There is moisture within ~3m in even the driest deserts. The water in the box slowly releases to make a connection with the capillary water deep below for the r

There is moisture within ~3m in even the driest deserts. The water in the box slowly releases to make a connection with the capillary water deep below for the roots to reach within the first year. It's a planting method, not irrigation. Refills during rains, prevents evaporation via a clever siphon.