Modern agricultural irrigation systems pump hundreds or thousands of gallons of water per minute. They do this for hundreds or thousands of hours per year. Ideal systems would pump the minimum necessary amount of water at the minimum necessary flow rate over the greatest number of hours per year in order to optimize both water and energy use. However, typically, farmers rely on manual operation of the pump equipment based on physical, in person, inspection of their field and using learned experience. They do this because growing crops is high-stakes business and experimentation comes with a lot of risk. Unfortunately, risk-avoidance leads to greater pumping and more run-off, more pump usage, and more energy usage than is necessary to do the job.
What does optimization look like? Variable frequency drive (VFD) controlled electric motors installed on properly designed irrigation system that respond to moisture sensors embedded in the soil.