Whether you think global climate change is a serious concern that warrants an international corrective effort, or you contend it’s all a bunch of hooey dreamed up by Al Gore and a bunch of pointy-headed liberals, the incontrovertible fact is that regional climate changes — both natural and man-caused — are proceeding apace.
As rainfall patterns shift, desertification claims hundreds of thousands of additional acres; as more and more rain forest acres fall to bulldozers, erosion increases and the water cycle from plant transpiration is reduced.
These changes are focusing more attention and research on development of crop plants that can grow and produce acceptable yields with less water.
For too long in this country water has been considered an inexhaustible resource. But as with petroleum, we’re finding that isn’t the case, and we’re beginning to pay the piper in terms of scarcer, more expensive water.
Even in areas where yearly rainfall is traditionally ample, deficits are occurring (much of the Mid-South is 15 inches to 20 inches below normal thus far in 2007), droughts have been increasingly frequent and severe, and water tables have fallen. Major lakes, rivers, and streams, once water rich, have in many cases shrunk to the point that supplies are in a crisis situation for urban and rural uses alike.
The anti-agriculture folks are quick to denounce crop production as a disproportionately large user of water. The USDA says agriculture accounts for 80 percent of the nation’s consumptive water use, and over 90 percent in some western states (where many farmers are finding it more profitable to sell their water to cities than to use it for farming).
Confronted with increasing cost and scarcity, farmers have quickly adapted conservation/recovery practices and irrigation systems that use less water and distribute it more efficiently.
But that can only go so far. Developing crop plants that need less water to produce acceptable yields will be another key to keeping agriculture viable.
As genome projects for major crops provide complete maps of the plants’ chromosomal makeup, gene manipulation techniques become more sophisticated, and plant growth modeling becomes more powerful, scientists foresee crops that not only need less water, but offer tolerance to salt, temperature stresses (both heat and cold), and other environmental factors.
Significant strides are being made. In 2002, Cornell University researchers announced the development of a hardier strain of biotech rice that offers drought resistance and is more adaptable to marginal soils.
Shortly after that, USDA Agricultural Research Service scientists announced two new lines of salt-tolerant plants related to wheat (in the U.S., saline soils reduce crop yields by about 25 percent).
It takes about 125 gallons of water to produce a pound of wheat. Researchers in Egypt have been working toward commercialization of a wheat variety with a barley gene that has enabled them to cut irrigations from eight to only one.
Crops with tolerance to drought and other environmental stresses will enable farmers to not only use less precious water, but also to reduce energy costs associated with pumping.