<p>Nitrification inhibitors (NIs) effectively reduce nitrogen (N) loss and enhance fertilizer use efficiency, leading to higher yields. While both NIs and crop residues reduce nitrification, their combined effects on N availability from different sources (soil, fertilizer, and residue) and plant uptake require further investigation. This study utilized a ¹⁵N double-labeling field experiment (¹⁵N-labeled residue with nonlabeled fertilizer and ¹⁵N-labeled fertilizer with nonlabeled residue) to assess these effects. The treatments included (¹⁵NH₄)₂SO₄ with and without 3,4-dimethylpyrazole phosphate (DMPP) at two residue levels. The measured parameters included soil mineral N availability (¹⁵N-NO₃⁻ and ¹⁵N-NH₄⁺), ¹⁵N recovery, and yield components. The results indicate that NIs significantly increased wheat grain and straw yields by approximately 32% and 20%, respectively, at high residue application rate (10 t ha⁻¹). The combined use of NIs and residues increased the available N from all three sources (fertilizer, soil, and residue). Nitrification inhibitor application resulted in increases of approximately 37% and 74% in nitrogen use efficiency from the fertilizer source at residue application rates of 5 and 10 t ha⁻¹, respectively. Concerning nitrogen use efficiency from the residue, NI does not affect it. Residue application alone was insufficient to meet crop N demand, but its utility improved significantly when it was supplemented with chemical fertilizers. Additionally, the combined effect of NIs and residues mitigated the inhibitory processes associated with nitrification suppression. In conclusion, if farmers incorporate wheat residues into the soil through plowing, applying NIs is recommended to maintain yield and nitrogen use efficiency.</p>