The use of dung as raw material for biogas production is profitable than using it only as fertiliser or fuel.

Explanation

Animal dung is used as raw material for production of biogas. It provides a safe and efficient method of waste disposal.
`rarr` Besides it, by supplying biogas as a fuel gas, cooking, lighting, etc. we can save natural gas.
`rarr` The residual slurry can be used as excellent manure that is rich in nitrogen and phosphorous.
This natural fertiliser maintains soil fertility and agriculture practice becomes more economical.