Cow dung, many may know that this thing usually used as organic fertilizer – like any other organic waste. But not only that!
For those of you who already know su-re.co’s program, or have opened this website, surely you know that cow dung is also useful as a raw material for biogas. Yes! Cow manure is one of the best sources of biogas - compared to other animal manure - which is quite available in Bali. Through su-re.co’s biogas system, cow dung converted into gas for stove fuel, and bio-slurry that could be reused as fertilizer. A paper from Mohammad Khan (access here: https://www.hindawi.com/journals/jen/2020/8815484/) explained that methane production as the best fuel comes from cow dung with a yield of 66.9%, followed by sheep dung at 62.1%, and pig manure far below.
Cow manure also can be used as biochar. This was done by Situmeang, Y.P. and Suarta, M. from Agrotechnology Study Program, Faculty of Agriculture, Warmadewa University (access the paper here: https://eudl.eu/doi/10.4108/eai.13-12-2019.2298908). Biochar is a source of fuel and soil repairer that has high economic value. Indonesia alone exported 150,000 tonnes of biochar in 2000. Biochar global market was worth 1.3 billion US Dollars in 2018, with estimated demand at 395,300 tonnes. In the future, the demand for biochar is predicted to increase. Situmeang et al also produce compost as a by-product of the biochar manufacturing process. Suitable for organic farming!
Talking about fertilizers, there are several reasons why cow dung is excellent for organic fertilizer in Indonesia. The first, of course, is because there are quite a lot of them. 1 adult Bali cow can produce 8-10 kg of manure. Second, cow dung has a high ratio of N (Nitrogen): P (Phosphorus): K (Potassium), namely 0.6: 0.2: 0.5. Third, cows digest cellulose well, so that very little of the weed seeds carried into their manure. This can prevent weeds from growing.