Biofertilizer production by vermicomposting of organic wastes

Abstract

The adequate destination to wastes generated on farms is the great chalenge for rural producers. The composting and vermicomposting processes are two sustainable alternatives. In the first, the metabolism of aerobic chemorganotrophic microorganisms is used to oxidize organic matter, generating a residue that can be incorporated into the soil, improving the soil physical-chemical properties and consequently increasing the rural productivity. The second alternative is vermicomposting, in which the process is optimized with the insertion of earthworms in the substrate, generating a richer organic residue due to the combination of the earthworm metabolism with the microorganisms. The great advantage of vermicomposting is the reduction in composting time, and the subsequent use of the waste generated as a biofertilizer, since it contains millions of bacteria and biologically active enzymes and is a great source of humic substances and nutrients for plants having five times more nitrogen and seven times more potassium than a soil. The major difficulty in working with solid waste is the logistics involved, since very large amounts of soil application are necessary to achieve the desired effect on productivity, which involves costs with transportation, fuel and specific machinery. However, it is possible to liquefy vermicomposting products, with the advantages of reducing transportation and fuel costs, since the waste can be diluted and sprayed along with irrigation water, and does not require a large volume of application in the field. This liquid extracted in the composting processes is composed by thousands species of fungi and soil bacteria, protozoa and various components of the microfauna and by humic substances. These biological and chemical components can act in processes of disease suppression, decomposition of organic matter, biological nitrogen fixation, mycorrhiza formation and nutrient cycling control. Given these facilities and benefits that liquid vermicompost can provide, as attested in greenhouse and field tests, we intended to generate effective results that show that it can improve plant development and, consequently, increase agricultural productivity, making it an innovative product, with great performance in the physical, chemical and biological conditioning of the soil and able to compete with mineral fertilizers, minimizing the use of these, promoting the increase of productivity sustainably. Therefore, we propose simultaneously to process and recycle organic waste generated by rural properties and consequently the creation of a product that increases agricultural productivity and increase the soil quality, with cost reductions for rural producers. (AU)