Doyle, P.J.Cowell, L.E.Rennie, D.A.Campbell, C.A.2018-09-142018-09-141992-02-20http://hdl.handle.net/10388/10575Nutrient removal I replacement ratios were calculated in Manitoba, Saskatchewan, and Alberta from 1965 to 1989 by dividing total fertilizer (N, P, and K) sales by the total crop removal of plant nutrients. The nutrient removal I replacement ratios revealed that significant depletions of soil reserves of N, P, and K have taken place over the past 25 years. The average negative balance of N, P2O5, and K2O on the prairies is estimated at 640, 125, and 490 thousand tonnes. Even with the substantial increase in the use of fertilizers in the past five years compared to the 25 year average, the nutrient deficit continues to be unacceptably high for nitrogen (485,000 tonnes), only modest for phosphorus (86,000 tonnes), and as could be expected for potassium, has increased significantly to 570,000 tonnes. Overall, the calculations suggest that Manitoba is very close to nitrogen and phosphorus balance. Alberta has a relatively close balance, while Saskatchewan has not only experienced an unacceptably high N and P deficit for the past 25 years, but continues to do so at the present time.enAttribution-NonCommercial-NoDerivs 2.5 CanadaPresentation