Plastic film mulching (FM) is widely used to increase crop yields and nitrogen (N) use efficiency. Slow-release fertilisers (SRF) and nitrification inhibitors (e.g., dicyandiamide [DCD]) are promising for reducing soil N losses, but their combined effects on N balance and carbon footprints (CF) in dryland spring maize systems remain unclear. A 3-year field experiment on China's Loess Plateau evaluated two cropping patterns: non-mulching (NM) and FM, combined with three fertilisers: conventional urea (CU), SRF and urea with DCD (UD). The study assessed N loss pathways (N2O, NH3, NO3 - leaching), N mineralisation, maize yield and CF. Both FM and SRF/UD reduced NO3 - leaching, with FM-SRF being most effective while achieving the highest yield (13,981 kg ha-1). FM and SRF/UD had contrasting effects on N2O and NH3, with FM exerting a greater influence. FM increased N2O but decreased NH3, with the smallest N2O rise in FM-UD and the largest NH3 reduction in FM-SRF. Primary N loss pathways were NO3 - leaching (16%-52%) and NH3 volatilisation (53%-83%). FM's impact on CO2 emissions was smaller than fertilisation effects; FM-SRF minimised N mineralisation, enhancing soil organic carbon (SOC) storage and reducing CO2 emissions. FM-SRF achieved the lowest greenhouse gas intensity (GHGI: 0.017 kg CO2-eq k g-1). Delta SOC dominated total CF (26%-62%), while N loss contributions were minor (3.4%-8.8%). FM-SRF achieved the lowest total CF (4680 kg CO2-eq ha-1) and lowest CF per unit yield. Thus, SRF is optimal for film mulching spring maize systems, ensuring low CF and N losses in Loess Plateau drylands.