Vermicomposting process for treating animal slurry in Latin American rural areas

The management of animal slurry is a big issue in low-income rural areas worldwide. Bolivia suffers such issue related to collection, treatment and final disposal since the main solution applied is the final disposal in open dumpsites. The aim of this study is to introduce a feasible treatment of animal slurry in a Bolivian rural area, where about 670 kg of dung are produced per day and disposed of in open areas. The objective is the improvement of the environmental sustainability and human health, providing an alternative solution for encouraging circular economy in developing rural areas. The study is focused on the vermicomposting process, sustainable solution for low-income regions. The analysis was conducted in function of the earthworm breed used locally (Eisenia fetida and Lombricus terrestris) and the application of activated bacteria for improving the process. The mass loss, the treatment time and the growing rate of the earthworms were analyzed. The results suggest that the use of earthworms is appropriate for reducing the treatment time of the composting process. In particular, the use of the Eisenia fetida combined with the application of the activated bacteria could be relevant for reducing 50% of the time required for the process. Moreover, the application of activated bacteria allows improving the growing rate of the earthworms, doubling its number at the end of the treatment. The data obtained could be of interest for other stakeholders who live in similar environmental, climatic and economic conditions.

The management of animal slurry is a big issue in low-income rural areas worldwide. Bolivia suffers this issue related to collection, treatment and final disposal since the main solution applied is the open dumping. The aim of this study is to introduce a feasible treatment of animal slurry in the rural area of Carmen Pampa, where about 670 kg of dung are produced per day and disposed of in open areas. The objective is the improvement of the environmental sustainability and human health, providing an alternative solution for encouraging the circular economy. The study is focused on the vermicomposting process, a sustainable solution for low-income regions. The analysis was conducted in function of the earthworm breeds used locally (Eisenia fetida and Lumbricus terrestris) and the application of activated bacteria (AB) for improving the process. The mass loss, the treatment time, and the growing rate of the earthworms were analyzed. The results suggest that the different breed of the worms allows gaining up to 19 days, while the use of the AB allows saving about 30 days. Moreover, the vermicomposting process reduced the mass of the slurry of about 65% for the swine’s dung and the bovine’s dung, and 90% of the hens’ dung. Finally, experimental evidence shows that the growing rate of the E. fetida is higher than the L. terrestris (F[1,8] = 78, p < 0.05), with an average of about 193%. The data obtained could be of interest for other stakeholders who live in similar environmental, climatic, and economic conditions for improving sustainability.