Greenhouse gas emissions from the growing season are regulated by precipitation events in conservation tillage farmland ecosystems of Northeast China.

Reducing greenhouse gas (GHG) emissions from agricultural ecosystems is vital to mitigate global warming. Conservation tillage is widely used in farmland management to improve soil quality; however, its effects on soil GHG emissions remain poorly understood, particularly in high-yield areas. Therefore, our study aimed to evaluate the effects of no-tillage (NT) combined with four straw-mulching levels (0 %, 33 %, 67 %, and 100 %) on GHG emission risk and the main influencing factors. We conducted in-situ observations of GHG emissions from soils under different management practices during the maize-growing season in Northeastern China. The results showed that NT0 (705.94 g m) reduced CO emissions by 18 % compared to ridge tillage (RT, 837.04 g m). Different straw mulching levels stimulated NO emissions after rainfall, particularly under NT combined with 100 % straw mulching (2.89 kg ha), which was 45 % higher than that in any other treatments. The CH emissions flux among different treatments was nearly zero. Overall, straw mulching levels had no significant effect on the GHG emissions. During the growing season, soil NH-N (< 20 mg kg) remained low and decreased with the extension of growth stage, whereas soil NO-N initially increased and then decreased. More importantly, the results of structural equation modeling indicate that: a) organic material input and soil moisture are key factors affecting CO emissions, b) nitrogen fertilizer and soil moisture promote NO emissions, and c) climatic factors exert an inexorable influence on the GHG emissions process. Our conclusions emphasize the necessity of incorporating precipitation-response measures into farmland management to reduce the risk of GHG emissions.