The objective of this research was to evaluate the growth and production of castor bean (Ricinus communis L.) BRS Energia in rainfed cultivation under combined fertilization of castor bean bark in a natural and ground forms and with increasing levels of nitrogen. The experiment was conducted during September, 2009 to March, 2010, at Campus IV/UEPB. The planting was done in 60 L pots filled with 58 kg of soil. Using a randomized block design in a 2 x 4 factorial, with two kinds of bark of castor bean (natural and ground) in the dose of 3 t ha-¹ and four rates of nitrogen (0, 30, 60, 90 kg ha-¹) with four replications. It was verified that fertilization with the ground bark was superior than natural bark. For the dry mass of the bunch, leaf area per plant, and leaf number, dose of 90 kg ha-¹ of N was better than the others. While for the number of nodes the dose of 60 kg ha-¹ of N was better. The bark of castor bean used in a rational way, as fertilizer, contributes to reduce cost of production and increases the soil fertility.
semi-arid; Ricinus communis L.; fertilization
