The phosphorus cycle is shown in the diagram below

Last updated: 4/14/2023

The phosphorus cycle is shown in the diagram below Weathering of phosphate rocks Soil surface OB Phosphate fertilizer source OA I II and III only I and II only OC Residues II and IV only Plants Organic matter O Plant uptake Removed from cycle by harvesting Decomposition and excreta Insoluble phosphates According to the diagram which of the following are sources of phosphorus 1 weathering of phosphate rocks II phosphate fertilizers III decomposition and excreta IV the air Leaching Agency Image courtesy of the United States Environmental Pr