DISPONIBILIDADE DE MACRO E MICRONUTRIENTES DURANTE O PROCESSO DE COMPOSTAGEM DE RESÍDUOS ORGÂNICOS

Abstract

Organic waste is of utmost importance in the recovery of degraded areas due to its chemical and physical soil improvement capacity. This study aimed to evaluate the availability of mineral elements in organic compost at 30, 60 and 90 days of composting when compared with the initial compost. The materials used for the composting process were cattle manure, grass pruning, rock dust and phosphorus solubilizing bacteria, which were homogenized in the ratio of 9: 3: 1, respectively, with the purpose of obtaining a carbon / carbon ratio. nitrogen (C / N) close to 30: 1 for optimum composting. The composter used was developed by the Brazilian Agricultural Research Corporation (EMBRAPA). The variables analyzed were hydrogen potential (pH) and mineral analysis of macros (nitrogen, phosphorus, potassium, calcium, magnesium and sulfur) and micronutrients (iron, manganese, copper, zinc and boron). Both pH and mineral analyzes were performed at four times, at 0, 30, 60 and 90 days after the material was inserted in the compost. All micronutrients and macronutrients nitrogen, phosphorus, potassium, magnesium and sulfur had similar behavior. There was a fall at 30 days when compared to the initial zero (0) evaluation, and at 60 and 90 days after the material was inserted in the compost, the mineral elements obtained increasing availability in relation to the initial evaluation. Calcium macronutrient showed a linear decreasing behavior at 30, 60 and 90 days after material insertion in the compost, when compared with the initial evaluation of the compound.