Cuantificación emergética ambiental en la producción de lombricompost

Traditional market research about the vermicompost includes cost-benefit analysis without considering environmental variables. Thus, they do not represent the real value of the impacts generated in these processes. The elaboration of vermicompost may affect the environment if during its production process it consumes more resources than their provided benefits. The aim of this research was to determine the environmental emergy and the contents of organic matter (OM), phosphorus (P) and potassium (K) in vermicompost production from bovine, rabbit and pig manure. This study was performed at the Inconfidentes, Instituto Federal de Educación, Ciencia y Tecnología del Sur de Minas Gerais, Brazil, from November 2014 to January 2015. Our hypothesis was that the vermicompost that uses more market resources will have a lower sustainability index. The renewable (R), non-renewable (N) and economic (F) resources employed to produce three vermicompost were assessed and their energetic indexes were obtained: emergy yield (EYR), environmental charge (ELR), sustainability (ESI) and percentage of resources (% R). In the experimental design, OM, P and K content was determined in 10 samples randomly taken. Results were analyzed with an ANOVA and the Tukey test of means (p≤0.05). The EYR, ELR and ESI index and % R obtained were: for bovine vermicompost 3.16, 0.315, 10.06 and 68.44 %, for rabbit vermicompost 8.69, 0.13, 66.80 and 88 %, and for swine vermicompost 5.02, 0.249, 20.20 and 80.00 %. The vermicompost produced from rabbit manure was the most long term sustainable process, compared to the others. The average OM, P and K content from the rabbit vermicompost was of 35.14, 0.76 and 1.99 % each, and outperformed the both, the bovine and porcine vermicomposts.