In this study, the maximum soil water holding capacity (MC), capillary water capacity (CC), field capacity (FC), and basic soil physicochemical properties of different soil layers (0-10, 10-20, and 20-30 cm) were measured under three land use patterns of agriculture, forestry, and grassland along a 550 km north-south transect in eastern Qinghai province. Results showed that: (1) the mean MC, CC, and FC at 0-30 cm soil of forestland were 526.83 g·kg-1, 469.75 g·kg-1, and 408.29 g·kg-1, respectively. For grassland, their values were 506.17 g·kg-1, 446.37 g·kg-1, and 384.89 g·kg-1, respectively. All these values were significantly higher than those of farmland (306.62 g·kg-1, 254.25 g·kg-1, and 227.12 g·kg-1, respectively; P< 0.05). (2) The MC, CC, and FC of forestland and grassland decreased gradually as soil depth increased. By comparison, no obvious changes in MC, CC, and FC occurred as soil depth in the farmland increased because of soil compaction. (3) Principal component analysis revealed that soil bulk density, porosity, and soil particle composition cumulatively contributed 79.07%-94.79% to soil water holding capacity (MC, CC, and FC) in the farmland, forestland, and grassland. (4) Redundancy analysis indicated that the explanations of different environmental factors on soil water holding capacity of agriculture, forestry and grassland from large to small are annual evaporation, altitude, annual rainfall and latitude. This study could provide a reference for soil quality evaluation, soil water management, and regulation under different land use types in alpine regions.
