FYM (FYM)

Farm Yard Manure (FYM) is the heap-cured mixture of cattle dung, urine, bedding straw, and feed residues collected from Indian rural cattle sheds and matured in open or covered pits for 3–6 months before field application. It is the oldest organic fertilizer in Indian agriculture and remains the dominant nutrient input for smallholder farms — roughly 250–400 million tonnes are produced annually across the country, mostly recycled within the same village rather than entering formal markets.

Typical FYM composition on fresh-weight basis is 0.4–0.8% N, 0.15–0.3% P₂O₅, and 0.4–0.7% K₂O, with 60–70% moisture and a C:N ratio of 20–25. This is markedly lower in nutrients than digested or composted output, because open-pit curing loses 30–50% of the initial nitrogen as ammonia volatilisation and another 10–20% through leaching during monsoon. FYM also varies widely in quality depending on cattle diet, bedding type, and curing duration — a fact that complicates its use as a CBG feedstock where consistent VS (volatile solids) content matters.

FYM serves a dual role in Indian CBG economics. As feedstock for village-scale digesters (1–25 m³ family units) and SATAT-scheme plants (10–200 TPD), it offers a reliable, dispersed raw material at ₹400–800 per tonne delivered. It also competes with digestate at the farm gate — farmers will only buy Fermented Organic Manure if it offers a clear advantage in nutrient density (3–5× FYM), pathogen-free certification, or easier application. CBG plants that fail to differentiate their digestate from local FYM typically struggle to clear ₹2,000 per tonne ex-plant, while well-marketed pelletised FOM commands ₹6,000–10,000 per tonne.

• India produces 250–400 million tonnes of FYM annually, mostly used within source villages.
• Typical composition: 0.4–0.8% N, 0.15–0.3% P, 0.4–0.7% K on fresh basis.
• Open-pit curing loses 30–50% of initial nitrogen — sealed pits cut this in half.
• FYM is both raw material for digesters and the price benchmark digestate must beat at the farm gate.