Precision Irrigation Mapping
Definition
Precision irrigation mapping integrates soil properties, crop water demand, weather forecasts, and sensor feedback to prescribe variable-rate irrigation across fields. Geospatial layers include soil texture, electrical conductivity, elevation-derived water accumulation, NDVI/EVI time series, canopy temperature, and evapotranspiration estimates. Maps translate these inputs into zones or continuous rates for pivots and drip systems. Feedback loops compare yield monitors and soil-moisture probes to prescriptions, improving models over seasons. The goal is to save water and energy, increase yield quality, and reduce nutrient leaching. Practical constraints—pump capacity, pressure drops, and hardware sections—shape implementable maps, not just agronomic ideals.
Application
Growers schedule irrigations by zone; cooperatives benchmark water productivity; lenders and insurers validate climate-smart investments; regulators monitor water use efficiency. Extension agents use maps to teach deficit irrigation strategies under drought.
FAQ
Which indices best indicate stress?
Thermal-based crop water stress index and NDVI/EVI trends together; thermal responds quickly to stress, spectral tracks biomass over time.
How are prescriptions delivered to hardware?
Export as shapefiles/GeoJSON or controller-native formats with flow rates by zone; test in small blocks before full-field deployment.
Can variable-rate pay off for small farms?
Yes if variability is high; start with simple two or three zones and low-cost sensors. Savings often justify incremental upgrades.
How to validate savings?
Compare water meters and yield across seasons with and without prescriptions; control for weather to estimate true gains.