Late-sown wheat after a late paddy harvest
Ramesh farms 3.2 ha of clay loam in Karnal district. His PR 126 paddy was harvested on 25 November because the combine harvester arrived late, and he now plans to sow wheat on 10 December. He already owns 160 kg of HD 3086 seed, a timely-sown variety he has used for three seasons with 5 November sowing and obtained 4.6 t/ha. The field carries about 4 t/ha of loose paddy straw, which he intends to burn as usual; the soil tests 0.34% organic carbon, pH 7.8 and medium phosphorus. Canal water reaches his outlet once every 12 days, and his tube well gives 2.5 L/s. Diesel costs ₹92/L and labour ₹500/day. He argues that late sowing of HD 3086 is acceptable because he will compensate with extra urea and two extra irrigations, and he wants to save the ₹6,000 he would spend on a custom-hired zero-till drill.
1. He already has HD 3086 in his store. Advise him on variety, seed rate and sowing method for a 10 December sowing, and justify each change.
Read the worked answer
Variety is the first decision, not the urea. HD 3086 needs roughly 155-160 days and is meant for late-October to mid-November sowing. Sown on 10 December, it will flower and fill grain in April, when maximum temperatures cross 35°C; heat shortens grain filling, which is why late wheat yields less even when well fed. Choose a variety expressly listed for late sowing in the Haryana package of practices (short duration, about 140-145 days) rather than HD 3086.
Seed rate. Raise it from 100 to about 125 kg/ha. Late sowing cuts tillering, so the crop must compensate with more ears per unit area; keep rows 18-20 cm apart.
Method. Sow with a zero-till drill straight into the loose stubble instead of burning. This advances sowing by several days, conserves moisture, retains organic matter and saves diesel. Treat seed with a fungicide such as carboxin + thiram, because late-sown wheat is more exposed to seed-borne disease.
2. He plans 180 kg N/ha and five irrigations. Correct his irrigation and nitrogen schedule and explain the risk in his plan.
Read the worked answer
Pull irrigation forward; do not simply add more. The first irrigation should come at 20-25 days after sowing (around 1 January), because crown root initiation arrives earlier in a late crop and January cold is less damaging than February-March heat later. Follow with irrigations at tillering (about 45 days), jointing, flowering and milk - 4-5 in all - and use light, frequent turns in March at 8-10 day intervals if canal rotation allows. Never irrigate during strong wind or in the heat of the day.
Nitrogen. Apply about 120-150 kg N/ha, half at sowing and half at the first irrigation; give the full phosphorus and potash at sowing. Drop the late third split. Nitrogen applied after jointing in a late crop delays maturity and produces soft, lodging-prone plants.
Risk in his plan. Extra urea cannot buy grain-filling time. It increases lodging, aphid attack and heat susceptibility, and it wastes money. The limiting factor is the calendar, not nitrogen.
3. He says the drill is a waste of ₹6,000. Work out what yield the improved package must add to pay for itself, using wheat at ₹2,275/q.
Read the worked answer
Extra cost. Zero-till drill ₹6,000 plus about ₹3,000 more for the late-sown variety seed than for his own seed = ₹9,000 over 3.2 ha, i.e. about ₹2,812/ha.
Break-even. ₹2,812 ÷ ₹2,275 per quintal ≈ 1.24 q/ha, or about 124 kg/ha.
Interpretation. If the package (right variety + zero till + corrected irrigation) raises yield by more than about 1.25 q/ha, it pays. The expected gain from avoiding 10-15 days of delay is several times that figure, so the ₹6,000 saving is a false economy. The decision must be taken for the whole 3.2 ha, not field by field, and the diesel saved by not burning and the organic matter retained are additional, uncalculated gains.