The most significant constraint on agricultural production worldwide is the environment, accounting for roughly 70% of crop losses worldwide. By far the biggest environmental factor is water scarcity, which can represent a formidable challenge to farmers.
Agriculture doesn’t just suffer from water shortages; it also helps create them. It’s the single largest consumer of water in the world, draining as much as 90% of resources in some parched agricultural regions.
That’s led concerned farmers and scientists to develop better methods to monitor soil moisture and optimize irrigation. There’s been a move toward greenhouse growing and hydroponics, which make the most of scarce water resources. Organic farmers find plastic mulch–despite its environmental liabilities–helps contain moisture effectively as well as barring insects from feeding on crops.
While laudable, all these solutions alleviate the symptoms of our water crisis without confronting the root cause: the crops themselves.
As long as we rely on resource-intensive monoculture crops, we’ll always be struggling to manage scarce water. But if we could transition to different crops or engineer varietals of our present staples that don’t require so much irrigation flows, we might be able to resolve this crisis more sustainably.
Shifting crops can be a challenging proposition to farmers, who survive on healthy profit margins and don’t like changing cropping practices if it costs them their bottom line.
So, attention has naturally turned to genetic engineering for drought tolerance.
To understand how scientists develop drought-tolerant strains of cash crops, it helps to know how plants respond to drought conditions.
Think of water like fuel for the work plants use for cellular work. When water inputs trickle out, the plant has to divert fuel to mission-critical operations. That means encoding proteins that do things like shut down stomata on the leaf surface to cut down on water lost by transpiration and send down deeper roots to keep the plant alive.
What genetic engineers do to promote drought resistance is to select for production of and sensitivity to these coding proteins. In essence, scientists want these plants to behave as if conditions are always water-poor, thereby reducing the need for irrigation without impacting yield.
They’ve seen considerable success already. Corn, the most significant crop in the United States, is being modified to survive water-poor conditions. In Africa, maize varieties that can thrive without abundant soil moisture promise to boost harvests 10-34%. While results may not be as dramatic in the Americas, the potential for galvanizing production is there.
Beans, too, are amenable to modification to improve their drought tolerance. In Central America, where beans are a cooking staple, researchers worked hard to develop a bean variety that would grow in increasingly dry (rain every twelve days sometimes) and hot (95 – 97 degrees F in the summer) climates. The CENTA-EAC bean, debuted in drought-ridden places like El Salvador, produced a bumper crop.
Recently, scientists discovered the specific gene that codes for drought tolerance in barley, a relief to beer drinkers concerned about the availability and price of the popular alcoholic beverage.
Water shortages will continue to plague growers worldwide until we get to the roots of the crisis. Developing crops that can survive arid, hot conditions will play a huge role in the future of agriculture.