Background Large-scale vegetation restoration, especially afforestation, has intensified the evapotranspiration process, the deep soil of the Loess Plateau has dried up, and the runoff of the Yellow River has been reduced, and vegetation restoration has approached the threshold of water resources and vegetation carrying capacity. Vegetation restoration may significantly improve soil structure, increase soil water infiltration, and improve soil water holding and storage capacity, which in turn affects changes in basin yield, confluence, and sediment transport. This is of great significance in studying the soil moisture characteristics of natural vegetation restoration and artificial afforestation under specific climatic conditions for soil and water conservation.

Methods Based on the comparison of soil physical and chemical properties and continuous high-resolution water dynamic monitoring, analysis of the water holding capacity and storage capacity of the soil in the Dongzhuanggou(DZG) small basin under natural restoration and the Yangjiagou (YJG) small basin under artificial afforestation.

Results 1) When comparing the DZG small basin with natural vegetation restoration, the soil bulk density and soil porosity of 0-100 cm in the YJG small basin under artificial afforestation and vegetation restorations was 91.9% and 1.1 times that of DZG, respectively. The organic matter content and cation exchange capacity were 21.4% and 22.6% higher than those of DZG, respectively. There was no difference in the physicochemical properties of the topsoil, and the effects of different vegetation restoration methods on the water holding capacity were more profound. 2) Under the same rainfall conditions, the soil moisture content of the DZG 0-80 cm soil layer increased by 8.85% on average, and the total water storage increased by 71.7 mm. YJG 0-80 cm increased by 12.74% on average, and the total water storage increased by 102.1 mm. 3) DZG's soil moisture content responds quickly to rainfall events, while YJG's soil moisture content lags behind the soil depth.

Conclusions After more than 60 years of vegetation restoration at the Xifeng Soil and Water Conservation Test Station in the Loess Plateau and gully region, the soil water-holding capacity of YJG small basin with artificial afforestation is better than that of DZG small basin with natural vegetation restoration.