The ever-increasing cost of N fertilizer dictates the need for more efficient use of this nutrient in the future. This then demands that an accurate assessment be made of the N supply that can be expected from a soil. The latter depends on a soil's innate capacity or potential to supply N, as well as such intensity factors as moisture and temperature. At Swift Current, we have begun a study to determine rates of N mineralization in a representative cross section of Saskatchewan soils as influenced by cultivation, soil moisture, and temperature. This paper reports on some of our preliminary findings.