Urban land occupies 5% of the United States' land area, with turfgrass occupying 2%. These areas are often highly managed with irrigation and fertilization. This can lead to high greenhouse gas emissions and climate impacts. To combat this, some cities are beginning to use compost and recycled water to manage their fields.

To assess the impacts compost and recycled water way have, we conducted a two year long field experiment along with a three month intensive greenhouse experiment. We found compost increase carbon dioxide emissions while decreasing nitrous oxide emissions. The increase in carbon dioxide, along with additional plant growth, points to a more active soil system after compost additions. Decreases in nitrous oxide emissions are vital as nitrous oxide is 300 times more potent in global warming compared to carbon dioxide. We also observed decreases in NOx emissions in the field and increases in ammonia emissions in the greenhouse with compost additions. We did not, however, find major differences between the recycled water and filtered water irrigated treatments.

Overall, compost use in urban soils may be able to limit nitrous oxide emissions in areas where there are already high nitrogen loads, while continuing to support biological activity.