The decision variable is the required irrigation water quantity Qd(i), in the observed period (stage) i, which is also the mean daily value of water quantity at the output of the PV pumping system. State variables are soil moisture W(i) (total water quantities in soil of an area of location +A+) that depend on the decision variable, state of the system in the previous stage and state, of the surroundings. Natural variables are effective precipitation R(i),actual evapotranspiration ETr(i), and infiltration INF(i).