Calculate irrigation water requirement and duration based on soil moisture, crop type, and irrigation efficiency.
Calculate irrigation water requirement and duration based on field area, root zone depth, current and target soil moisture, irrigation method efficiency, and flow rate. Get net water needed, actual water withdrawn, water per hectare, and irrigation time in hours and minutes.
You irrigated your corn field for 4 hours with a 10 m³/hour pump, thinking that was enough. The soil was bone dry at 30 cm depth — you only wetted the top 5 cm. The corn showed drought stress 3 days later, and yield was down 18% at harvest. You needed 12 hours of irrigation, not 4. Always calculate based on root zone depth and moisture deficit, not a fixed time.
Efficient irrigation saves water, energy, and money while maximizing yield.
A: Corn: 500-800 mm per season. Wheat: 400-600 mm. Rice: 800-1200 mm (flooded). Soybean: 400-600 mm. Cotton: 500-700 mm. Vegetables: 300-500 mm. These are total crop water requirements (evapotranspiration). Subtract effective rainfall to get irrigation requirement. Peak demand occurs during reproductive stages (tasseling for corn, flowering for vegetables).
A: Drip irrigation: 85-95% efficiency, best for vegetables, orchards, and row crops. Sprinkler: 75-85% efficiency, good for field crops and uniform areas. Furrow: 55-70% efficiency, low cost but high evaporation and runoff. Flood: 40-60% efficiency, simple but wasteful. Drip saves 30-60% water compared to flood, but has higher upfront cost and requires filtration and maintenance.
A: Early morning (5-8 AM): lowest evaporation, leaves dry by midday, reduces disease. Avoid midday (11 AM-3 PM): 20-30% of sprinkler water evaporates before reaching soil. Evening: acceptable but leaves stay wet overnight, increasing fungal disease risk. For drip irrigation, timing matters less (water goes directly to roots), but early morning is still best for nutrient uptake.