Background Land desertification has always been a major ecological and environmental problem troubling local people's production and life in the wind-sand and grassy flat area in northern Shaanxi province. How to select trees scientifically after the reasonable mixing of local soft sandstone and aeolian sand soil into soil is still a scientific problem that needs to be further solved. To understand the soil characteristics under different forest cover in the aeolian sand soil remediation area provides the decision basis for tree planting optimization, and has important practical significance for the management and ecological environment restoration of Mu Us Sandy Land.

Methods In this study, in the soft sandstone remediation project area of aeolian sand soil in Mengjiawan village, Yulin city, Shaanxi province, the forest soil of Caragana korshinskii and sea buckthorn of different years with the same topography, geomorphology and site conditions was selected as the research object, and the natural grassland was taken as the reference. Using the method of time generation and space, topsoil samples (0-20 cm) were collected in 5, 10 and 15 years from the forest lands of the first phase (2007), second phase (2012) and third phase (2017), respectively, to measure the soil density, water content, organic matter and calcium carbonate.

Results In the aeolian sandy soil area, the soil bulk density and soil calcium carbonate size of different woodlands were as follows: natural barren grassland > C. korshinskii>Hippophae rhamnoides, among which, the soil bulk density of H. rhamnoides was 3.10% lower than that of C. korshinskii, and 10.04% lower than that of the natural barren grassland. The soil calcium carbonate content of the soil was 13.82% lower than that of C. korshinskii, and 37.66% lower than that of barren grassland. The soil moisture content and soil organic matter of different woodlands were as follows: H. rhamnoides > C. korshinskii > natural barren grassland, among which, the soil moisture content of H. rhamnoides was 21.71% higher than that of C. korshinskii, and 96.68% was relatively larger than that of barren grassland. The soil organic matter content of H. rhamnoides was relatively 9.48% were larger than C. korshinskii, and 55.64% were larger than barren grassland. With the increase of planting years after remediation, the soil bulk density and soil organic matter content of different woodlands increased, the soil moisture content was the largest in 10 years of remediation, while the soil calcium carbonate content decreased with the increase of remediation years.

Conclusions To sum up, through the experimental results of soil characteristics of different forest lands, the problem of tree seed selection after land consolidation in the wind-sand and grass-flat area of northern Shaanxi was solved. The planting of trees has improved the soil structure after the use of feldspathic sandstone to remediate the aeolian sandy soil, among which the planting of H. rhamnoides is suitable.