Biogas production from pretreated wheat straw, lantana residue, apple and peach leaf litter with cattle dung.

The contribution of alkali-treated plant residues as a supplement to cattle dung (1:1, w/w at 10% slurry level) for biogas production and quality was evaluated. Addition of pre-treated (1% NaOH for 7 days) lantana residues, wheat straw, apple leaf litter and peach leaf litter to cattle dung improved microbial digestibility and biodegradability during anaerobic fermentation at ambient temperature (28–31° C). Higher biodegradability of organic matter and cellulose was achieved in pretreated plant residue supplemented slurries. There was an almost twofold increase in biogas and methane production with plant residues, highest in lantana supplementation, as compared to cattle dung. Lantana slurry gave 63·6% methane in the biogas; apple leaf litter, 59·6%, wheat straw, 58%, and peach leaf litter, 57·7%, against cattle dung, 56·1%. The digestion efficiency in terms of biogas release per gram of dry matter with pretreated plant residues was 341–372 ml g−1, 31–42% higher than cattle dung.