Impact Of Soil Enhancer Application On Soil Greenhouse Gas Emissions And Assessment Of Its Environmental Impact

Nitrification inhibitors and biochar applications hold considerable potential for mitigating greenhouse gas emissions from agricultural soils.However,their effectiveness in reducing emissions remains a subject of debate.This study employed an integrated analysis to investigate the effects of nitrification inhibitors and biochar applications on nitrous oxide emissions from agricultural soils.Seven treatments were examined through in situ monitoring to analyze soil CO₂,N₂O,and CH₄ flux,encompassing:（1）no nitrogen control,（2）urea,（3）slow-release fertiliser,（4）urea+dicyandiamide,（5）urea+biochar,（6）slow-release fertiliser+dicyandiamide,and（7）slow-release fertiliser+biochar.The impact of nitrification inhibitors and biochar additions on energy consumption,land use,warming,eutrophication,and environmental acidification in winter wheat was evaluated using life cycle assessment methods,shedding light on the combined environmental effects of these treatments.The results of this study offer novel insights into the effects of nitrification inhibitors and biochar applications on greenhouse gas emissions from agricultural land,as well as their combined impact on the environment.The main findings are as follows:（1）Both nitrification inhibitors and biochar applications significantly reduced soil nitrous oxide emissions.Nitrification inhibitors exhibited a higher reduction potential（37.4%）compared to biochar application（20.2%）.However,no significant difference was observed between the two treatments in terms of crop yield improvement（5.8%and 5.4%,respectively）.Among the nitrification inhibitors,dicyandiamide showed the greatest reduction potential（40.8%）,surpassing urease inhibitor（24.3%）and nitrification inhibitor+urease inhibitor（36.4%）.The amount of nitrogen applied and the trial duration were identified as key factors influencing nitrous oxide emissions under nitrification inhibitors and biochar applications,respectively.（2）The combination of urea+dicyandiamide demonstrated the best potential for reducing greenhouse gas emissions without affecting yield.The application of dicyandiamide,a nitrification inhibitor,significantly reduced soil CO₂ and nitrous oxide emissions in wheat fields.Moreover,combining slow-release fertiliser with dicyandiamide or biochar displayed a notable inhibitory effect on soil nitrous oxide emissions.However,the application of slow-release fertiliser,dicyandiamide,or biochar did not significantly impact winter wheat yield.（3）The combined environmental impact potential of treatments involving urea and nitrification inhibitors or biochar was lower compared to urea alone.Notably,the urea+biochar treatment exhibited the least combined environmental impact,primarily through reductions in greenhouse effect and eutrophication potential during the life cycle of winter wheat.The highest land use criteria values for winter wheat were observed with the application of slow-release fertiliser and urea+dicyandiamide.The greenhouse effect criteria were similar for the urea+dicyandiamide and urea+biochar application treatments,while the eutrophication criteria were lower for the urea+dicyandiamide treatment compared to other treatments.However,the environmental acidification criteria were higher in the urea+dicyandiamide treatment.