🌱 NPK Fertilizer Calculator

Calculate exact N-P-K needs for your crop and field size

Nitrogen (N) Required
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Phosphorus (P₂O₅)
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Potassium (K₂O)
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NPK Fertilizer Calculator for Indian Crops

Applying the right quantities of Nitrogen (N), Phosphorus (P), and Potassium (K) is the foundation of productive farming. Under-application causes poor yields; over-application wastes money, harms soil health, and contributes to groundwater pollution. This calculator uses ICAR (Indian Council of Agricultural Research) recommendations adjusted for field area and soil fertility level.

What N, P, K Each Do

Nitrogen (N) drives vegetative growth — leaf and stem development. Applied primarily through Urea (46% N) or DAP. Nitrogen-deficient crops show yellowing of older leaves first. Phosphorus (P₂O₅) supports root development, flower formation, and seed production — critical in early growth stages. Applied through DAP or SSP. Potassium (K₂O) strengthens cell walls, improves disease resistance, and enhances fruit/grain quality. Applied through Muriate of Potash (MOP).

Why Soil Fertility Level Matters

Low-fertility soils require higher doses to achieve target yields; already-fertile soils need less additional input. Ideally, get a soil test done every 3 years from your local Krishi Vigyan Kendra (KVK) or state agriculture department lab for precise recommendations specific to your field's actual nutrient levels.

Frequently Asked Questions

How do I convert NPK to actual fertilizer bags? +
Urea (46% N): divide N requirement by 0.46. DAP (18% N, 46% P₂O₅): divide P requirement by 0.46. MOP (60% K₂O): divide K requirement by 0.60. One standard bag is 50kg — divide your calculated kg by 50 to get number of bags.
When should nitrogen be split-applied? +
Split nitrogen into basal (at sowing) and top-dressing (30-40 days after sowing) for most crops. Rice and sugarcane may need 3 splits. This reduces leaching losses and improves nitrogen use efficiency.
Is this calculator suitable for organic farming? +
No — these recommendations are for conventional chemical fertilizers. Organic nutrient sources (FYM, compost, green manure) have different nutrient contents and release rates; consult your KVK for organic-specific guidance.