Eficiência do uso de organomineral associado a aplicação de rizóbios em cobertura no desenvolvimento e na produtividade do feijão

Abstract

The increase in the generation and incorrect destination of waste from human activities have become a worldwide environmental problem. In Sewage Treatment Plants (STP) the final destination of sludge generated in the treatment process is a limitation, and its use in agriculture presentes itself as a destination that can contribute to the sustainability of the sludge treatment process and agricultural production. Organomineral fertilizers are the result of mixing organic compost with mineral fertilizer and their use in agriculture has shown positive results. Thus the aim of this study was to investigate the efficiency of the using sewage sludge as an organic base in the formulation of organomineral compost associated with the use of rhizobia mulch application in the development, nutrition and productivity of bean crop. A 4 x 2 + 1 factorial design with four repetitions was used in a randomized block design, with four treatments consisting of four doses of organomineral (0, 50%, 100%, 150% of the nutritional recommendation of the crop), with and without the application of rhizobia as cover, plus an additional treatment with 100% mineral fertilization. The morfological variables analyzed were: leaf area index,accumulation of fresh and dry biomass, plant height, stem diameter; nutritional variables: nitrogen, phosphorus, potassium, calcium, magnesium, copper, iron, zinc and manganese at flowering, and yield components: number of pods per plant, number of grains per pod, weight of 100 grains and crop yield. The data were submitted to analysis of variance (p≤0.05), and when significant the means from the qualitative treatments were compared by Tukey's test 5% probability, while in quantitative treatments regression analysis was applied. Under the development conditions of this research, it is concluded that the use of organo-mineral fertilization based on sewage sludge promoted the improvement of most developmental, nutritional and agronomic variables of the bean, compared to mineral fertilization. The adequate dose of organomineral to be added to the base is 100% of the nutritional recommendation; a dose higher than this causes decreases in some developmental and nutritional variables of the bean. The application of rhizobium was not efficient in promoting increases in grain yield.