Increased quality of small-scale organic compost with the addition of efficient microorganisms

Abstract

Substantial quantities of solid livestock waste are potential sources of nutrients for agroecological production on small-scale farms. However, processes used to manage and dispose of this type of waste must be able to eliminate pathogenic microorganisms. This work aimed to evaluate composting and vermicomposting processes by inoculating efficient microorganisms (EMs) at the field level. Composting and vermicomposting were performed with a mixture of cattle and goat manure and sawdust (2:1:1), with the inoculation of EMs at concentrations of 0, 2, and 4 mL L-1. In vermicomposting experiments, Lumbricus rubellus (100 g 250 dm-3 substrate) were inoculated. After the maturation and stabilization phases of the compost, concentrations of organic carbon, macronutrients, micronutrients, heavy metals, thermotolerant coliforms, and Salmonella spp. were analyzed. The composting experiments, regardless of the presence of EMs, have been shown to have higher humidity. Also, the final compost had a lower pH value. Macronutrients, such as P, K, Ca, and S, were observed to a greater extent in the composting experiments associated with 4 mL of EMs (EM4); while organic carbon and Mg were higher in vermicomposting. The vermicomposting process also allowed for more effective elimination of pathogens, such as thermotolerant coliforms, especially when associated with 2 mL of EMs (EM2). The compost products produced allowed waste with potential agroecological use to be recognized as important.

Keywords

• vermicomposting
• waste recovery
• pathogens
• organic fertilizer