Dinâmica da decomposição dos resíduos orgânicos da produção de agroenergia e sua utilização em sistemas de cultivos de base ecológica

Abstract

Alternatives oriented production systems with lower costs, risks and environmental damage are increasingly necessary. However, one of the main difficulties encountered by farmers is the availability of organic inputs, including, fertilizers able to provide satisfactory yields while enabling improvements in soil quality. This study aimed to evaluate the use of residues from agro-energy production as a source of organic fertilizers from the use of castor bean pies and tung in family farming systems ecological base. The experiment was conducted from spring 2010 to autumn 2012, in the experimental area of Estação Experimental Cascata da Embrapa Clima Temperado, Pelotas, Rio Grande do Sul. The experimental design was a randomized block with four replications. For production work potato treatments consisted of applying pies castor and tung, at doses of 50, 100 and 200% of the recommendation for the cultivation of potatoes and two witnesses, with and without chemical fertilizer. For the work of decomposition of organic waste and nutrient release treatments consisted of two residues (castor cake and pie tung), two rooms (for field and greenhouse), two sizes of bags decomposition (0.2 x 0.2 m (big bag) and 0.15 x 0.07 m (small bag)) and decomposition nine periods (0, 7, 14, 21, 28, 45, 60, 90, and 120 days). The use of waste pies castor and tung led to the following inferences: fertilization with pies castor and tung in dosages of 100% recommendation led to the best total and commercial yield of potato tubers; pies castor and tung, the dosages that enabled better productivity results not demonstrated negative effect on soil insects causing damage in potato tubers; pies castor and tung, the dosages that allowed higher yield of potato tubers, provided no changes in the chemical soil during the growing cycle of the potato, castor bean residues decompose faster than waste pie tung; pies castor and tung had two distinct phases of decomposition and nutrient release; being a quick at the beginning of the provision of material until 15 to 21 days of disposition, and a slower, extend up to the end of the study.