An automatic irrigation system having a simplified structure can
intermittently supply water (and liquid fertilizer) required by farmer
products under water saving conditions depending on the weather condition
of the day independent of the size of an irrigation area. Water from a
water source is pumped by a motor pump driven with electric power
generated by a solar panel and stored in a storage tank. When a
predetermined amount of water is stored in the tank, a water draining
device continuously drains the stored water. This cycle is repeated in
proportion to an amount of solar radiation incident on the solar panel.
The water is then guided to the irrigation area with a tube irrigation
system.