Introduction: There is limited knowledge about how co-applying organic fertilizer and zeolite influences maize yield and soil greenhouse gas (GHG) emissions in sandy loam soil.Methods: In the present study, a 3-year maize field experiment was conducted on a sandy loam soil in the North China Plain with five treatments: no added fertilizer (control, CK), synthetic fertilizer (SF), organic fertilizer replacing 30% synthetic N fertilizer (OF), synthetic fertilizer with zeolite (ZSF), and organic fertilizer with zeolite (ZOF).Results: Results showed that, compared with the SF treatment, the ZOF treatment significantly increased yield by 14.72–23.61% in each of the 3 years, ZSF by 13.91–15.59% in 2022 and 2023, and OF by 16.92% in 2023. Compared with ZSF, the cumulative CO₂ emission was significantly increased by 4.52% in OF in 2023. Compared with SF, the average N₂O emission flux and cumulative (over 2022 and 2023) N₂O emissions were significantly reduced by 6.74–8.23% and 6.10–8.79% by OF, 9.29–11.86% and 9.23–10.85% by ZSF, and 7.59–11.24% and 12.27–16.06% by ZOF, respectively. Compared with SF, the total global warming potential (GWP) was significantly lower by 4.78% in ZOF in 2023, the greenhouse gas intensity (GHGI) was significantly lower over the 3 years of trials by 6.45–15.31% and 14.16–21.06% in treatments ZSF and ZOF, respectively, and was significantly lower by 10.53–13.13% in OF in 2022 and 2023. Compared with SF, the levels of available potassium and phosphorus content, dissolved organic carbon content, soil β-glucosidase activity, and microbial biomass carbon and nitrogen concentration in the ZOF treatment were significantly higher by 7.34, 8.90, 19.48, 9.20, 8.42, and 11.29%, respectively; however, soil NH₄⁺-N and NO₃⁻-N were significantly lower by 9.08 and 9.30%, respectively. The beneficial yield effects were due mainly to the enhanced synchronization of nutrient availability, soil moisture, and microbial biomass, while the mitigation of N₂O emission was mainly attributed to the decreasing soil NO₃⁻ and NH₄⁺ concentrations in response to ZOF.Conclusion: Applying both organic fertilizer and zeolite achieved increased maize yield and positive environmental benefits. This strategy could be adopted to improve maize production, mitigate greenhouse effects caused by N₂O emissions, and improve soil quality in sandy loam soils.

To investigate the impacts of the continuous application of urban sewage sludge on heavy metal pollution risks in wine grape orchards, this study conducted a five-year field plot experiment using wine grapes as the test crop. The experimental design included three sludge application rates and a control without sludge application. Soil physicochemical properties, the single-factor and integrated pollution indices (PI and NIPI) of heavy metals, potential ecological risk indices (EI and RI), and the safe application duration of sludge were analyzed. The results suggest that sludge application significantly increased soil organic matter, total nitrogen, total phosphorus, and available phosphorus by 39.99–46.56%, 59.37–73.69%, 83.57–143.19%, and 88.79%, respectively, while reducing soil bulk density by 8.70–27.92%. The PI and EI of Cd exhibited significant linear increases with the duration of sludge application, with annual increments of 0.010 and 0.31, respectively. Hg was influenced by both the application rates and duration, with annual increments of 0.013 and 0.52 for the PI and EI, respectively. These two elements collectively drove overall increases of 7.31–24.96% in NIPI and 32.51–59.90% in RI, with mean annual increases of 0.0064 and 0.84, respectively. In contrast, Cr, Pb, and As showed no significant changes. Based on the calculated environmental capacities of Cd and Hg, the safe application durations were estimated to be 46.99–126.93 and 48.58–131.21 years, respectively. These results demonstrate that under the current application intensity, sludge can improve soil fertility in the short term with controllable ecological risks. However, considering their potential environmental risks, the continuous accumulation of Cd and Hg necessitates vigilance.