We recommend management of irrigation using ET data, and using soil moisture as confidence feedback.
100% ET means that you replace the exact amount of water that was lost the day before via plant transpiration and soil evaporation.
In that case the soil moisture remains at the same level for a longer period. By checking the soil moisture trend, you can estimate if you are irrigating too much, too little or the same amount as the plants water usage.
Soil water potential is measured in kilopascal (kPa) or centibar (cb), both giving the same numbers (10 kPa = 10 cb)
0 -10 means abundance of water, more water than the soil can typically hold.
10 - 50 is a good range for most crops
> 50 is a range where plants start to observe water stress, and with increasing dryness eventually reach permanent wilting point where damage is irreversible.
Below example shows data from a field that was irrigated less than 100%, and a steady climb of dryness level. For an over-irrigation situation, you would see the opposite with sensor readings declining.
For easy interpretation of the chart, we provide a color code background. The green zone indicates the recommended levels for most crops.
Please check with your agriculture consultant for the recommended limits that apply to your crop for best results.