Alberta Soil Phosphorus Limits Project

Agricultural systems often require added phosphorus to achieve optimum crop and livestock production. The application of soil amendments, such as inorganic fertilizers, manure, biosolids, and waste water, can improve soil fertility and help produce optimum crop yields. However, many of these amendments, particularly organic materials such as animal manure, are often applied in excess of crop nutrient requirements. A build up of nutrients in the soil can be a significant risk to surface and groundwater quality. The movement of phosphorus from agricultural land to surface water can lead to accelerated eutrophication, which is recognized as a significant water quality problem in the many parts of the world (Johnston et al. 1997; Correll 1998; Haygarth and Jarvis 1999; Haygarth et al. 2000; Sharpley et al. 2000; Campbell and Edwards 2001).