On the basis of some registered information in three areas from Moldova, it was calculated the energy balance and the energetically efficiency of the applied irrigation on eight species of plants. The information's obtained proved that the irrigation process is efficient from the energetically point of view for all the field crops which have been seen in south droughty zone and this process is less efficient in central and moderate warm and moist zone. In the cool moist zone from northern, the irrigation process is efficient only in a few cultures. On the slope lands, where the cultures need more water, the energetically efficiency of the irrigation process is greater than on a plat field. The greatest values of the balance and energetically efficiency were obtained in sugar beet, followed by alfalfa, maize for grain or silage, potato, wheat and sunflower, on the last places coming soybean and bean. There reacted favourable to irrigation the sugar beet, followed by maize for grain or silage, sunflower, potato and wheat, in bean and soybean being registered an energy balance very reduced.