Ninety percent of agriculture worldwide is rain-fed, grown with green water. Rain-fed food requires no irrigation because the crop is sustained during the dry summer months with spring rainfall. But our global climate is moving us into unchartered territory. According to the United Nations World Water Report, our planet will warm anywhere between 2 and 11.5 degrees Fahrenheit within this century. Fred Pierce in his book, When the Rivers Run Dry, sums up the effect of climate change simply: “Wet places will get wetter and dry places will get drier.” Too much rain and too little rain will have tremendous impacts on agriculture.
It is anticipated that warmer temperatures will lead to about eight to ten percent more water cycling around our planet, enough to fill twenty Nile Rivers. We can expect to experience more intense rainfall events that will cause rivers to swell, widen, and spill ungracefully onto crop land.
Conversely, we can expect an increase of droughts and higher rates of evaporation that can reduce crop yields by up to one-third, causing farmers to use more irrigation, more blue water. If more crop acerage that has traditionally relied on rain is forced to utilize irrigation, what would that mean for already stressed water systems?
The uncertainty of our future climate makes the techniques implemented by dry farmers that much more significant. On a farm, tucked between a hillside and a vineyard, I learned that crops can be dry farmed like wheat, grapes, tomatoes, melons, olive trees, fruit trees, beans….and corn, the crop most devasted by the severe drought gripping the Midwest and Southwest. Dry farming is similar to rain-fed agriculture in that irrigation isn’t required, but dry farming involves more than just praying for rain. Dry farmers are able to farm in regions that receive scant amounts of rainfall, like Paso Robles, California.
To read more about dry farming read my past post Dry Farming and Water.