Water as a managed input
Irrigation timing affects yield, nutrient uptake, and disease. Over-irrigation wastes water, leaches nutrients, and favors root rot. Under-irrigation triggers stress and permanent yield loss at critical growth stages.
Scheduling tools
- Soil moisture sensors — tensiometers or capacitance probes at root zone depth.
- Evapotranspiration (ET) models — replace water lost to crop + soil evaporation using weather data.
- Crop coefficients (Kc) — adjust ET for growth stage (higher Kc at full canopy).
Critical periods
Maize is most sensitive during tasseling and silking. Soybean during pod fill. Small grains during heading. Missing irrigation at these windows disproportionately reduces yield.
System efficiency
Drip irrigation delivers highest efficiency; sprinkler and flood systems lose more to evaporation and runoff. Uniformity testing (catch cans for sprinklers) identifies clogged nozzles and pressure problems.