Pulse emissions of soil trace gases (carbon dioxide: CO2, nitrous oxide: N2O, and nitric oxide: NO) following the wetting of dry soils may contribute disproportionately to total annual trace gas emissions in drylands. These pulses are driven by coupled biotic-abiotic processes that are challenging to partition. Here we measured soil trace gases emissions after the wetting of gamma-irradiated and live intact cores of soils with different soil C and N pools, exchangeable cations, and microbial activity. For all soils, the emissions pulse of CO2 and N-oxides was measured within 5 min of wetting. Post-wetting CO2 emission pulses from the live soils were approximately twice as large as those from the gamma-irradiated soils and were correlated with soil C content. However, the gamma-irradiated soil emitted up to 5 times more N2O and up to 13 times more NO compared with the live soil and emissions were correlated with soil N content. After normalization against the soil inorganic N content, the immediate post-wetting N2O and NO emissions were the same from the live and gamma-irradiated soils. The dependence of the post-wetting N2O and NO burst on substrate pools, regardless of the presence of live microbes, suggests an abiotic origin of immediate post-wetting fluxes.