Agricultural Engineering

Indian farm tractors are classified by engine power: Mini tractors (<18 HP) — for small holdings and horticulture. Small tractors (18–35 HP) — most common in India (30–35 HP range dominates). Medium tractors (35–50 HP) — for medium to large holdings. Large tractors (>50 HP) — for commercial farms, deep tillage, and combined operations. Most Indian tractors are 2WD; 4WD is gaining popularity for heavy operations. Major brands: Mahindra (largest in India), TAFE, Sonalika, John Deere. Tractor power take-off (PTO) is standardised at 540 RPM for most implements.

Drip irrigation (micro-irrigation) applies water directly to the root zone through emitters — water use efficiency is 85–95%, making it the most efficient method. Used for horticultural crops, sugarcane, cotton, banana. Sprinkler irrigation distributes water in a rain-like pattern — efficiency is 70–80%. Used for groundnut, wheat, vegetables, undulating terrain. Surface irrigation (flood/furrow/border strip) efficiency is only 50–60%. Under PM-KUSUM and PMKSY schemes, drip and sprinkler installation attract 55% subsidy for small and marginal farmers (90% for SC/ST and NE farmers).

Safe moisture content (SMC) for storage — the maximum moisture level below which grains can be stored without significant fungal or insect damage: Wheat: 12%; Rice/paddy: 14% (milled rice 13%); Maize: 12–13%; Pulses (whole): 10–11%; Oilseeds (groundnut, soybean): 8–9%; Mustard/rapeseed: 7–8%. Moisture above SMC promotes fungal growth (Aspergillus, Penicillium), mycotoxin production, and insect pest buildup. FCI mandates maximum 14% moisture for paddy procurement and 12% for wheat.

A combine harvester performs three operations in one pass — cutting, threshing, and cleaning (winnowing). It consists of a cutting header, threshing cylinder (rasp bar or axial flow), concave, straw walker, cleaning shoe (sieves + fan), and grain tank. Field capacity: 3–5 acres/hour for medium combines (e.g., New Holland TC 5.30) in wheat; 2–3 acres/hour in paddy. Header width determines capacity — most Indian combines have 12–16 foot headers. Grain losses should be <3% (grain loss + threshing loss + separation loss). NABARD finances combine harvesters under the Farm Mechanization MBP.

Primary tillage (deep): Mouldboard plough — inverts and aerates soil, buries trash, 15–30 cm depth; best for weed control. Disc plough — for hard, sticky, or stony soils; cuts rather than inverts. Subsoiler — deep tillage 45–60 cm for hard pan breaking. Secondary tillage (shallow): Disc harrow — breaks clods, 8–15 cm; most common secondary tillage implement. Cultivator — stirs soil without inverting, controls weeds. Rotavator (rotary tiller) — powered by PTO, produces fine tilth in one pass; popular in rice-wheat systems. Leveller / blade harrow — final seedbed preparation.

PMKSY (launched 2015) integrates three earlier schemes — AIBP, IWMP, and On-Farm Water Management (OFWM) — under 'Har Khet Ko Pani' (water to every field) and 'More Crop Per Drop' (water use efficiency). The Per Drop More Crop component subsidises drip and sprinkler irrigation: 55% subsidy for general farmers, 90% for small/marginal, SC/ST, and NE farmers. The scheme targets expansion of irrigation coverage and doubling of water use efficiency. Districts are prioritised by water stress levels. NABARD provides refinance to NABARD-affiliated institutions for PMKSY-linked investments.