Dear wheat farmers,
Let’s focus together on the most important agricultural practices for wheat, including irrigation, fertilization, and weed control, to achieve the highest possible yield.
Irrigation:
Irrigation plays a crucial role in obtaining a high wheat yield. In the northern regions, wheat requires about 4–5 irrigation cycles in addition to the initial planting irrigation. It is essential to apply this initial irrigation carefully, as excessive water can cause seed cracking, while insufficient water can dry them out, leading to a lower germination rate.
Subsequent irrigations should be done lightly. The first post-planting irrigation (known as the “tillering irrigation”) should be given approximately 21 days after planting. It must not be delayed beyond 25 days unless heavy rainfall occurs. Afterward, irrigation should be applied every 25 days, ensuring the plants do not experience drought stress, particularly during tillering, spike emergence, and grain formation stages. However, excessive irrigation should also be avoided.
Fertilization:
Organic Fertilization:
The addition of organic fertilizers improves soil properties. It is recommended to use well-decomposed and aged manure from a reliable source to avoid weed seeds, nematodes, insect larvae, and disease pathogens. The recommended rate is 20 cubic meters per feddan (approximately 200 carts). When using organic fertilizers, the chemical nitrogen fertilizer requirement should be reduced by 15 kg of nitrogen per feddan.
Chemical Fertilization:
- Phosphatic Fertilization: Apply superphosphate at a rate of 15 kg P₂O₅ per feddan, spread evenly before the final soil preparation. This is equivalent to:
- 100 kg of 15% phosphate fertilizer
- 40 kg of 37% phosphate fertilizer
- 33 kg of 45% phosphate fertilizer
- Potassium Fertilization: Apply 50 kg of potassium sulfate during land preparation.
- Nitrogen Fertilization: Apply nitrogen at a rate of 75 kg of nitrogen per feddan, equivalent to:
- 163 kg of 46% urea
- 224 kg of 33.5% ammonium nitrate
- 364 kg of 20.6% ammonium sulfate
Nitrogen fertilizer should be applied in three doses:
- First dose (20% of the total amount): Applied at planting, before the initial irrigation, especially in weak soils.
- Second dose (40% of the total amount): Applied at the first irrigation. If the initial dose was skipped, 60% should be applied at this stage, particularly in fertile soils.
- Third dose (40% of the total amount): Applied at the next irrigation when the plants are in the grain-filling stage. It is crucial to apply nitrogen at the recommended times to maximize yield. No fertilizer should be added after spike emergence, as it will not contribute to yield improvement. Additionally, fertilizers should not be mixed; each type should be spread separately and immediately before irrigation. Delaying fertilization until the day after irrigation, as some farmers do, is not advisable.
Farmers can assess wheat nitrogen needs by observing plant color: pale green or yellowing plants require nitrogen, while dark green plants do not need additional fertilizer.
Nitrogen Fertilization Using Gaseous Ammonia:
In this method, the entire nitrogen requirement is applied via injection below the soil surface in a single dose about four days before planting. The soil should be well-prepared, and the ammonia is injected after soil preparation. The land should remain undisturbed for four days before planting and initial irrigation.
For fields with high weed infestation, chemical weed control should be performed before ammonia application. Phosphate fertilizers should also be incorporated during soil preparation. It is crucial not to delay wheat planting after ammonia injection to prevent nitrogen loss.
Benefits of Using Gaseous Ammonia:
- Reduces labor requirements
- Ensures even fertilizer distribution, leading to uniform plant growth
- Increases yield by approximately 14% compared to other fertilization methods
Addressing Phosphorus Deficiency:
Sometimes, plants weaken at around 40–50 days after planting, especially if the first irrigation was delayed. This manifests as yellowing of older leaves due to phosphorus deficiency. In such cases, immediate irrigation is required, along with the application of 100 kg of superphosphate or 5–6 liters of 80% phosphoric acid. A week after irrigation, foliar spraying with a high-phosphorus fertilizer containing amino acids and essential micronutrients (iron and zinc) should be performed.
Irrigation & Fertilization for Wheat Under Pivot Sprinklers:
- At planting: Apply 40 kg of DAP (46-18-0) with the seeds using a planting machine to encourage root establishment.
- At day 14: Spray 1 liter of Carbendazim fungicide per hectare, adjusting the pivot speed to 100.
- At day 15: Stop irrigation for two full days before fertilization.
Fertilization Schedule via Irrigation System:
- Day 18: Broadcast the remaining DAP (46-18-0) along with 40 kg of urea + 40 g of potassium sulfate.
- Day 25: Apply 20 kg of urea + 2 liters of liquid fertilizer (0-34-52 phosphoric acid).
- Day 30: Apply 20 kg of urea + 2 liters of phosphoric acid (0-34-52) + 1 kg of micronutrients (iron, zinc, manganese).
- Day 35: If broadleaf or grassy weeds appear, apply a selective herbicide.
- Day 40: Apply 20 kg of urea + 1 kg of micronutrients + 2 liters of phosphoric acid (0-34-52) + 3 kg of potassium sulfate.
- Day 50: Apply 20 kg of urea + 2 liters of phosphoric acid (0-34-52) + 6 kg of potassium sulfate.
- Day 55: Apply 20 kg of urea + 2 liters of phosphoric acid (0-34-52).
- Day 57: Apply 150 ml/acre of Bavistin fungicide via the irrigation system as a preventive measure before spike emergence.
- Day 60: Apply 20 kg of urea + 1 kg of micronutrients + 2 liters of phosphoric acid (0-34-52) + 6 kg of potassium sulfate.
- Day 70: Apply 20 kg of urea + 2 liters of phosphoric acid (0-34-52) + 6 kg of potassium sulfate.
- Day 80: Apply 20 kg of urea + 2 liters of phosphoric acid (0-34-52) + 7 kg of potassium sulfate.
- Day 90: Apply 10 kg of urea + 2 liters of phosphoric acid per hectare + 6 kg of potassium sulfate.
- Day 100: Apply 10 kg of urea + 2 liters of phosphoric acid (0-34-52) + 5 kg of potassium sulfate.
- Day 110: Apply 4 kg of urea + 5 kg of potassium sulfate.
- Day 115: Apply 3 kg of urea.
By following these irrigation and fertilization guidelines, wheat farmers can optimize growth, improve plant health, and achieve a higher yield.
Written by: Smart Land
