Principle of Aquaculture (1+1)

Limitation

Although widely promoted as an appropriate technique for use in aquaculture systems, there is very little evidence that biogas slurries have been used by individual households on a sustainable basis. The systems that were demonstrated were experimental. Biogas digester designs have evolved. The conventional types promoted in India were too capital intensive for adoption by poorer people. The low rates of adoption suggest that these digesters did not meet peoples' needs. Research at AIT in Bangkok, Thailand, suggests that the technical benefits from digesting waste were marginal or negative.

The system, as described may be more useful for commercial-scale livestock farm operators intending to integrate aquaculture into their farming system.

Experiences with biogas digester technology dissemination have been that this is a clustered technology which is best operated with several households sharing one system, to provide adequate levels and continuity of waste input. Recent developments in digester design have made simpler, very low-cost systems available. In southern Viet Nam, where these cheaper types of digesters were promoted and their adoption was monitored, the retention of the technology within aquaculture has been poor. Farmers prefer to use their livestock waste fresh.

Additional benefits of the system will accrue to women by providing biogas for cooking.