RECYCLING OF CATTLE MANURE ASSOCIATED WITH RICE HUSK AS VERMICOMPOST VIA THE EISENIA FÉTIDA EARTHWORM

Agro-silvopastoral residues such as cattle manure and rice husks are abundant in the southeastern region of Pará. As an alternative aimed at sustainability, recycling through vermicomposting has advantages such as low cost, easy and fast application, besides the production of a material rich in nutrients. The objective of the work was to analyze the use of the vermicomposting technique in the degradation of agroforestry residues for the construction of organic fertilizer. The research method used was hypothetical-deductive, of quanti-qualitative scope under applied nature and descriptive, exploratory and experimental procedures, with standardized techniques of data collection and systematic observation on the processes of the study. Within this, the study followed within a greenhouse environment under open sides, located in the back of the Pará State University, Marabá campus, Pará. The materials used were rice husk from a rice mill in the municipality, along with black soil and bovine manure. For the initial stages, the manure needed to go through a washing process (tanning), and the rice husk by carbonization of the material, transforming it into ash. A pre-composting was performed for a period of 36 days before the increment of Eisenia fétida earthworms. The experimental design was employed with the use of 4 treatments, T1 - Cattle manure + rice husk in natura + Soil (composted), T2 - Cattle manure + rice husk in natura + Soil (Vermicompost), T3 - Cattle manure + rice husk ash + Soil (composted), T4 - Cattle manure + rice husk ash + Soil (Vermicompost). To measure pH and temperature data, the AMT-300® equipment was used, while soil moisture was measured using a soil hygrometer sensor connected to the Arduino UNO R3 board. At the end, samples of the organic compost were analyzed in the soil laboratory of Embrapa Amazonia Occidental, with data submitted to descriptive statistics and comparison of means using the Tukey 5% test. The pre-composting required 36 days, a period considered long due to the problem of assembling the beds during the rainy season in Marabá. They had pH values suitable for worm casting (5.5 - 6.9) and temperatures < 30°C, considered suitable environments for the development of Eisenia fétida. T2 and T4 presented a significant difference in moisture and chemical composition compared to T1 and T3, with moisture levels above 70% and organic matter contents 40% higher. T4 was the one with the highest C/N ratio, with values higher than the other treatments. The nutritional gain observed in the organic composts from vermicomposting in the pilot experiment, supports the need for implementation of vermicomposting on a larger quantitative scale in the evaluation of the of Eisenia fetida earthworms and their potential for degradation of agroforestry residues, resulting in ecological alternatives for the southeastern region of Pará.