Scientists creating plants that make their own fertilizer
Since the dawn of agriculture people have exercised great ingenuity to pump more nitrogen into crop fields. Farmers have planted legumes and plowed the entire crop under, strewn night soil or manure on the fields, shipped in bat dung from islands in the Pacific or saltpeter from Chilean mines and plowed in glistening granules of synthetic fertilizer made in chemical plants.
No wonder Himadri Pakrasi’s team is excited by the project they are undertaking. If they succeed, the chemical apparatus for nitrogen fixation will be miniaturized, automated and relocated within the plant so that nitrogen is available when it is needed and where it is needed and only then and there.
“That would really revolutionize agriculture,” says Pakrasi, Ph.D., the Myron and Sonya Glassberg/Albert and Blanche Greensfelder Distinguished University Professor and Director of the International Center for Advanced Renewable Energy and Sustainability (I-CARES) at Washington University in St. Louis.
Engineering with biological parts
Much of modern agriculture relies on biologically available nitrogenous compounds (called “fixed” nitrogen) made by an industrial process, developed by German chemist Fritz Haber in 1909. The importance of the Haber-Bosch process, as it was eventually called, can hardly be overstated; today the fertilizer it produces allows us to feed a population roughly a third larger than the planet could sustain without synthetic fertilizer.
On the other hand, the Haber-Bosch process is energy intensive, and the reactive nitrogen released into the atmosphere and water as run-off from agricultural fields causes a host of problems, including respiratory illness, cancer, and cardiac disease.
Pakrasi thinks it should be possible to design a better nitrogen-fixing system. His idea is to put the apparatus for fixing nitrogen in plant cells, the same cells that hold the apparatus for capturing the energy in sunlight.
The National Science Foundation recently awarded Pakrasi and his team more than $2.3 million to explore this idea farther. The grant will be administered out of I-CARES, a university-wide center that supports collaborative research regionally, nationally, and internationally in the areas of energy, the environment, and sustainability.
This award is one of four funded by the National Science Foundation jointly with awards funded by the Biotechnology and Biological Sciences Research Council in the United Kingdom. The teams will collaborate with one another and meet regularly to share progress and successes.