Abstract Soil nitrogen (N) is one of the most important nutrients for plant productivity and microbial activity in terrestrial ecosystems. However, soil N is also readily affected by land management practices, influencing N 2 O emissions. This study assessed N dynamics in soil from different crop systems including a 1:2 (one row of maize and two rows soybean) and 2:3 (two rows of maize and three rows of soybean) intercrop and a maize and soybean sole crop as a result of residue addition from maize or soybeans. This was achieved through a 140-day incubation study using δ 15 N natural abundance. The effect of residue addition on soil TN was greater than its influence on crop systems when compared to treatments with no residue addition (Cont). The influence of residue addition on intercrops was most readily observed in the fractionated soil. Light fraction N (LF-N) and soil microbial biomass N (SMB-N) were significantly greater ( p p 15 N-TN, δ 15 N-LF and δ 15 N-SMB compared to Cont treatments. The δ 15 N-SMB was significantly enriched ( p p 2 O emissions than Cont treatments. However, N 2 O emissions were not significantly different ( p