Why are biogas plants considered to be a boon to farmers? Give reasons.

(N/A) Biogas plants are considered to be a boon to farmers for the following reasons:
$(i)$ Farmers obtain a clean fuel that produces no smoke or harmful emissions compared to traditional dried dung cakes.
$(ii)$ The spent slurry,which is the residue left after biogas extraction,serves as an excellent source of organic manure. This manure is produced quickly and can be applied directly to fields,unlike traditional composting methods.
$(iii)$ Biogas plants decompose various organic waste materials that would otherwise cause pollution. This process effectively helps in managing waste and controlling environmental pollution.