Agricultural sources of phosphorus (P) are associated with eutrophication in Alberta. To develop a basis for P limits, a multi-year, field-scale study relating soil test P (STP) and total P in runoff (TP) was started in 2002 at seven cultivated sites (22 to 248 ha). Five sites were non-manured and two were manured. Soil samples were taken each fall and spring at 0 to 2.5, 2.5 to 5, and 5 to 15 cm and analysed for STP and degree of P saturation (DPS). Mean STP in 0 to 15 cm in fall 2002 ranged from 20 to 35 mg kg-1 at the non-manured sites, and from 269 to 512 mg kg-1 at the manured sites. Mean STP in 0 to 2.5 cm was up to 1.9 times greater than in 0 to 15 cm. In spring 2004, STP at the non-manured sites increased by up to 1.8 times, although STP at the manured sites decreased by up to 0.5 times after no further manure additions. The DPS in 0 to 15 cm was less than 15% at the non-manured sites and increased to 99% at the heavily manured site. Sites were instrumented with flumes to measure runoff volumes and water samples were collected for analysis. Snowmelt generated 96% of the runoff in 2003 and 2004. Flow weighted mean concentrations of TP in runoff ranged from 0.22 to 0.82 mg L-1 at the non-manured sites and increased by at least one order of magnitude at the manured sites, to between 1.97 and 29.10 mg L-1. All measures of STP and DPS were significantly related to TP in runoff and relationships improved with decreased soil depth. However the form of the relationship is unclear and it is hoped that a third year of data will help to clarify this.