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Straw return with chemical fertilizers is integral to improving soil quality and the sustainability of agricultural production. However, little is known about how straw return with chemical fertilizer application affects CO2 emissions and carbon pools from the perspective of nutrient stoichiometry. We conducted a 2‐year (2020–2021) field experiment in a wheat–maize rotation system in silty clay loam to study the effects of straw return and fertilizer application on CO2 emissions, soil carbon pools and yields by applying stoichiometry. A split‐plot experimental design was used (straw was main treatment, and fertilizer was the split‐plot treatment). The treatments were no straw return + no fertilizer (S0W), no straw return + mineral nitrogen fertilizer (S0N), no straw return + mineral nitrogen and phosphorus fertilizer (S0NP), straw return + no fertilizer (SW), straw return + mineral nitrogen fertilizer (SN) and straw return + mineral nitrogen and phosphorus fertilizer (SNP). The results indicated that, compared with S0W, the SNP treatment significantly increased soil organic carbon (SOC) storage by 17% and 13% in the 0–20 cm and 20–40 cm soil horizons, respectively. Additionally, compared with S0W, the SNP and SN treatments significantly increased the annual cumulative CO2 emissions by 85% and 41%, respectively. Furthermore, the SNP and SN treatments significantly increased the annual yield by 61% and 38%, respectively, compared with S0W. Our results indicated that straw and fertilizer inputs reduced the C:Nimbalance in the topsoil (0–20 cm), with fertilizer inputs showing a more pronounced effect. However, straw incorporation increased the C:Nimbalance in subsoil (20–40 cm). Redundancy analysis (RDA) and structural equation models (SEM) suggested that 0–20 cm carbon‐phosphorus ratio (C:P) and nitrogen‐phosphorus ratio (N:P) could be significant predictors of annual yield and CO2 emissions. In conclusion, straw and fertilizers enhanced soil nutrient effectiveness and reduced carbon mineralization in favour of SOC storage. However, the input of exogenous materials (straw and fertilizers) disrupted the soil ecological stoichiometric balance and stimulated microbial activity, leading to increased CO2 emissions. Overall, this study provides theoretical guidance and scientific support for the green development of agriculture. [ABSTRACT FROM AUTHOR]

Sustainable agriculture systems incorporate important stabilizing mechanisms, such as mulching, for increasing yield and improving soil health. However, the synergistic effects of different long-term mulching practices on soybean yield stability and soil health remain unexplored. In this study, we conducted a 13-year long-term investigation to evaluate the impacts of various mulching methods—no mulching (CK), straw mulching (SM), plastic mulching (PM), and ridged and plastic mulching (RM)—over a 13-year period on soil nutrients, and soybean yield, stability, and sustainability. Our findings revealed that SM, PM, and RM treatments significantly increased the average yields by 28.02 %, 20.49 %, and 51.56 %, respectively. Moreover, SM and RM treatments significantly enhanced yield stability (SM +107.90 %, RM +98.82 %) and sustainability (SM +47.85 %, RM +37.14 %). Additionally, compared to CK, the SM treatment significantly increased the average soil organic carbon (SOC) and total nitrogen (STN) content by 16.78 % and 16.23 %, respectively. Meanwhile, mulching practices also improved soil reactive carbon and nitrogen pools. Compared to CK, plastic mulch reduced microbial biomass carbon (MBC) content (PM −8.85 %, RM −0.73 %) and soil ammonium nitrogen (AN) content (PM −8.19 %, RM −1.20 %), while increasing microbial biomass nitrogen (MBN) content (PM +8.73 %, RM +9.47 %). The SM treatment increased MBC, AN, and MBN contents by 0.24 %, 7.23 %, and 8.94 %, respectively. Additionally, SM and RM treatments significantly increased β-1,4-glucosidase (BG) activity (SM +98.74 %, RM +128.25 %) and decreased and β-1,4- n -acetamido-glucosidase (NAG) + 1-leucine aminopeptidase (LAP) (NAG + LAP) activity (SM −28.74 %, RM −25.33 %) compared to CK. Furthermore, SM, PM, and RM treatments significantly increased the Chao1 index by 35.30 %, 68.08 %, and 52.23 %, respectively, compared to CK. Finally, results of the Mantel test and random forest model indicated that the increases in yield and stability were due to improved soil temperature (ST), active carbon and nitrogen pools, enzyme activity, and diazotrophic bacterial diversity. In summary, our findings suggest that ridged and plastic mulching enhances soil nutrient effectiveness by maintaining soil moisture and regulating diazotrophic bacterial community structure, thereby increasing soybean yields. Conversely, straw mulching continuously supplies nutrients to the soil, enhancing soil quality and diazotrophic bacterial community structure, thus improving yield stability. Over all, our findings provides new insights into global long-term agricultural sustainability. [Display omitted] • Straw mulching (SM) and ridged mulching (RM) improve soybean yield and stability. • SM treatment significantly increased the soil organic carbon and total nitrogen. • SM treatment improve soil health, favoring improved soybean yield stability. • RM treatment increase soil nutrient by maintaining soil moisture and increase yields. [ABSTRACT FROM AUTHOR]

Straw incorporation with half-plastic film mulch is a promising approach for enhancing soil quality in dryland farming. However, its effects on soil greenhouse gas (GHG) and NH 3 emissions remain poorly understood. This study aims to optimize the mulch practice to balance the plastic film input with comprehensive benefits and examine the temporal dynamics and influencing factors of soil GHG and NH 3 emissions. A 3-year field experiment was conducted in a wheat-maize cropping system in north-western China with a complete randomized design including three treatments replicated thrice: (a) no straw incorporation or half-plastic film mulch (CT), (b) straw incorporation without half-plastic film mulch (S), and (c) straw incorporation with half-plastic film mulch (SP). The study revealed that S treatment significantly enhanced crop yield and soil cumulative N 2 O, CO 2 , and NH 3 emissions during the maize season by 8.26%, 113.51%, 31.78%, and 64.92%, respectively, compared to CT treatment. SP treatment significantly decreased N 2 O and NH 3 emissions by 30.66% and 23.74%, respectively, and slightly stimulated CO 2 emissions by 8.73% relative to S treatment throughout the three maize seasons. The average maize yield gap between S and SP treatments ranged from 517 to 800 kg ha−1. N 2 O and NH 3 emissions were significantly associated with soil water content (SWC), soil N components, and enzyme activity (nitrate and nitrite reductase), whereas CO 2 emissions were significantly influenced by soil temperature. Compared with S treatment, half-plastic film mulch increased SWC (16.77%), reduced soil N content and inhibited activity of nitrate (12.15%) and nitrite reductase (8.40%), eventually mitigated straw incorporation-induced N 2 O and NH 3 emissions by 30.66% and 23.74%, respectively. Overall, we demonstrated that straw incorporation with half-plastic film mulch is an innovative practice for enhancing the sustainability of dryland farming by increasing maize yield and mitigating N 2 O and NH 3 emissions. [Display omitted] • Nitrogen cycle- related enzyme activities are key to regulating gas emissions. • S significantly increased N 2 O, CO 2 , and NH 3 emissions compared with CT. • SP significantly reduced N 2 O and NH 3 emissions and increased yield compared to S. • SP is an innovative practice for promoting the sustainability of dryland farming. [ABSTRACT FROM AUTHOR]