The smart farming system uses a copper-based hydrogel that captures excess nitrate waste from fertilizer runoff and transforms it into ammonia—a critical element in fertilizers—that can then be reused. In tests, the system had the ability to match or increase crop yields over traditional methods while also minimizing environmental impacts.

"We designed this system and showed that it can grow the same or more crops without overusing nitrogen, which can contaminate groundwater and lead to harmful greenhouse gases," said Guihua Yu, a professor of materials science in the Cockrell School of Engineering's Walker Department of Mechanical Engineering and Texas Materials Institute.

The study, published in the Proceedings of the National Academy of Sciences, shows that the copper-based gel film not only produces ammonia from nitrate waste but also senses nitrogen levels in the soil. This detection capability helps determine the optimal time to drain nitrate, a nitrogen compound that is important for plant growth but can be a pollutant, from the soil to convert to ammonia, keeping it from escaping and contaminating the surrounding environment.