Crop Nutrient Removal Calculator & What Your Harvest Takes
Budgets nutrients for wheat
See how much N, P₂O₅ and K₂O your harvest exports from the soil — per tonne and over your whole area — plus the urea, DAP and MOP needed to replace it and keep fertility steady.
Removes 22-11-6 kg N-P₂O₅-K₂O per tonne of produce.
Harvesting 2 tonnes of wheat (grain) exports about 44 kg N, 22 kg P₂O₅ and 12 kg K₂O from your soil. To replace it you'd need roughly 77 kg urea, 48 kg DAP and 20 kg MOP.
Next: if you remove the residue (straw/stover) too, potassium removal rises sharply — return residues or factor extra K. Use this as a maintenance baseline alongside a soil test and the Fertilizer (NPK) calculator.
Removal coefficients are typical (ICAR/IPNI) for economic yield; residue removal and variety shift the actual figures.
Nutrient removal — key facts
- Removed
- rate (kg/t) × yield (t)
- Wheat grain
- ≈ 22-11-6 kg N-P-K /t
- Rice grain
- ≈ 20-9-6 /t
- Soybean seed
- ≈ 65 kg N /t
- Residue (straw)
- holds most of the K
- Replace with
- urea + DAP + MOP
- Use as
- maintenance baseline
- Privacy
- Runs in your browser; nothing uploaded
Don't mine your soil — replace what you remove
Every harvest is a withdrawal from the soil's nutrient bank: the grain, tubers or fruit you cart off carry away nitrogen, phosphate and potash that the crop pulled from the ground. Keep withdrawing without depositing and yields drift down as the soil runs lean. This tool multiplies a crop's removal rate (kilograms per tonne of produce) by your yield and area to show the total exported, then translates it into the urea, DAP and MOP you'd need to put it back.
Treat the result as a maintenance floor — the minimum to hold fertility level — not the full fertilizer recommendation, which also weighs what the soil supplies, losses, and your target yield. Two things shift removal sharply: residues (baling straw can double potassium loss, so return them where you can) and crop type (legumes export a lot of nitrogen in protein-rich seed). Pair this with a soil test and the Fertilizer (NPK) Calculator for the actual dose.
Budget your nutrients
See the N-P-K each harvest exports so you can plan to put it back.
Get a maintenance dose
Turn removal into urea/DAP/MOP as a baseline to keep fertility stable.
Value your residues
Understand how much potash you'd lose by removing straw versus returning it.
Compare crops
See which crops in a rotation are heaviest on N, P or K.
Frequently Asked Questions
What is crop nutrient removal?+
It's the amount of nitrogen (N), phosphate (P₂O₅) and potash (K₂O) carried off the field in the harvested produce. Every crop removes a characteristic amount per tonne of yield — for example wheat grain removes roughly 22 kg N, 11 kg P₂O₅ and 6 kg K₂O per tonne. This tool totals it for your yield and area.
Why does nutrient removal matter?+
Nutrients leave the field in the harvest, so soils slowly run down unless what's removed is replaced. Knowing the removal gives you a maintenance baseline — the minimum to put back to keep fertility stable — which you adjust up or down from a soil test.
How much NPK does my harvest remove?+
Multiply the crop's removal rate (kg per tonne) by your total yield (tonnes). A 2 t/acre wheat crop on 1 acre removes about 44 kg N, 22 kg P₂O₅ and 12 kg K₂O. The tool does it and also converts the figures into bags of urea, DAP and MOP to replace them.
Does removing the straw or residue change it?+
Greatly — for cereals, most of the potassium (and a lot of the nitrogen) is in the straw/stover, not the grain. If you bale and remove residues, K removal can more than double. Return residues where you can, or budget the extra potash; this tool uses economic-yield (grain/produce) coefficients.
How do I replace the removed nutrients?+
Convert the removed N-P₂O₅-K₂O into fertilizer: DAP supplies phosphate (and some N), MOP supplies potash, and urea tops up the remaining nitrogen. The tool shows approximate kilograms of each — refine the dose with the Fertilizer (NPK) Calculator and a soil test.
Which crops remove the most nutrients?+
High-protein and high-yield crops remove the most: legumes like soybean remove large amounts of nitrogen (in the seed), while high-tonnage crops like sugarcane and bananas remove a lot of potassium overall. Per tonne, oilseeds and pulses are nutrient-dense; per acre, high-yield cereals add up.
Is removal the same as the fertilizer dose?+
No. Removal is what leaves in the harvest; the fertilizer dose also accounts for what the soil already supplies, losses (leaching, fixation, volatilisation) and a target yield. Removal is a useful maintenance floor, not the full recommendation — use it alongside a soil test.
What about nutrients other than NPK?+
Crops also remove secondary nutrients (sulphur, calcium, magnesium) and micronutrients (zinc, boron, iron). NPK dominates the budget and is what this tool covers; watch for sulphur and zinc especially in oilseeds, pulses and intensive systems.
Does this account for nutrients the soil supplies?+
No — it's a removal (export) figure, not a net balance. The soil and organic matter supply a share of the crop's needs, so you don't always have to replace 100% with fertilizer. Combine removal with a soil test to set the actual replacement.
How accurate are the removal figures?+
They're typical published values (ICAR/IPNI/FAO) for economic yield and vary with variety, grain quality and whether residues are removed. Treat them as a solid planning baseline and refine with local data or tissue/grain analysis where precision matters.