California experienced record rainfall in 2017. However, the US state has learned to live with drought and farmers know to plan for potential future shortages. New high-tech approaches to irrigation are playing their part in meeting this challenge.
As part of our series on the changing face of water use in global agriculture, we find out more about developments in irrigation on California’s farms. We caught up with Mike Wade, Executive Director of the California Farm Water Coalition, which raises awareness of water-related issues in agriculture.
What irrigation techniques are Californian farmers using to try to make best use of water?
Mike Wade: “Californian agriculture has used about the same amount of water for the last 50 years. But our crop production has increased 43%. That’s attributable to higher-efficiency irrigation, better management practices, and better crop types.
“It can cost as much as $1,200-1,500 per acre to put in a high-efficiency irrigation system, which meant farmers couldn’t previously afford to irrigate lower-value annual crops with it. However, thanks to GPS, we can now put in sub-surface drip irrigation systems. By using GPS-controlled tractors and planters, farmers can invest in these systems for annual crops like tomatoes, melons and corn. Previously, there was a high risk that these were ripped out accidentally because there’s no tractor driver who can drive straight enough to avoid hitting buried irrigation lines.”
Uniform irrigation: uniform crops
What exactly does high-efficiency irrigation involve?
“Instead of the old type of furrow, with a crop of melons or tomatoes or whatever planted on a bed and water being run in the furrow beside it, the new systems have buried tubes with small emitters on them that provide the same amount of water at every location around the field. So you get uniform crop production. You’re also able to reduce the amount of pesticide applications and cultivation activities across the field because the weed seeds on the surface that would otherwise sprout simply don’t do that now.
“People often think that high-efficiency irrigation means less water being used to grow a crop, but in many cases it’s the same amount of water or even more water because it’s meeting higher water demands by a more vigorous plant. That’s where we see higher production, higher-quality crops and more return on investment for the farmer.”
“High-efficiency irrigation doesn’t always mean less water”- Mike Wade, California Farm Water Coalition
You mentioned GPS, are there other technological enhancements we can expect to see in fields in coming years?
“In terms of looking forward, we’re seeing more automation and irrigation systems that are run at the district level rather than on individual farms. Thanks to computer technology, solar-powered controls and automated gate structures on canals, activities can occur from a central location, or they can be automated which also helps improve efficiency.”
Can we envisage these technologies becoming less expensive and more widely available, for instance in the Global South?
“I think it has to change, we have to find a way to feed the growing world population. Going from the traditional flood irrigation model with canals and diversions from rivers to energy-powered drip and micro-irrigation systems takes a big investment, but I think it can play out in other parts of the world and probably will need to.”