Characteristics of soil porosity and water storage in valley section of Zagunao River basin in the upper reaches of Min River

In this study，the“V” type river valley section formed by Jiuzi village and Sanzhai village of Zagunao River basin in the upper reaches of Min River was selected to study the soil bulk density，soil pore and water storage characteristics and its heterogeneity in the valley cross-section ecological forest. The results showed that soil bulk density in the southern side of river valley was 1.24 g/cm3，less than the value 1.47 g/cm3 in the north side；the variation of surface soil（ 0-15 cm） was large，the maximum difference in the southern side was up to 0.27 g/cm3， the maximum difference in the north side was 0.015 g/cm3，while the variation of subsoil（ 60-75 cm） was small； the soil bulk density decreased with the soil depth and elevation increasing. Soil porosity in the southern side of river valley was 52.51%，higher by 7.3% than the value 45.21% in the north side；and the soil porosity was negatively correlated with soil depth and altitude. Soil water storage in the southern side of river valley was 380.71 mm，larger than that（ 332.70 mm） in the north side；soil water storage depended on soil porosity and was positively correlated with altitude. The results could provide reasonable suggestions for the layout of ecological restoration and conversion of farmland to forest and grassland in the Zagunao River basin.