Short-term effects of hedgerow planting on soil water and fertilizer in Taihang Mountain slopes

To explore the effects of biological measures on improving the soil environment of artificial forest slopes, five hedgerows of Lycium chinense Miller, Prunus humilis Bunge, Forsythia suspensa (Thunb.) Vahl, Lonicera japonica Thunb., and Mentha canadensis Linnaeus were set up on typical slopes in the eastern foothills of Taihang Mountains, with blank bare ground in a parallel position taken as the control. The effects of different hedgerows and their belts on surface soil water and fertilizer were analyzed. The results showed that: (1) Among the indicators related to soil water, the natural water content of soil in the upper and middle positions of different hedgerow belts increased by 14.55% to 62.69%, compared with the blank control group. The total soil porosity was higher than that of the blank control group, and the differences between different hedgerows were significant (P<0.05). The soil bulk density of hedgerows decreased significantly compared with the blank control group, and the content of soil clay particles in the upper and middle positions of the belt decreased by 1.25% to 18.56% compared with the blank control group. (2) Among the indicators related to soil fertilizer, the soil organic carbon content of different hedgerows increased by 8.93% to 64.00% compared with the blank control group. The soil carbon-to-nitrogen ratio was significantly higher than that of the blank control group, while the soil pH, conductivity, and total nitrogen content were mainly lower than that of the blank control group. The differences between different hedgerows were significant (P<0.05). (3) The correlation between soil water and fertilizer indicators of each hedgerow was significant, with significant positive and negative correlations observed between soil total nitrogen and electrical conductivity and natural water content, respectively (P<0.05). There were significant positive correlations between soil organic carbon and powder grains (P<0.05), and significant negative correlations between soil organic carbon and total porosity and sand grains (P<0.05). (4) Comprehensive scores of effects on soil water and fertilizer of different hedgerows were as follows: Lonicera japonica Thunb. (1.970)> Mentha canadensis Linnaeus (1.677)> Prunus humilis Bunge (1.670)> Lycium chinense Miller (1.655)> Forsythia suspensa (Thunb.) Vahl (1.643)>blank control group (1.527). All five hedgerows could maintain soil moisture and regulate soil fertilizer in the short term. Lonicera japonica Thunb. exhibited the best soil water and fertilizer regulation effect and could be used to rehabilitate Taihang Mountain slopes with more severe soil erosion.