FARMERS who want to set up a biogas plant but are short of cattle dung -- the primary raw material used by majority of the 12 lakh biogas plants that exist today -- now have an alternative in non-edible oilseeds, which are easily available.

Scientists at the Tata Research Development and Design Centre (TRDDC) at Pune have successfully extracted biogas from oilseed cakes whose oil had been tapped. The scientists have also bred special cultures of dung-residing microbes that increase biogas yield by 2 to 5 times, claims TRDDC executive director E C Subbaro. And the residue of the treated waste acts as an excellent fertiliser.

The seeds being exploited are castor, mohwa, karanj and tobacco. The de-oiled cakes of these seeds are unsuitable for livestock feed because they contain toxic substances, although seeds of karanj and mohwa are sometimes used as manure for their nitrogen content.