Keeping More Ammonium In Soil Could Decrease Pollution, Boost Crops Modern-day agriculture faces two major dilemmas: how to produce enough food to feed the growing human population and how to minimize environmental damage associated with intensive agriculture. Keeping more nitrogen in soil as ammonium may be one key way to address both challenges, according to a new paper(link is external) in the Proceedings of the National Academy of Sciences (PNAS). Today’s use of nitrogen fertilizers contributes heavily to greenhouse gas emissions, air pollution, and water pollution, but they are also essential for growing crops. Reducing this pollution is critical, but nitrogen use is likely to grow with increased food production. At the same time, the world’s human population is increasing, and agriculture needs to efficiently produce enough food to feed everyone without resorting to clearing more forests for agriculture.