Biogas
Biogas from rice residue in combination with animal excreta is an
age-old technology in rice growing tropical world. But its use and efficiency has
been declining over the years, although, it has various benefits including
plant nutrient addition to soil. Further, fermented/composted biogas when used
as manure in rice-paddy, generate less CH4 compared to addition of
fresh organic manure. However, escalating fuel price and climate
change/environmental issue may re-stimulate its future.