Balancing maize yield and greenhouse gas emissions: The integrated effects of no-till, straw return, and nitrogen rates

Fertilizer application and tillage are well-known drivers of soil greenhouse gas (GHG) emissions. Most previous studies have focused on a single factor affecting GHG, but their interactive effects remain poorly understood. In arid or semi-arid region of northeastern China, straw returning is widely practiced but its combined influence with nitrogen (N) application on crop productivity and GHG is unclear. This study aimed to evaluate whether no-tillage with straw return could reduce nitrogen use and mitigate GHG emissions while maintaining maize yield. A two-year field experiment was conducted with five treatments: i) no straw return + conventional tillage (S0N1CT), ii) no straw return + no-tillage (S0N1NT), iii) full straw return + no N (SN0NT), iv) full straw return + 225 kg N ha −1 + no-tillage (SN1NT), and v) full straw return + 335 kg N ha −1 + no-tillage (SN2NT). Soil temperature, moisture, nitrate, GHG fluxes, and maize yield were measured and net ecosystem carbon budget (NECB), net global warming potential (NGWP), and carbon footprint (CF) calculated. Compared with S0N1CT, SN1NT treatment reduced cumulative CO 2 , N 2 O, and CH 4 emission by 7.9–10.0 %, 17.9−18.2 %, and 20.7−21.3 %, respectively. It also resulted in enhanced soil organic carbon (24.8−27.2 %), improved NECB (1322−1748 kg ha −1 ), and decreased NGWP (11,400−12,480 kg ha −1 ) and CF (0.06−0.08 kg ha −1 ) while sustaining high grain yield (∼10,000 kg ha −1 ). Full straw return under no-tillage with a moderate N rate (225 kg ha −1 ) simultaneously improved carbon sequestration, reduced GHG emissions, and maintained high maize yield. This integrated management practice would be an effective strategy for climate-smart and sustainable agriculture production in the semi-arid regions of China. • Straw mulching with nitrogen fertilizer reduced greenhouse gas emissions compared with traditional tillage. • Full straw mulching with 225 kg ha −1 nitrogen showed the lowest emissions. • The study identified an optimal straw–nitrogen management strategy for arid and semi-arid farmland.