Manejo da adubação nitrogenada em cobertura no sistema consorciado feijão comum e mamona, na região do Cerrado

Abstract

This study aimed to assess the form of installments of N for different cultivars of common bean and castor intercropping in two years of cultivation. Experimental design used was of randomized complete block in 2 x 2 x 2 x 6 + 4 factorial scheme a addicional six treatments, with four replications. The treatments consisted of two crop seasons (2009/10 and 2010/11), two cultivars of bean (BRS Pontal and BRS Pérola), two castor bean cultivars (BRS Energia and BRS Paraguaçu), combined with six forms of fertilization N of cover: without application; 100 kg ha-1 applied at 25 days after emergence (DAE); 100 kg ha-1 at 35 DAE; 30 and 70 kg ha-1 applied at 25 and 35 DAE, respectively; 70 and 30 kg ha-1 applied at 25 and 35 DAE, respectively; 50 and 50 kg ha-1 applied at 25 and 35 DAE, respectively. The additional treatments were composed of four cultivars in monoculture. Were evaluated the efficient use of soil (EUS); the foliar concentrations of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn for both crops; and the following agronomic characteristics: number of pods per plant, number of seeds per pod, hundred grain weight, yield and plant height for the common bean; and number of racemes per plant, number of fruits per raceme, hundred grain weight, yield and plant height for the castor. Data were subjected to analysis of variance and where appropriate was carried out the test of comparison of means Scott-Knott (5%). The crop in 2009/10 using nitrogen coverage 30:70 kg ha-1, caused higher concentrations of P, Ca, Mg, Cu, Fe, Mn and Zn; beyond agronomic characteristics found for both crops under intercropping. In intercropping, the Pérola and Energia cultivars presented higher levels of nutrients for the common bean and castor respectively. For both crops the nutrient contents were higher in monoculture than in the intercropping. Except height, common bean monoculture showed higher values of agronomic traits in relation to the intercropping. There was no influence of cropping system on the agronomic characteristics of castor. The soil use in the intercropping is more efficient than in monoculture (EUS= 1,64)