Tratamento de camas de equinos por compostagem e vermicompostagem

Abstract

The treatment of agricultural and livestock waste is becoming an issue for those farmers who keep theirs animals in confinement. As the country scenario is favorable to horse culture, farmers seek for alternatives to dispose correctly saturated bedding, normally made out of waste from another activity, which is able to absorbs manure and urine at animals‟ stalls. Composting and vermicomposting stand out as treatments for organic waste, especially manure, due to resulting of more stabilized organic matter, also being low cost techniques in relation to implementation and management. Thereby, this study aimed to analyse the treatment of five horse bedding by means of these two techniques. The treatments consisted in horse bedding made of: T1 – coffee peel (bean parchment); T2 – sawdust; T3 – sawdust and brachiaria; T4 – rice straw; T5 – rice straw and brachiaria. The treatments were placed at the stalls and remained until saturation. As soon as the waste was removed, it was windrow-shaped pre-composted, for 42 days. Physical parameters such as temperature, volume and weight reduction, and physicochemical parameters, such as pH, electric conductivity, solid series, Total Organic Carbon (TOC) and Total Nitrogen (TN) contents and C/N ratio, were monitored. After this period, 15 vermireactors, 3 for each treatment, were built and the remaining material was left windrowed, in order to continue the composting process. The same parameters analysed for the pre-composting period were again analysed for the development of composting and vermicomposting, which lasted for 58 days. The results showed that both the Vermicomposting Composting as for the treatments T2 and T3 presented total decharacterization from original material. Treatments T4 and T5 demonstrated, respectively, no and little organic matter degradation. Regarding the parameters analysed, it is mainly important to highlight that treatment T1 is not tolerated by earthworms, and consequently, vermicomposting is not indicated. Regardless the waste which brachiaria is added to and the applied technique, it improves the conditions for waste treatment as it increases the aeration, supplies easily degradable carbon and assists nitrogen mineralisation. Therefore, for application at large scale, it is recommended the sawdust and brachiaria consortiated treatment, utilising the composting technique, since it presented the best features and easiness of being executed and obtained at a rural property.