🌾 Crop Yield Estimator — Tonnes per Hectare Predict your crop yield based on growing season rainfall, plant population, and stress factors. Works for wheat, barley, canola, and other broadacre crops.
Quick answer: Water-limited yield = (Rainfall × Rain Use Efficiency) ÷ 1000. Wheat on 250mm rain with RUE 18 = 4.5 t/ha. Final yield = water-limited × stress factors (frost, heat, nutrients).
🌾 Estimate Crop Yield
Crop Type Wheat (RUE: 15-20 kg/mm/ha) Barley (RUE: 16-22 kg/mm/ha) Canola (RUE: 10-15 kg/mm/ha) Oats (RUE: 12-18 kg/mm/ha) Triticale (RUE: 15-20 kg/mm/ha)
Estimate Yield
📐 How Crop Yield Is Estimated Water-limited yield (kg/ha) = Rainfall (mm) × Rain Use Efficiency (kg/mm/ha)
Measure growing season rainfall — April-October for winter cropsApply rain use efficiency — crop-specific potential yield per mm rainApply stress factors — frost, heat, disease, nutrient stress reduce yieldConvert to tonnes — divide kg/ha by 1000📊 Worked Example Wheat crop with 250mm growing season rain, RUE 18 kg/mm/ha, 15% stress from frost.
Water-limited = 250 × 18 = 4,500 kg/ha (4.5 t/ha)
Without frost stress, yield would have been 4.5 t/ha. Frost cost the grower 0.7 t/ha — at $300/t = $210/ha loss.
❓ Frequently Asked Questions
How do you estimate crop yield? Water-limited yield = (Growing season rainfall × Rain use efficiency) ÷ 1000. Example: 250mm rain × 18 kg/mm = 4.5 t/ha. Multiply by stress factors for actual yield.
What is rain use efficiency for different crops? Wheat: 15-20, Barley: 16-22, Canola: 10-15, Oats: 12-18, Triticale: 15-20 kg/mm/ha.
How do I measure crop yield in the field? Use a 1m² quadrat. Count heads × grains per head × grain weight. Example: 500 heads/m² × 25 grains × 40mg = 500g/m² = 5 t/ha. Take 10 random samples.
What factors reduce crop yield? Frost during flowering (can halve yield), heat stress (above 35°C), waterlogging, nutrient deficiency, weeds, disease, and poor establishment.