Soil aeration is a key parameter for sustainable and productive agriculture. The intensification of agricultural activity in Greenland involves land use (LU) and LU change, affecting the soil–air phase. The combined effects of natural compaction (bulk density, ρ_b), texture (texture uniformity index; TUI), and LU on the soil–air phase of subarctic soils are not well known. This study aims to identify and compare the main drivers for air-filled porosity (ε) and soil-structure changes within and across sites in Greenland and Denmark. We analyzed comprehensive data sets of ε, relative gas diffusivity D_p/D_o), and air-permeability (k_a) measured on intact soil samples from South Greenland (pasture) and Denmark (cultivated, urban, and forest). The mechanical robustness of the air phase was evaluated by linear models of ε as a function of ρ_b (H-model). The ratio of k_a to D_p/D_o served as a soil-structure index (Ω); the latter significantly correlated to TUI. The Greenlandic pasture soils did not show signs of well-developed soil structure (low Ω-values), whereas low H-values suggested the soils were mechanically robust compared to similar-textured cultivated soils. The soil–air characteristic curve (ε vs. pF) was parameterized, and the moisture control parameter was accurately predicted by TUI and LU (R² = .95). Overall, the ρ_b was found to control the air-phase functions within a field. However, considering changes in ε-levels across different fields, texture, LU, and other environmental factors became statistically more relevant than ρ_b. A modeled response surface for changes in ε with soil conditions may, in perspective, be useful for better-predicting gas transport in soil, both within and across fields.

中文翻译：

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土壤-空气相特征：对格陵兰岛和丹麦的质地、密度和土地利用的响应

土壤通气是可持续和高产农业的关键参数。格陵兰农业活动的集约化涉及土地利用 (LU) 和 LU 变化，影响土壤-空气阶段。自然压实（体积密度，ρ _b）、质地（质地均匀性指数；TUI）和 LU 对亚北极土壤的土壤-空气相的综合影响尚不清楚。本研究旨在确定和比较格陵兰和丹麦场地内和场地间充气孔隙率 (ε) 和土壤结构变化的主要驱动因素。我们分析了 ε、相对气体扩散率D _p / D _o ) 和透气性 ( k _a) 对来自南格陵兰（牧场）和丹麦（耕地、城市和森林）的完整土壤样本进行测量。气相的机械稳健性通过作为 ρ _b函数的 ε 线性模型进行评估（H 模型）。k _a与D _p / D _o的比值作为土壤结构指数 (Ω)；后者与 TUI 显着相关。格陵兰牧场土壤没有显示出土壤结构发育良好的迹象（低 Ω 值），而低H- 值表明与类似质地的栽培土壤相比，土壤具有机械强度。土壤-空气特征曲线（ε vs. pF）被参数化，水分控制参数通过 TUI 和 LU 准确预测（R ²  = .95）。总的来说，发现ρ _b控制场内的空气相函数。然而，考虑到不同领域 ε 水平的变化，纹理、LU 和其他环境因素在统计上变得比 ρ _b更相关。从角度来看，ε 随土壤条件变化的模拟响应面可能有助于更好地预测田间和田间土壤中的气体传输。