Soil physical structure plays a crucial role in maintaining grassland ecosystem functions and its formation is intimately linked with plant root systems. However， it remains unclear how different management practices affect soil structure and water retention throughout the profile by regulating belowground biomass （BGB）. This study compared the effects of four management practices—fencing， continuous grazing， rest grazing， and mowing—on soil physical structure （bulk density， pore distribution， aggregate composition）， water retention， and BGB in the 0-10， 10-30， 30-60， and 60-100 cm soil layers. The results showed that the response of soil structure to management was primarily concentrated in the surface layer. In the 0-10 cm layer， continuous grazing significantly reduced BGB， leading to increasing bulk density， decreasing porosity， and a reduction in macroaggregates. In contrast， rest grazing effectively mitigated soil compaction and maintained soil structure by sustaining higher BGB. Macroaggregates were the most sensitive indicator of management， with impacts extending to a depth of 60 cm. Furthermore， both pore structure and water-holding capacity were significantly and positively correlated with BGB. In conclusion， BGB is a key driver of soil structural changes， and rest grazing， by promoting root development， helps to enhance soil structural stability and water storage capacity.

Grassland management  /  Belowground biomass  /  Soil physical structure  /  Water retention  /  Profile differentiation  /  Temperate meadow steppe