Compostagem em pequena escala e uso do composto como substrato na germinação de sementes de tomate (lycopersicum esculentum).

Abstract

Composting processes have established themselves as efficient procedures for minimizing environmental issues and reducing the volume of discarded organic solid wastes. This work aims at studying small scale composting processes as a useful alternative for tackling agroindustrial residues issues in a semiarid region of Paraíba State, Brazil. For this, two compost piles were set (one placed on compacted soil and the other one on a concrete patio) and monitored by observing parameters such as temperature, moisture, pH, reduction in dry matter and volatile solids for 73 days. The maturity was assessed by the C/N ratio, electrical conductivity, and chemical oxygen demand. The characterization of the final compound was carried out by using total nitrogen, pH, moisture and C/N ratio. The produced compounds were also used to check the germination of tomato considering various proportions (0%, 10%, 20% and 40%) of compound mixed with a regional soil. As the composting process conducted on the patio, the treatment on soil also achieved temperatures between55 and60°C during the process. As for the volatile solids, the compounds produced directly on soil out performed those obtained on concrete patio, with reduction of its initial value of about 69.94%.The results suggest that the studied organic compounds were maturated at 73 days of cure, indicating that the application of simple methods is considered to be safe for verifying composting processes. The compounds based on agroindustrial wastes reached almost all the requirements requested by Brazilian law. Regarding to the performance of tomato germination, the substrates obtained from the soil-based compounds outperformed those using the compounds produced in concrete patio. The small scale composting processes were shown to be effective for treating agroindustrial wastes in semiarid Paraíba, Brazil, and the derived substrates have proved to be suitable for germination of tomato.