Sources and doses of zinc on beans and castor beans nutrition and production under intercropping

Abstract

The castor oil is taken by the Brazilian government as the main oilseed for biodiesel production. However, this did not happen because of their low levels of income, especially in the Northeast region, Brazil, where it is commonly grown under intercropping system with annual crops such as common bean. Satisfactory yields only be achieved with real knowledge of nutrient requirements of crops intercropping system participants. Therefore, this study aimed to assess the nutritional and agronomic traits of crops common bean and castor intercropping under different sources of zinc rates. The experimental of randomized block in 2 x 5 + 4 factorial in scheme design, with three replications. The treatments consisted of two sources of zinc (zinc oxide = 15% Zn and zinc sulfate = 20% Zn) combined with five rates of zinc (0.0; 1.0; 2.0; 4.0 and 8.0 kg ha^-1 Zn in soil) intercropping in common bean and castor, plus additional treatments single system common bean and castor, using a rate of 4.0 kg ha^-1 of said sources. It is concluded that fertilization with zinc influenced foliar the phosphorus, calcium, magnesium, manganese content and zinc in these crops in intercropping system, especially zinc sulphate, with the use of zinc sulfate, given its greater solubility compared to zinc oxide. The fertilization with 4.1 and 4.9 kg ha^-1of zinc in soil, lead to the greatest yields of beans and castor under intercropping. The system of intercropping common bean and castor was more effective than the single, for different rates of zinc through fertilizer added.