Use of Source-Separated Human Urine to Enrich an Ultisol of the Southern Coastal Plain of the United States

Abstract

Source-separated human urine (SSHU), human urine intentionally diverted and kept separate from feces, has many environmental and agronomical uses. The principal objectives of this research were to investigate SSHU use in composting high C:N ratio oak (Quercus virginiana) leaves and in growing collard green (Brassica oleracea) for human consumption. Two batches of first morning SSHU were collected from 14 and 20 individuals, inclusively. SSHU was added to oak leaves with high C:N ratio and equilibrated for a long time to facilitate composting. This research demonstrated that SSHU can be diverted from wastewater treatment facilities, significantly decreasing the C:N of oak leaves to improve composting while significantly increasing NO3-N, P, K, S, Na, Cl- and pH. Although collard green responded to SSHU, demonstrating that it can be used as a fertilizer, it performed poorly compared to a chemical fertilizer and was harmful at 166 ppm total N level.