Nutritional status of common bean and castor bean cultivars in response to intercropping and nitrogen application

One of the many aspects related to intercropping and practically not studied is the fertilization of the crops involved. The nutritional requirement of the species can be modified as a result of the interaction. The objective of this work was to evaluate the nutrition of common bean and castor bean subjected to different forms of the split of nitrogen (N) rate in coverage. Two experiments were carried out in the summer harvests of 2009/2010 and 2010/2011, using a randomized block design, in a 2 x 2 x 6 + 4 factorial scheme, with three replications. The treatments were composed of two common bean cultivars and two castor bean cultivars in intercropping system, combined with six forms of split of nitrogen fertilization coverage. The four additional treatments were composed of the two common bean and castor bean cultivars in monoculture, using the 40 kg ha(-1) of N in coverage. For common beans, the split of 30:70 kg ha(-1) of N increased the concentration of P (32.3%), K (6.0%), Ca (12.1%), Mg (78.5%), S (180.0%), B (17.9%), Cu (35.5%), Fe (3.1%), Mn (9.2%) and Zn (47.9%) in relation to control treatment. For castor beans, the same split increased the concentration of P (43.5%), K (9.4%), Mg (130.7%), S (3.2%), B (15.8%), Cu (28.4%), Fe (37.6%), Mn (40.5%) and Zn (70.2%). Perola and Energia cultivars obtained higher values of leaf nutrients for common bean and castor bean, respectively. Leaf nutrient concentrations were higher in the monoculture when compared to intercropping for both crops.