Mustard is one of the most important oilseed crops grown in India, especially in Rajasthan, Haryana, Madhya Pradesh, and Uttar Pradesh. It is a winter (rabi) season crop that needs proper nutrition and irrigation at the right stages to give a good yield. One of the key management practices in mustard cultivation is the application of fertilizers along with the first irrigation, also known as the “first watering” or “first irrigation dose.” This timing is critical because it directly affects plant growth, branching, and seed formation.
1. Importance of Fertilizer at First Irrigation
When mustard seeds germinate, they initially depend on the nutrients stored in the seed and the small amount available in the soil. However, as the plants begin to grow and develop more leaves, their nutrient demand increases rapidly. The first irrigation generally takes place 25 to 30 days after sowing, at the crown root initiation (CRI) stage. Supplying nutrients at this time ensures that the plant gets the required boost for strong root growth and healthy branching.
2. Major Nutrients Needed by Mustard
Mustard requires nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) in balanced proportions for better yield and oil content. Each nutrient plays a specific role:
Nitrogen (N): Encourages vegetative growth, leaf development, and branching.
Phosphorus (P): Promotes root development and early flowering.
Potassium (K): Improves disease resistance, grain filling, and oil quality.
Sulfur (S): Enhances oil content and improves seed quality — it is particularly important in mustard.
3. Fertilizer Recommendation for First Irrigation
The total fertilizer dose for mustard usually depends on the soil type and fertility. However, a general recommendation for irrigated conditions per hectare is:
Nitrogen: 80–120 kg N
Phosphorus: 40–60 kg P₂O₅
Potassium: 40 kg K₂O
Sulfur: 20–40 kg S
Out of the total nitrogen, one-third should be applied at sowing, and the remaining two-thirds during the first irrigation. This split application ensures that nitrogen is available when the crop needs it most, reducing wastage and improving uptake.
At the time of the first irrigation, farmers should apply:
Urea (as a nitrogen source) — about 80–100 kg per hectare.
Single Super Phosphate (SSP) — if not applied at sowing, can be top-dressed to supply both phosphorus and sulfur.
MOP (Muriate of Potash) — can be applied if soil test shows potassium deficiency.
If elemental sulfur or gypsum was not used earlier, this is also a good time to apply it to maintain oil quality.
4. Method of Application
Apply fertilizers in rows or bands near the root zone and irrigate immediately after application. This helps nutrients dissolve in water and move toward the root area for effective absorption. Avoid broadcasting urea on dry soil, as it can lead to losses through volatilization.
5. Conclusion
The first irrigation in mustard is a critical stage for fertilizer application. Providing the right mix of nitrogen, phosphorus, potassium, and sulfur at this time ensures vigorous growth, more pods, and higher oil yield. Balanced nutrition not only boosts production but also improves the overall health and profitability of the crop. Farmers who manage fertilizer and water together effectively at this stage can expect a healthy and high-yielding mustard field.
