Finding the most efficient and sustainable solution to irrigating crops is more complicated than most people think.
As Bachelor of Science (Honours) student Samantha Conner’s [pictured] project examining the irrigation of almond groves shows, there are many, sometimes conflicting, factors that farmers have to consider when deciding how best to water their crops.
“Drip irrigation might deliver water exactly where it’s needed, but it has several disadvantages,” Ms Conner said.
“As far as almond trees are concerned, it produces weaker trees and can allow water to penetrate the soil before the trees can use it,” she said.
“Sprinkler irrigation, however, produces stronger, more stable trees but allows more water to be lost to evaporation.”
Add to these quandaries the need to occasionally leach the soil with water to prevent the accumulation of salt, and harvesting methods that limit measures to control evaporation, and the irrigator’s plight becomes apparent.
Ms Conner, with her supervisor Flinders University meteorologist Dr Cäcilia Ewenz and colleagues from the South Australian Research and Development Institute, has completed phase one of her project thanks to a National Program for Sustainable Irrigation scholarship that allowed her to conduct field research at Loxton for six weeks.
“We’ve measured the water lost from almond groves through evaporation from the soil and transpiration from the trees,” Ms Conner said.
“The aim now is to use that data to make irrigation more precise by getting the balance right between tree and atmospheric needs.”