PISA-CA is a collaborative research project in active development at UC Davis and ARO-Volcani.
It provides estimates based on satellite remote sensing and scientific models.
Results are not certified irrigation recommendations and may differ
from conditions in your specific field.
Supported climates: Mediterranean, semi-arid, temperate, and arid regions
in both hemispheres. Monsoon and equatorial climates are outside calibration
and will show a warning.
Supported species: Almond, Pistachio, Walnut, and a configurable
"Other" option for any temperate deciduous crop.
Calibrated for orchards 4+ years old.
Young orchards (1–3 years) have sparse canopy and shallow roots —
this tool may overestimate their water needs.
By using this tool you accept full responsibility for any irrigation decisions made.
For questions, or to participate in the research project, contact:
Click your orchard on the map (or use "Navigate to Region" to jump to your area first). Hemisphere, rainfall source, and units are automatically detected from the location.
Select your species — Almond, Pistachio, Walnut, or Other. Each species has different canopy timing. Choose "Other" to set bloom and senescence months manually for any deciduous crop.
Click "Get Water Budget." The tool downloads satellite data — rainfall, evaporation demand, canopy size (NDVI), soil water-holding capacity, and climate zone.
Set your irrigation season using the sliders. The tool calculates how much water your trees need each month.
Review Winter Irrigation. The tool recommends how much to apply before the season to fill the soil. Adjust if you applied more or less.
Optional: Set rooting depth. Override the automatic soil depth if you know your orchard's root zone (e.g. 80 cm for shallow soils). Leave at "Auto" to use satellite-based estimation.
Optional: Pre-harvest dry-down. Enable this to stop irrigation before harvest. Set the start date and duration — the saved water is redistributed to the rest of the season.
Read the chart. The chart shows the full water year: blue-shaded dormancy months (rain recharge) and yellow-shaded active season. Green bars = rain, blue bars = irrigation, gold line = crop water demand (ETc), green line = soil water reserve.
Adjust sliders to explore what-if scenarios — the chart updates instantly.
Sprinkler Operating Schedule
After getting your water budget, configure your Sprinkler Settings in the left panel:
Output rate — how much water your sprinklers deliver per hour (e.g. 0.04 in/hr)
Block duration — minimum run time per irrigation set (e.g. 6 hours)
The tool converts monthly water amounts into a weekly sprinkler schedule showing exactly how many hours to run each week.
References:
Sperling O, Tricerri N, Orozco J, Ellis Z, Gardi I, Secchi F, Zwieniecki MA (2025) Integration of seasonal rainfall and irrigation into a water management plan for almond orchards. Agric. Water Manag. 319:109743
Sinclair TR, Holbrook NM, Zwieniecki MA (2005) Daily transpiration rates of woody species on drying soil. Tree Physiology 25:1469–1472