Abstract:
The Linze Oasis in the middle of the Hexi Corridor is located on the southwestern edge of the Badain Jaran Desert. A large number of windbreak and sand fixation plants are grown and developed in the desert-oasis transition zone. Taking the soil in the root zone of the three sand-fixing plants of
Haloxylon ammodendron,
Calligonum mongolicum and
Nitraria sphaerocarpa as the research object, the changes of soil physical properties and water-holding performance indices in the root zone of different sand-fixing plants were explored, including their relationships with each other, in order to provide a scientific basis for the selection and spatial configuration of the sand-fixing plants in the practice of sand prevention and control engineering. The results showed that: (1) The soil bulk densities in the root zones of the three sand-fixing plants were decreased with the increase of the soil depth, presenting a mean value order by
Calligonum mongolicum >
Nitraria sphaerocarpa >
Haloxylon ammodendron. The soil porosities in the root zones of the three sand-fixing plants were increased with the increase of soil depth, showing a mean value order by
Haloxylon ammodendron >
Nitraria sphaerocarpa >
Calligonum mongolicum, while the soil physical properties in the root zones of the three sand-fixing plants were increased with the deepening of the soil depth. (2) Within the soil depth of 0-120 cm, the water retention characteristics of the soil in the root zone of
Haloxylon ammodendron was the best, followed by
Nitraria sphaerocarpa, and that of
Calligonum mongolicum was the lowest. There were significant differences in soil water retention characteristics in the root zone between
Haloxylon ammodendron and
Calligonum mongolicum in the soil depth of 40-60 cm, as well as in the soil water retention characteristics of the root zones of the three sand-fixing plants within the soil depth of 60-80 cm. (3) The soil water holding capacities of the root zones of the three sand-fixing plants were significantly correlated with soil bulk density, total porosity and capillary porosity (
P < 0.01), but their correlations with non-capillary porosity was different. Meanwhile, the soil water retention characteristics of
Haloxylon ammodendron root zone was significantly positively correlated with non-capillary porosity (
P < 0.01), whereas there was no significant correlation between soil water retention characteristics and non-capillary porosity in the root zones of
Calligonum mongolicum and
Nitraria sphaerocarpa.