Turn garden measurements into practical watering decisions today. See buffer days and liters per cycle. Save time, reduce runoff, and keep beds evenly moist.
| Soil type | Typical AWC (mm/m) | Suggested p | Notes |
|---|---|---|---|
| Sandy | 40–80 | 0.30–0.40 | Low storage, frequent watering, fast drainage. |
| Loam | 90–140 | 0.45–0.55 | Balanced storage and aeration for many crops. |
| Clay | 140–220 | 0.35–0.50 | High storage, but slower infiltration and aeration. |
| Raised mix | 70–130 | 0.40–0.55 | Varies with compost, coir, bark, and sand content. |
Water buffering describes how long your root zone can supply moisture before stress begins. A longer buffer reduces emergency watering and improves nutrient uptake. It also helps salts dilute between irrigations and keeps microbes active in warm weather.
Total available water depends on available water capacity and effective root depth. Sandy soils store less per meter, while loams and clays store more. Raised mixes vary with compost, coir, bark, and sand content. Deeper rooting increases storage, but only if the soil is aerated, not compacted, and roots can penetrate.
Daily use is estimated from reference evapotranspiration, then scaled by crop coefficient and a microclimate factor. Leafy greens typically use less than fruiting crops at peak canopy. Mulch lowers soil evaporation and reduces crusting, often cutting demand by 10 to 50 percent. Shade cloth, windbreaks, row cover, and bed orientation can further shift microclimate and reduce midday losses.
Not all rainfall becomes plant-available. Effectiveness accounts for runoff, canopy interception, and infiltration limits, so a storm may contribute less than its total depth. Light rain after dry soil can be less effective than steady soaking. Irrigation efficiency converts net soil need into applied water, reflecting losses from evaporation, drift, leaks, and uneven distribution. Improving uniformity can reduce total liters without changing plant health.
Buffer days indicate a practical interval between irrigations at your chosen depletion fraction. Use gross liters per event to set timer runtimes, then verify with a soil probe or finger test at the target depth. If buffer days are short, increase mulch, add organic matter, correct compaction, reduce irrigated area, or lower the depletion fraction for sensitive crops. Recalculate when weather shifts or plants grow. Track actual run time, emitter flow, and wetting pattern, and adjust the effective area so calculated volumes match what your system truly wets. Record adjustments in notes.
It is the estimated number of days your root zone can meet plant demand before reaching your chosen depletion level, based on ET0, crop coefficient, mulch, and soil storage.
Start with the preset that matches your texture, then refine using a soil test, feel method, or local extension guidance. AWC rises with organic matter and falls with coarse sand.
Efficiency converts the soil’s net water requirement into the applied amount. Losses from evaporation, runoff, leaks, or uneven coverage increase the gross liters you must deliver.
Yes. Mulch reduces soil evaporation and moderates surface temperature. In many beds it meaningfully lowers daily water use, extending buffer days and reducing liters per irrigation event.
Enter total expected rain for the interval and estimate effectiveness. Short intense storms may run off or bypass roots, while steady rain often infiltrates better and contributes more to storage.
Use the wetted area, not the full bed area. Alternatively, keep area as-is and lower efficiency or microclimate factor to reflect partial wetting, then verify with a probe.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.