Soil pores can be functionally classified into macro-, meso- and micropores. The volume of these pores is highly affected by constitutive and state components of soils, such as particle size distribution and degree of compactness. In this study, we aimed to examine the impact of soil texture and degree of compactness on total porosity, and distribution of macro-, meso- and micropores. Undisturbed soil cores were taken in eight differently textured soils cultivated with sugarcane and equilibrated at matric potentials of − 30 and − 100 hPa for calculation of macropores (effective pore diameter – EPD > 100 µm), mesopores (EPD 100–30 µm) and micropores (EPD < 30 µm). The volume of each pore category was modelled using additive spline functions of soil particle size and degree of compactness. Soil organic carbon and mean weight diameter of soil aggregate (MWD) were also measured to support the findings. Total porosity and macropores were dependent on the degree of compactness and silt plus clay content, whereas silt plus clay content significantly affected meso- and micropores. Total porosity and macroporosity decreased with increasing compactness, mainly for soils with silt plus clay content lower than ~500 g kg⁻¹; especially for the macropores, these decreases were substantially reduced for further increase in silt plus clay content (> 500 g kg⁻¹) due to the higher MWD verified for these soils. Mesopores were predominant in soils with lower silt plus clay content, while their volume was practically null in soils with silt plus clay content higher than 500 g kg⁻¹, for which only macro- and micropores were observed. In conclusion, the increased degree of compactness may reduce both total porosity and macroporosity in a process whose magnitude depends on soil texture, whereas meso- and micropores have major changes associated only with particle size distribution. However, macropores showed to be also sensitive to soil aggregation rather than properly changes in total soil volume (e.g., degree of compactness).

土壤孔隙在功能上可分为大孔、中孔和微孔。这些孔隙的体积受土壤的本构和状态成分的影响很大，例如粒度分布和密实度。在这项研究中，我们旨在检查土壤质地和紧密度对总孔隙度以及大孔、中孔和微孔分布的影响。在用甘蔗栽培的八种不同质地的土壤中获取未受干扰的土壤核心，并在 - 30 和 - 100 hPa 的基质电位下进行平衡，用于计算大孔（有效孔径 - EPD > 100 µm）、中孔（EPD 100-30 µm）和微孔(EPD < 30 µm)。使用土壤颗粒大小和紧密度的加性样条函数对每个孔隙类别的体积进行建模。还测量了土壤有机碳和土壤团聚体的平均重量直径 (MWD)，以支持这些发现。总孔隙度和大孔取决于密实度和粉砂加粘土含量，而粉砂加粘土含量显着影响中孔和微孔。总孔隙度和大孔隙度随着密实度的增加而降低，主要用于粉砂和粘土含量低于~500 g kg 的土壤^-1 ; 尤其是对于大孔隙，由于这些土壤的 MWD 更高，因此随着淤泥和粘土含量的进一步增加（> 500 g kg ^-1），这些减少显着减少。中孔在淤泥和粘土含量较低的土壤中占主导地位，而在淤泥和粘土含量高于 500 g kg ^{-1 的}土壤中它们的体积几乎为零，仅观察到大孔和微孔。总之，在其大小取决于土壤质地的过程中，紧密度的增加可能会降低总孔隙度和大孔隙度，而中孔和微孔的主要变化仅与粒度分布相关。然而，大孔隙对土壤聚集也很敏感，而不是对土壤总体积的适当变化（例如，紧密度）。