NPK Ratio: The ratio of Nitrogen (N), Phosphorus (P), and Potassium (K) in soil or fertilizer. These are the three macronutrients essential for plant survival and growth.
Monitoring NPK is critical. If smart farming systems detect that water content is too high, there is a risk of NPK leaching away from the root zone, effectively throwing expensive fertilizer down the drain.
NPK stands for nitrogen (N), phosphorus (P) and potassium (K) — the three macronutrients that drive plant growth. A fertiliser labelled 10-26-26 contains 10% N, 26% P2O5 and 26% K2O by weight. Recommended NPK ratios differ by crop and growth stage: nitrogen drives leaf growth early, phosphorus supports root and flower development, potassium governs water regulation and grain/fruit quality.
Indian soils show chronic imbalance — decades of urea-heavy application have skewed N:P:K usage far from the recommended balance, degrading soil health and yield response. Matching application to actual soil status, rather than habit, is one of the highest-return corrections available to a farm.
VarshaKrishi crop guides list recommended NPK ratios per crop, and the sensor platform tracks nutrient depletion patterns across the season so top-dressing decisions follow measured demand. Each crop guide on this site lists its specific ratio.
For field recommendations, 120:60:40 means the crop needs 120 kg of nitrogen, 60 kg of phosphorus (as P2O5) and 40 kg of potassium (as K2O) per hectare per season — usually split across basal and top-dressing applications timed to growth stages.
Excess nitrogen produces lush, soft vegetative growth that lodges easily and attracts pests, delays maturity, leaches into groundwater, and wastes money. Sensor-informed split applications match nitrogen supply to actual crop demand.
See also: Precision Agriculture, Capacitive Soil Sensor — or browse the full smart farming glossary.
Discover how VarshaKrishi utilizes this technology in our offline-first systems across rural India.
Read our Ultimate Guide to Smart Farming