Agricultural Engineering and Farm Machinery: Tillage, Irrigation and Water Measurement
This domain tests tillage implements, seed drills and harvesters, tractor power, irrigation methods and soil and water conservation structures, with simple numerical work on water volume.
Tillage and machinery
Primary tillage opens the soil: mouldboard plough, disc plough, chisel plough. Secondary tillage refines the seedbed: disc harrow, cultivator, leveller. A seed-cum-fertilizer drill places seed and fertilizer together at depth; a thresher separates grain from straw; a combine harvester does cutting and threshing in one pass. Tractor power is rated in horsepower at the power take-off, which drives pumps and threshers.
Irrigation and conservation
Drip irrigation is the most efficient, followed by sprinkler, then surface flooding. Conservation structures include contour bunding on gentle slopes, terracing on steep land, check dams in gullies and farm ponds for storage.
Worked example
A plot of 1 hectare is to receive 6 cm of irrigation water. 1 hectare = 10,000 m²; 6 cm = 0.06 m; volume = 10,000 × 0.06 = 600 m³. Since 1 m³ = 1,000 litres, that is 6,00,000 litres. If the pump delivers 30 m³ per hour, the run time is 600 ÷ 30 = 20 hours. Note the standard conversion: 1 hectare-centimetre equals 100 m³.
Traps
- Forgetting to convert centimetres to metres, giving an answer 100 times too large.
- Calling drip irrigation wasteful; it is the most water-efficient method.
- Confusing a cultivator with a harrow, or a thresher with a winnower.
- Using contour bunds on steep slopes where terraces are required.