Each crop has different water needs. Additionally, these needs change during the growing season. In some phenophases it is extremely important for the crop quality and yield, that a plant gets enough water. In others, it is beneficial that it gets enough - but not too much - to insure optimal quality, storage capacity and taste of produce.
You can learn to correctly identify phenophases of individual crops and update this information regularly in the system. This information, together with the soil measurements, soil composition and the weather forecast will be used to calculate the crop's irrigation needs.