【摘要】 为探究沼液还田影响下土壤NO₃^--N的累积变化特征,明确NO₃^--N累积影响因素的重要性,在“中国知网”与“web of science”两个数据库中筛选了19篇有效文献和153个有效数据对,采用meta分析研究了沼液施用水平、施用深度、施用年限、耕地利用方式等人为因子与土层深度、土壤pH值、土壤有机质等自然因子对土壤NO₃^--N累积的影响,借助随机森林模型与无序变量多元回归方法评价了各影响因子的重要性.结果表明,中、低施氮水平及长期施用沼液会使土壤中NO₃^--N显著累积,效应值分别为192.44%、194.37%和386.81%,存在较大NO₃^--N淋失风险;沼液还田后SOM及pH值是土壤NO₃^--N累积的主要影响因素,在SOM含量为10～40g/kg时NO₃^--N效应值为266.87%（p<0.05）,pH<6.5时其效应值为240.01%（p=0.07）,因此应优先关注SOM较丰富和土壤酸化严重地区的沼液施用情况;NO₃^--N累积效应空间分布存在明显差异,以东北地区及西南丘陵地区（广西、重庆）累积最为明显,响应比分别为3.43、2.39和1.63.研究结果可为沼液的安全利用提供科学依据.更多还原

【Abstract】 In order to explore the characteristics of changes in soil NO₃^--N accumulation under the influence of biogas slurry returning to field and clarify the important factors influencing this accumulation,19 valid studies and 153 valid data pairs were screened from two databases—the China National Knowledge Network and Web of Science.The effects of human factors,including application level,application depth,application years,and land use,as well as natural factors,such as soil depth,soil pH,and soil organic matter （SOM）,on soil NO₃^--N accumulation were studied using a meta-analysis.The importance of each influencing factor was evaluated using a random forest model and the disordered variable multiple regression method.The results showed that soil NO₃^--N accumulation was significant at medium and low nitrogen application levels and at long-term biogas slurry application,with effect values of 192.44%,194.37%,and 386.81%,respectively.There was a greater risk of the leaching of NO₃^--N.SOM and the pH of biogas slurry were the main factors influencing soil NO₃^--N accumulation.The effect values of NO₃^--N accumulation was266.87%（p<0.05） and 240.01%（p=0.07） when the SOM content was approximately 10～40g/kg and p H was<6.5,respectively.Therefore,biogas slurry application in areas with rich SOM and severe soil acidification should be prioritized.The spatial distribution of NO₃^--N accumulation was significantly different.Accumulation was the most evident in northeast China and the southwestern hilly areas of Guangxi and Chongqing,with response ratios of 3.43,2.39,and 1.63,respectively.These results provide a scientific basis for the safe application of biogas slurry.更多还原