New laser-beam technology could revolutionize the irrigation of crops in San Diego and beyond, according to a group of students at the Jacobs School of Engineering.
The research team led by assistant professor of environmental engineering Jan Kleissl is using a large aperture scintillometer to measure the amount of water that crops lose to evaporation and the peak hours at which this loss occurs.
Many recent irrigation advancements have addressed systems of water delivery, such as sprinklers, but Kleissl said state droughts have created a demand for more sophisticated methods of water conservation.
The goal is to give farmers an accurate reading of how efficiently their crops use water, more so than any current technology provides.
‘What’s new about our approach is the monitoring side of it,’ Kleissl said. ‘We’re trying to improve on that.’
The scintillometer that Kleissl’s team is using focuses laser beams across a field and records changes in the air’s refractive index caused by fluctuations in temperature and humidity.
Farmers can use this data to decrease irrigation during hours of high water loss.
Researchers placed the device on half of a UC-operated experimental alfalfa farm roughly a half-mile long and a quarter-mile wide to study the area for at least two years. The other half of the farm will be irrigated conventionally.
In addition to being especially thirsty, alfalfa is the most common crop in the Imperial Valley, where the average annual rainfall is fewer than three inches and temperatures often exceed 100 degrees Fahrenheit for several months of the year.
If the tests show substantial water savings, Kleissl hopes to see scintillometers placed on farms across the state.