Correct management practices should increase the manure fertilizer value and reduce the negative environmental impact of excess N in soils. The objectives of this study were to evaluate the efficacy of acidified and non-acidified manure on corn N uptake and grain yield relative to the effect of inorganic fertilizers on those parameters, and to compare manure and fertilizer N transformations over time. The experimental design was a RCBD with 4 reps. Five treatments consisted of 248 kg N/ha ¹⁵N labeled acidified manure (MA), 206 kg N/ha ¹⁵N labeled non-acidified manure (MNA), a control, and two rates of ¹⁵N labeled ammonium sulfate at 250 (AS250) and 125 kg N/ha (AS125). Soil samples were taken before and after treatment application, and soil and plant samples were taken at V3, V6, V12, R2 and R6. The fertilizer value of the incorporated MA was very similar to that of MNA since they produced similar corn yields and N uptake. Total N uptake in plant aerial biomass was highest for AS250, followed by the manured plots, then AS125, and then the control plots with the lowest N uptake. Corn yield was highest for AS250 (12,475 kg/ha), followed by AS125, MA and MNA that averaged 10,900 kg/ha. The highest plant N recovery was observed for the inorganic fertilizers, averaging 43%. ¹⁵N recovery was lowest in the manured plots (26%). Swine manure, when managed correctly, can produce corn yields comparable to an inorganic N fertilizer at 50% of the total manure N. On the other hand, we observed no nitrate leaching potential in the manured treatments, contrary to AS250 that produced 60 kg N/ha in soil that were available after plant uptake had ceased. Therefore, we consider that properly managed swine manure may be a valuable fertilizer both from a production and environmental point of view.