Commercial fertilizers, they say, are responsible for 40% to 60% of current U.S. food production. And, for more than 40 years, removal of the three primary plant nutrients by crops in the U.S. has been increasing linearly at rates of 70,000; 51,000; and 67,000 Mt of N, P and K per year, respectively.
Application of new fertilizers have been enough to sustain cropping practices as of recent, but the report authors note that nutrient budget deficits must stabilize in the future to encourage enhanced productivity. Further, additional nutrients used as part of bioenergy cropping will amplify the need for P and K resources. One option: improved filters for waste streams and farm runoff.
Nitrogen isn't out of the woods, either, researchers write. By 2050, N use is projected to increase 44% from current levels. Precision applications are offered as a way to minimize N use, though the report notes that even technology won't eliminate N applications.
Though precision farming, genetic modification, and cellulosic fuel technologies offer promise for feeding and fueling the next generations, authors reinforce that biofuel demand has a heavy hand in nutrient use. Research and development, they say, could be the best bet for integrating the food, feed and fuel industries for maximum efficiency and nutrient recovery.
CAST paper authors include David Zilberman, University of California–Berkeley; Paul E. Fixen, International Plant Nutrition Institute; Bruce Dale, Michigan State University; and John L. Havlin, North Carolina State University.
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