How much zinc sulphate per acre: wheat, rice, maize and cotton
The zinc sulphate doses in Punjab's 2026 crop plans, crop by crop: how many kilograms an acre for each grade, when the zinc goes on, when to skip it, and when a spray makes more sense.
Rafiq Ali ShahidFounder, RS Granules
The short answer
Punjab's crop plans give one zinc fertilizer dose for wheat, rice and cotton: 6 kg of zinc sulphate 33% an acre, or 7.5 kg of the 27% grade, or 10 kg of the 21% grade. Maize takes 6 kg of 33% or 10 kg of 21%. The weight changes with the grade, not the crop. Wheat gets it at sowing, transplanted rice within 10 to 15 days of transplanting. Skip it on wheat if the previous crop got zinc sulphate.
On this page 8 questions
Why do Pakistani fields need zinc?
Most crop land on the Indus plains is calcareous: low in organic matter, with free lime that holds the pH between 7.5 and 8.4. A study of Pakistan's soils says these conditions "tend to restrict the phyto-availability of Zn" and other micronutrients.6 Researchers at NARC describe zinc deficiency in cotton and wheat as widespread on more than 3 million hectares of irrigated cotton-wheat soils.7 Rice has a longer record still: hadda, the first micronutrient deficiency recorded in Pakistan, is zinc deficiency in rice.8
How much zinc sulphate does each crop need per acre?
| Crop | 33% grade | 27% grade | 21% grade | When, and with what |
|---|---|---|---|---|
| Wheat | 6 kg an acre | 7.5 kg | 10 kg | At sowing |
| Rice, transplanted | 6 kg an acre | 7.5 kg | 10 kg | Broadcast 10 to 15 days after transplanting |
| Rice, direct-seeded | 6 kg an acre | 7.5 kg | 10 kg | 30 to 35 days after sowing, with the first nitrogen split |
| Rice nursery | 200 g a marla | 250 g a marla | 300 g a marla | Two weeks after sowing the nursery |
| Cotton | 6 kg an acre | 7.5 kg | 10 kg | With boric acid 2.5 kg or borax 3.5 kg |
| Maize | 6 kg an acre | Not listed | 10 kg | With borax, 3 kg an acre |
| Potato | 6 kg an acre | 7 kg | 10 kg | At sowing |
| Sugarcane | 6 kg an acre | Not listed | Not listed | At planting, where zinc is short |
Sources: Punjab wheat plan 2026-27, page 15; rice plan 2026, pages 12 and 18; cotton plan 2026, page 24; maize plan, page 12; potato plan 2025-26, page 5; sugarcane plan 2025, page 10.
The potato plan prints 7 kg for the 27% grade where the other plans print 7.5 kg. The cotton and maize plans give no timing on the dose line, so ask your district Agriculture Extension office when.
Why does the weight change with the grade?
The percentage is the zinc in the bag. Zinc sulphate monohydrate carries about 33% zinc and the heptahydrate about 21%.5 So 6 kg of 33%, 7.5 kg of 27% and 10 kg of 21% each come to about 2 kg of zinc an acre. Weigh a 21% bag at the 33% rate and the field gets about two thirds of its zinc.
That makes the fair price check simple: divide the price of the bag by the kilograms of zinc in it, then compare grades.
When should zinc go on?
Wheat: at sowing
Put the zinc sulphate on at sowing, with boric acid 17% at 2.5 kg an acre, as the wheat plan gives it.1 Our wheat fertilizer plan sets out the rest of the sowing dose.
Rice: nursery first, then the field
In the nursery, two weeks after sowing; the plan says this works where the shortage is mild. In the transplanted field, broadcast it 10 to 15 days after transplanting. In direct-seeded rice, 30 to 35 days after sowing, with the first split of nitrogen.2
Missed it on wheat?
The wheat plan gives a spray at booting instead: zinc sulphate 33%, copper sulphate, ferrous sulphate, manganese sulphate and boric acid, 350 g of each, in 100 litres of water an acre.1
When can I skip zinc?
On wheat, when the crop before it got zinc sulphate: the wheat plan says not to apply it again.1 Note what your previous crop received before you buy. The plans also tell farmers to base fertilizer on a soil analysis from the Agriculture Department's district soil and water testing laboratory.1
Should zinc go on the soil or as a spray?
The crop plans put zinc sulphate on the soil. The wheat plan adds a booting spray only when micronutrients missed sowing, and the cotton plan adds two zinc and boron sprays, 60 and 90 days after sowing.13
FAO notes zinc sulphate is less suited to sprays because it is acidic, and prefers zinc sulphate with some lime, or a chelate such as Zn-EDTA, for foliar use.5 In a global review of 15 wheat studies, sprays raised grain zinc by a median 63% against 19% for soil-applied zinc; those were not Pakistani trials.6 Our chelated zinc or zinc sulphate guide weighs the two.
Working out zinc for your own field? Send us your crop, acres and soil report on WhatsApp.
Ask about zincWhat mistakes waste zinc, and what is safe?
- Weighing a 21% bag at the 33% rate: the field gets about two thirds of its zinc.
- Repeating zinc on wheat after a zinc-treated crop, against the wheat plan.1
- On cotton, spraying at midday: the plan says spray in the morning or evening on the upper leaves, because midday sprays scorch the leaf.3
- On cotton, mixing the zinc and boron spray with an insecticide: the plan says not to.3
Follow the label on any product you use, for its rate and its handling.
From RS Granules
Zinc 10%
Liquid zinc, sprayed on the leaf to correct a zinc shortage quickly. Ask us for its label rate on your crop before you buy.
Questions farmers ask
Is zinc sulphate 33% better than 21%?
Not for the crop. At the plans' weights, 6 kg of 33% and 10 kg of 21% give about the same zinc an acre. Compare the price per kilogram of zinc, and weigh out the rate for the grade on your bag.
How much zinc sulphate goes on a rice nursery?
The Punjab rice plan gives 200 g of the 33% grade, 250 g of 27% or 300 g of 21% per marla, two weeks after sowing the nursery.
Do I need zinc every season?
Not on wheat after a crop that got zinc sulphate: the wheat plan says to skip it then. For other crops, follow your soil report and the crop's own plan.
Sources
- Punjab Agriculture Department, Production Plan Wheat 2026-27 (Urdu), pages 15 and 16. Checked 21 Oct 2026.
- Punjab Agriculture Department, Rice Plan 2026 (Urdu), pages 12 and 18. Checked 21 Oct 2026.
- Punjab Agriculture Department, Production Plan Cotton 2026 (Urdu), pages 24 and 25. Checked 21 Oct 2026.
- Punjab Agriculture Department, Production Plan Maize (Urdu, file dated January 2025), page 12. Checked 21 Oct 2026.
- FAO, Plant Nutrition for Food Security, Fertilizer and Plant Nutrition Bulletin 16, 2006, chapter 5. Checked 21 Oct 2026.
- Joy E.J.M. and others, a study of zinc fertilizer use on wheat in Pakistan, Plant and Soil 411, 2017, pages 139 to 150. Checked 21 Oct 2026.
- Rafique E., Rashid A. and Mahmood-ul-Hassan M., apparent zinc balances in irrigated cotton-wheat Aridisols, Zinc Crops 2011. Checked 21 Oct 2026.
- Rashid A., PARC, micronutrient deficiencies in crops, IFA workshop slides, 2006, slide 3. Checked 21 Oct 2026.
- Punjab Agriculture Department, potato production plan 2025-26 (Urdu), page 5. Checked 21 Oct 2026.
- Punjab Agriculture Department, Production Plan Sugarcane 2025 (Urdu), page 10. Checked 21 Oct 2026.
General guidance from the Punjab Agriculture Department's published crop plans. Follow the label on any product you use, and ask your district Agriculture Extension office when in doubt.
