water / Irrigated-crop managers
Field irrigation scheduling
Build a field-specific routine for deciding when to irrigate using root-zone capacity, crop demand, rainfall, monitoring, and system delivery time.
Define the reservoir
Soil texture, active rooting depth, and available water capacity determine how much plant-available water the managed root zone can hold.
- Identify the main soil management units
- Estimate active rooting depth for the crop and stage
- Use locally appropriate available-water values
Choose a monitoring method
Scheduling requires a repeated estimate of root-zone water status, not a calendar alone.
- Use soil-moisture sensors, field assessment, or a weather-based water balance
- Place sensors or observations where they represent the managed area
- Check often enough to act before unacceptable stress
Set an operating trigger
Irrigation must start early enough that the system finishes before depletion exceeds the chosen management limit.
- Select a locally appropriate allowable depletion threshold
- Account for forecast crop use and the irrigation cycle duration
- Consider credible rainfall without assuming it will occur
Close the loop
Measured delivery, rainfall, runoff, and crop development change the next decision.
- Record actual irrigation and rainfall
- Check whether water reached the intended root zone
- Adjust the balance, sensor interpretation, or system operation after field observation
SAFETY & LOCAL BOUNDARIES
Adapt before acting.
- Crop water needs and allowable depletion are crop-, soil-, climate-, and stage-specific.
- Avoid refilling beyond the effective root zone; excess water can increase leaching risk.
- Inspect system uniformity and verify actual delivery.
Related systems
Connect practice to technology.
Evidence
Primary learning sources.
01Irrigation managementUniversity of Minnesota Extension · Accessed 2026-07-12