Dry Farming Isn't A Solution To The Drought
Photo:tumblingrun/Flickr/Creative Commons License
As the state's drought continues to worsen and worsen -- we're just about to enter the official dry season, which shows no signs of abatement until the possible fall landing of El Niño, which even then won't help that much -- the time has come for California farmers to start pulling out every trick they have in order to continue growing the nation's food. One of the tricks that's being proposed is a return to dry farming, a method in which farmers grow crops without irrigation.
It's a ray of hope in an otherwise bleak future, one pointed to as a temporary solution until the rains come back. Unfortunately, it's probably not going to work.
First, perhaps it's best to explain how dry farming works. Essentially, it's taking soil that's been soaking during the rainy season, using a roller to compact the top of the soil into a dry crust that locks the moisture inside (almost like a vacuum seal to keep the liquid from evaporating inside), and then using the moisture in that soil to provide water for plants. It's an ancient technique that's popular in dryer regions of the world like the Mediterranean, and was used in the pre-irrigated American West before dams and aquifers made the process unnecessary.
The reason it was/is so popular has to do with the amount of water needed to produce crops. Rather than constantly irrigating through the year, dry farming needs as little as nine inches of precipitation a year to provide enough water for crops. (To give you some sense of how small this amount is: Los Angeles, certainly not the most fertile place in the state, gets roughly 15.05 inches of rainfall a year.) It makes sense why this technique is being dusted off while we're in the midst of drought, but some farmers have been utilizing it over the years for another reason entirely.
See, without water in the way, fruits that are grown using dry farming methods end up with a greater density of sugars and "flavor compounds." Many winemakers and artisanal fruit growers use dry farming methods to give their products a more potent punch, leading them to become a more desirable commodity in the marketplace:
"Once you taste a dry-farmed tomato, you'll never want anything else," she says, adding that she could be selling hundreds of 14-pound cases per day if her 10-acre tomato field could meet the demand.
And therein lies the rub, and ultimately why it isn't going to save us from the drought. While a possible solution to keep the crops growing on small farms, dry farming doesn't work on a large scale:
In place of huge yields and produce (fruit and vegetables may grow twice the size of their dry-land counterparts), farmers get smaller, hardier crops with several times the flavor (the water stress concentrates sugars and nutrients), but the yield penalty in bad years is steep: 12 tons per acre for apples, compared to 30 to 40 tons produced by large apple farms in the Central Valley.
(Not to mention, another possible side effect of trying to perform dry farming on a massive scale: The possibility of causing another Dust Bowl.)
When we talk about how the California drought is affecting our food, we're not talking about small mom-and-pop farms growing their fruits and veggies for sale at local farmers' markets. We're talking about how the state feeds the entire country. More than 230 crops are grown in California's Central Valley, including half of the country's nuts, fruits, and veggies. (Ninety percent of the world's almond supply is also grown here.) Those kinds of numbers don't afford solutions where large yields are traded in for more flavorful products. Dry farming is, unfortunately, a non-starter for most of the farms affected by the drought.
That's not to say dry farming shouldn't enter the conversation. If smaller farms were to forgo their current irrigation techniques, it certainly would lower the amount of water being used, ever so slightly. But dry farming on a large scale in order to counter the drought? That's a fantasy.