The objectives of this experiment were to determine the power of Morin (sand) and Achigan (sandy-loam) soils to hydrolyze urea and to nitrify ammonium. The urea was applied at a rate of 1500 mg N/kg soil in a drill 6 cm below the soil surface. The soils were incubated for 63 days at 20 °C and 25% moisture content (vol/wt) in 2-L containers. The band-applied urea hydrolysis was directly proportional to the logarithm of its remaining concentration in the soil (i.e. first-order reaction). Calculated reaction rate constants were −0.112 and −0.143 per day for the sand and the sandy loam, respectively. The unequal reaction rates were, presumably, related to the different chemical and physical properties of these soils. The rate of urea ammonification was significantly more rapid than the ammonium nitrification. One week after starting the incubation, only 18.3% and 11.5% of the applied urea remained in the Morin and Achigan soils, respectively. However, no nitrification was detected until about the 20th day and it was more active in the sandy soil. Soil pH increased and decreased significantly as ammonification or nitrification progressed, respectively.