Which Fertilizer Increases Cotton Yield? What Farmers Need to Know This Season

 Cotton productivity in India is under renewed focus as input costs rise and weather patterns turn unpredictable. Agronomists and state agriculture departments are advising farmers to move away from blanket fertilizer use and adopt crop-stage and soil-specific nutrition. The key message this season is clear: cotton yield improves not from one single fertilizer, but from the right combination applied at the right time. Balanced use of nitrogen, phosphorus, potassium, and critical micronutrients is now seen as the most reliable way to increase boll formation, fibre quality, and overall yield.

Below is a practical, field-tested breakdown of which fertilizers actually increase cotton yield—and how to use them correctly.

                                              

Nitrogen (N): Drives Growth, But Needs Control

Nitrogen remains the most important nutrient for cotton, especially during early vegetative growth and square formation.

Common nitrogen fertilizers for cotton:

• Urea (46% N)

• Ammonium sulphate (21% N + sulphur)

• DAP (18% N, also supplies phosphorus)

Why nitrogen matters:

• Promotes leaf development and plant height

• Supports early canopy formation

• Directly impacts boll number

What has changed:
Experts now caution against excessive nitrogen. Overuse leads to:

• Excess vegetative growth

• Delayed flowering

• Higher pest pressure (especially sucking pests)

Best practice:

• Apply nitrogen in split doses (basal + top dressing)

• Avoid late heavy nitrogen after flowering

• Base dosage on soil test results

Phosphorus (P): Strong Roots, Better Boll Setting

Phosphorus plays a critical role in root development and early plant establishment.

Recommended phosphorus fertilizers:

• DAP (Di-ammonium phosphate)

• SSP (Single super phosphate)

• Complex fertilizers (like 20:20:0)

Yield impact:

• Improves root strength

• Enhances flower initiation

• Reduces early crop stress

Current advisory trend:
In many cotton-growing belts, soil phosphorus is either locked or underutilized. Applying SSP instead of DAP is gaining attention because SSP also supplies sulphur, which cotton increasingly needs.

Potassium (K): Essential for Boll Development and Fibre Quality

Potassium is now considered a yield-limiting nutrient in many cotton fields, especially in long-duration hybrids and Bt cotton.

Common potassium fertilizers:

• Muriate of Potash (MOP – 60% K)

• Sulphate of Potash (SOP – preferred in sulphur-deficient soils)

Why potassium increases yield:

• Improves boll size and weight

• Enhances fibre strength and length

• Increases resistance to drought and disease

Field insight:
Farmers who apply potassium at flowering and boll development stages report more uniform boll opening and reduced shedding.

                                                

Sulphur: The Missing Link in Many Fields

Sulphur deficiency is widespread due to reduced use of organic manures and SSP.

Sulphur sources for cotton:

• SSP

• Ammonium sulphate

• Gypsum

• Elemental sulphur (where recommended)

Benefits:

• Improves nitrogen efficiency

• Enhances oil content in cottonseed

• Supports chlorophyll formation

Why it matters now:
Soil surveys in Maharashtra, Telangana, and Gujarat increasingly show sulphur-deficient cotton fields, making sulphur application a yield booster rather than an optional input.

Micronutrients: Small Doses, Big Yield Impact

While required in small quantities, micronutrients can significantly influence cotton yield.

Key micronutrients for cotton:

• Zinc (Zn)

• Boron (B)

• Magnesium (Mg)

Application methods:

• Soil application (zinc sulphate)

• Foliar sprays at flowering and boll formation

Yield response observed:

• Reduced flower and boll drop

• Improved pollination

• Better fibre uniformity

Agriculture universities now recommend at least one foliar micronutrient spray in high-yield cotton systems.

Integrated Fertilizer Strategy Works Best

There is no single “best fertilizer” for cotton yield. Yield increases come from balanced nutrition, not isolated inputs.

A practical fertilizer approach includes:

• Soil testing before sowing

• Basal dose of N, P, and K

• Split nitrogen application

• Potassium at reproductive stages

• Sulphur and micronutrients as per deficiency

Farmers combining chemical fertilizers with organic inputs (FYM, compost, biofertilizers) are also seeing improved soil health and more stable yields over time.

Conclusion: Balanced Nutrition, Not More Fertilizer, Raises Yield

Cotton yield increases are no longer about applying more fertilizer, but about applying the right nutrients at the right stage. Nitrogen supports growth, phosphorus strengthens roots, potassium builds bolls, sulphur improves efficiency, and micronutrients fine-tune performance. Farmers who align fertilizer use with soil health and crop stage are consistently achieving higher yields, better fibre quality, and lower input waste. As input prices rise, precision nutrition is no longer optional—it is essential for profitable cotton farming.