Agricultural soils are important sources of greenhouse gases (GHGs). Soil properties and environmental factors have complex interactions which influence the dynamics of these GHG fluxes. Four arable and five grassland soils which represent the range of soil textures and climatic conditions of the main agricultural areas in the UK were incubated at two different moisture contents (50 or 80% water holding capacity) and with or without inorganic fertiliser application (70 kg N ha⁻¹ ammonium nitrate) over 22 days. Emissions of N₂O, CO₂ and CH₄ were measured twice per week by headspace gas sampling, and cumulative fluxes were calculated. Multiple regression modelling was carried out to determine which factors (soil mineral N, organic carbon and total nitrogen contents, C:N ratios, clay contents and pH) that best explained the variation in GHG fluxes. Clay, mineral N and soil C contents were found to be the most important explanatory variables controlling GHG fluxes in this study. However, none of the measured variables explained a significant amount of variation in CO₂ fluxes from the arable soils. The results were generally consistent with previously published work. However, N₂O emissions from the two Scottish soils were substantially more sensitive to inorganic N fertiliser application at 80% water holding capacity than the other soils, with the N₂O emissions being up to 107 times higher than the other studied soils.

中文翻译：

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在受控条件下隔离土壤特性对农业土壤温室气体排放的影响

农业土壤是温室气体 (GHG) 的重要来源。土壤特性和环境因素具有复杂的相互作用，这些相互作用会影响这些温室气体通量的动态。代表英国主要农业区土壤质地和气候条件范围的四种可耕地和五种草地土壤在两种不同的水分含量（50% 或 80% 的持水量）和施用或不施用无机肥料（70 kg N ha⁻¹ 硝酸铵）超过 22 天。每周两次通过顶空气体采样测量 N2O、CO2 和 CH4 的排放，并计算累积通量。进行了多元回归模型以确定哪些因素（土壤矿物质 N、有机碳和总氮含量、C:N 比、粘土含量和 pH 值）最能解释 GHG 通量的变化。发现粘土、矿物氮和土壤碳含量是本研究中控制温室气体通量的最重要的解释变量。然而，没有一个测量变量可以解释耕地土壤中二氧化碳通量的显着变化。结果与以前发表的工作基本一致。然而，两种苏格兰土壤的 N2O 排放量在 80% 的持水能力下对无机氮肥施用比其他土壤更敏感，N2O 排放量比其他研究土壤高出 107 倍。结果与以前发表的工作基本一致。然而，两种苏格兰土壤的 N2O 排放量在 80% 的持水能力下对无机氮肥施用比其他土壤更敏感，N2O 排放量比其他研究土壤高出 107 倍。结果与以前发表的工作基本一致。然而，两种苏格兰土壤的 N2O 排放量在 80% 的持水能力下对无机氮肥施用比其他土壤更敏感，N2O 排放量比其他研究土壤高出 107 倍。