Optimization of sprinkler irrigation scheduling scenarios for reducing irrigation energy consumption

In recent years, traditional sprinkler irrigation scheduling scenarios have no longer been applicable to modern agriculture because of the increase in energy prices and the rapid development of smart agriculture. This paper proposes a new irrigation scheduling scenario in which a sprinkler is used as the minimum optimization unit for sectoring design. The main challenge of the proposed approach lies in obtaining the most energy-efficient sectoring and pump operating frequencies, and the high complexity of the optimization problem requires considerable computational effort. To compare the irrigation performance before and after optimization, seven scheduling scenarios are established to analyse the performance of the unified control method, branch scheduling method and sprinkler scheduling method. Through numerical calculations and experimental verification, it was found that sprinkler scheduling can not only meet the pressure requirements of sprinklers without using pressure-regulating valves but also minimize energy consumption. Compared with optimal branch pipe scheduling, optimal sprinkler scheduling can reduce the sprinkler pressure variance from 792 to 180 kPa2 and reduce the irrigation cost by approximately 18%. In addition, by analysing the uniformity coefficient and distribution uniformity under different scenarios, it was found that sprinkler scheduling optimization does not substantially improve irrigation uniformity.