nutrient export rate in response to soil and foliar Zn fertilization in common bean (Phaseolus vulgaris L.). Two field experiments in no-till system were carried out using two common bean cultivars, BRS Esteio (black bean) and IPR Campos Gerais (Carioca bean). Treatments were composed of soil Zn application during sowing and foliar Zn spray at flowering stage. Soil Zn application had effect on leaf Zn concentration in IPR Campos Gerais and did not affect grain yield of both cultivars. Foliar Zn spray increased leaf Zn concentration by approximately two times in both cultivars, but negatively affected the grain yield in BRS Esteio. Leaf concentration of N, Ca and S were affected by soil Zn application and leaf concentration of Mn was affected by foliar Zn spray, while leaf concentration of P, K, Mg, Cu and Fe were not influenced by the soil and foliar Zn treatments. In treatments without Zn, the descending order of nutrient export rate from the experimental site was as follows: N > K > P > Ca ≈ S > Mg for macronutrients and Fe > Mn > Cu > Zn for micronutrients. Foliar Zn spray increased the export rate of Zn, P, Ca, Mg, S, Mn, Cu and Fe in IPR Campos Gerais, while soil Zn application resulted in higher export rate of P, K and Mn in BRS Esteio.

Index terms:
Phaseolus vulgaris; tropical soil; micronutrient; grain yield