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    Calculateur d'engrais gratuit

    Calculateur d'engrais (N-P-K)

    Calculez la quantité d'azote, de phosphate (P₂O₅) et de potasse (K₂O) dont votre culture a besoin — par hectare et au total du champ. Basé sur les tables d'exportation d'éléments nutritifs IPNI + FAO. Gratuit, sans inscription.

    Rendement typique pour Maïs : 8–12 t/ha

    Résultats d'analyse de sol (facultatif — réduit le besoin en engrais)

    À partir d'une analyse de sol standard. Laissez vide pour une recommandation prudente du pire cas (suppose un apport du sol nul).

    Prix des engrais (facultatif — ajoute une estimation de coût)

    How Fertilizer Calculations Work

    Fertilizer planning starts with a simple equation: nutrient demand = yield × removal rate. Each crop pulls a predictable amount of nitrogen, phosphorus, and potassium out of the soil per ton harvested — documented in the IPNI Crop Nutrient Removal Tables and FAO fertilizer bulletins. Subtract what your soil already provides (from a soil test), add a small buffer for losses, and you have a rational fertilizer rate.

    Why Removal Rates Differ by Crop

    • Grain legumes (soybean, lentil): exceptionally high N removal (~65 kg/ton) because the grain is protein-rich. Much of this comes from nitrogen fixation, so N fertilizer requirement is often near zero for inoculated crops.
    • Tuber / fruit crops (potato, tomato): low N but high K removal, reflecting the fruit or tuber storage tissue.
    • Cotton: the highest removal per ton because lint plus seed both export nutrients; K₂O removal (~45 kg/ton lint) is the standout.
    • Cereals (corn, wheat, rice): N is the largest need; P and K are modest. Residue retention (straw) vs removal significantly changes K balance.

    Beyond the Calculator

    Real fertilizer decisions depend on more than removal. Soil pH affects nutrient availability — phosphorus is locked out below pH 5.5 and above 7.5. Cation exchange capacity (CEC) determines how much K the soil can hold without leaching. Variable-rate technology (VRT) applies different rates in different zones of the same field based on satellite NDVI or soil-sampling grids, typically cutting total fertilizer use 10-25% without yield loss.

    For field-specific recommendations that combine soil tests, satellite imagery, and your real-time weather, see WiseYield's farm budgeting + AI recommendation suite or read our glossary entries on NPK, variable rate application, and foliar feeding.

    Want AI-Driven Variable-Rate Recommendations?

    WiseYield combines soil tests, satellite NDVI, weather, and your field history to recommend zone-specific fertilizer rates — typically cutting input costs 10-25% without yield loss.

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