It may be possible to produce fertilizer at the farm, using just sunlight and nitrogen from the air.

Titania - Titanium dioxide

A specialized X-ray source at Lawrence Berkeley National Laboratory, has aided researchers at the Georgia Institute of Technology to confirm the existence of a long-hypothesized interaction between #nitrogen and titanium dioxide (TiO2) – a common #photoactive material also known as #titania – in the presence of light. The catalytic reaction is believed to use carbon atoms found as contaminants on the titania. This might provide a sustainable way to produce Ammonia fertilizer, even at small scales by the farmers in the developing countries.
If this experimental process could be scaled up, it might one day help power clean farm-scale fertilizer production that could reduce dependence on capital-intensive centralized production facilities and costly distribution systems that drive up costs for farmers in isolated areas of the world. Most of the world’s fertilizer is now made using ammonia produced by the Haber-Bosch process, which requires large amounts of natural gas.

“In the United States, we have an excellent production and distribution system for fertilizer. However, many countries are not able to afford to build Haber-Bosch plants, and may not even have adequate transportation infrastructure to import fertilizers. For these regions, photocatalytic nitrogen fixation might be useful for on-demand fertilizer production. Ultimately, this might be a low-cost process that could make fertilizer-based nutrients available to a broader array of farmers, said Marta Hatzell, an assistant professor in Georgia Tech’s Woodruff School of Mechanical Engineering.
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