Nitrogen Rate Calculator — Wheat, Sunflower, Maize, Rapeseed (Ukraine)

How the calculation works

The calculator uses the standard nitrogen nutrition balance recommended by the Ukrainian Ministry of Agrarian Policy and NUBiP. Formula: total nitrogen demand = target yield × N uptake per tonne of product. Subtract nitrogen applied in autumn and residual soil N (from a soil test or the typical 15 kg/ha). The remainder is the spring top-dressing, split into two passes: 60% at early vegetation re-growth, 40% at the tillering-to-stem-elongation stage. Final step: convert the active ingredient into physical mass of the chosen fertilizer using its N percentage — UAN-32 contains 32%, ammonium nitrate N33 contains 33%, urea contains 46%. For Polissia the rate is automatically raised to account for higher losses on sandy soils.

1. 1

   Pick the crop

   Winter wheat, sunflower, maize, or rapeseed. Each crop has its own N uptake coefficient per tonne of product.

2. 2

   Enter target yield

   A realistic target yield in t/ha. Typical winter wheat targets: 5–7 t/ha in Forest-Steppe, 4–5 t/ha in Steppe, 3–4 t/ha in Polissia.

3. 3

   Pick the agro-zone

   Steppe / Forest-Steppe / Polissia. Polissia auto-increases the rate by 10–15% because of higher losses on sandy soils.

4. 4

   Subtract autumn N and residual soil N

   If you applied N in autumn (e.g., through NPK compounds), enter the value. If you have a soil test, enter residual N; otherwise use the typical 15 kg/ha.

5. 5

   Pick the nitrogen fertilizer

   UAN-32 (32% N), ammonium nitrate N33 (33% N), or urea (46% N). The calculator converts the active ingredient into physical mass.

6. 6

   Read the result

   The result shows: total N demand, spring top-dressing, first pass (60%), second pass (40%), and the physical mass of the chosen fertilizer. Toggle "Explain the math" to see the formula.