Results from the project show a positive grain yield response to field pea from fertilizer P addition, with maximum yields achieved at 40 kg P₂0₅/ha. These responses were recorded even though soil test P levels would have indicated P sufficiency. The spring wheat did not respond to P application rates. Pea grain N uptake was positively influenced by fertilizer P rates, with N uptake increasing with P rate. This occurred while no difference was observed in N uptake in the pea crop residue.
Soil test results show a very clear decline in soil test P levels in the absence, or with low rates of fertilizer P application. Only the 40 kg P₂0₅/ha fertilizer rate maintained soil test P at a level similar to the start of the study. We would like to evaluate seed P content as a means of determining the P balance (inputs vs removal) from the trial site.