Objective  Soil macropores are the main channels for soil water and gas migration and exchange. The study on soil macropores and water infiltration is of great significance for exploring the slopes of hilly area with strong spatial and temporal changes in hydrological connectivity, which can provide reference for efficient use of land in the red soil hilly areas.

  Method  In this study, the characteristics of soil macropores and water infiltration of typical land use types on different slope positions in the hilly red soil region of northern Guangdong were quantitatively studied by computerized tomography scanning technique and double-headed infilometer method.

  Result  There are significant differences in soil physicochemical properties for different land use types. The soil bulk density became larger with the increase of soil depth, while the soil organic matter content decreased with the increase of soil depth. Macroporosity, total volume and total surface area of macropores were as follows: forest > orchard > farmland, and the number of macropore was as follows: orchard > forest > farmland, and the number of macropore decreased with the increase of soil depth. The average diameter of macropore was as follows: forest > farmland > orchard, and the macropore diameters in different land use types were mainly 0 ~ 3 mm. The macroporosity was significantly negatively correlated with soil density, and positively correlated with organic matter and sand content. Soil saturated hydraulic conductivity was as follows: orchard > forest > farmland, and soil saturated hydraulic conductivity was influenced by capacity, but also correlated with organic matter content and macropore length.

  Conclusion  The changes in land use types resulted in significant variabilities in soil physicochemical properties such as macroporosity and saturated hydraulic conductivity. The maximum macroporosity and total macroporous surface area were found in forest, while the maximum number of macropore and saturated hydraulic conductivity were found in orchard.