PRODUCTIVITY OF CASTOR BEAN IN RESPONSE TO FERTILIZATION WITH SEWAGE SLUDGE

Sewage sludge, waste from the stations of wastewater treatment, has high contents of organic matter and nutrients and, when stabilized, it presents enormous potential for agricultural use. This study aimed to evaluate the effect of doses of sewage sludge on growth and yield of castor bean. The experiment was conducted in Cambisol, using the cultivar Guarany AL 2002. The treatments in a randomized block design with four replicates, corresponding to a treatment with chemical fertilizer (90 kg ha(-1) of P2O5 and 30 kg ha(-1) K2O at planting and 40 kg. ha(-1) N, 40 days after planting), and five doses of dry sewage sludge (0, 15, 30, 45 and 60 t ha(-1)). At the end of the cycle, the assessments were made of stem diameter, plant height and productivity. The productivity of seeds and the biometric characteristics of castor bean increased with increasing doses of sewage sludge applied to soil, and the dose from 15 t ha(-1) is sufficient for replacement of mineral fertilization of culture without the risk of soil contamination with heavy metals.