Background The wind-sand area in the northwest of Liaoning Province is located in the northeast of China, which is a typical area with fragile natural environment and frequent wind-sand disasters. In this area, the soil surface is dominated by wind-sand soil, and after rainfall or irrigation, the water quickly moves to the deep soil, which is easy to form soil preferential flow. In-depth analysis of the characteristics of preferential flow under different land use types in the sandy land of northwestern Liaoning has certain practical guiding significance for saving water resources and reducing fertilization input and can also provide a scientific basis for ecological restoration and protection in northwestern Liaoning.

Methods In this study, four typical land use types were selected in the sandy land of northwest Liaoning province, namely, forest land, grassland, garden land and cultivated land. Through the outdoor bright blue staining tracer test, the staining image was analyzed, the soil staining morphological characteristics were analyzed, and the influencing factors of soil priority flow were analyzed by regression analysis combined with the sample data collected by indoor determination. In this study, the sample plots of different land use types in the sandy land of northwest Liaoning were taken as the research objects. Through the outdoor bright blue staining tracer test, the staining images were analyzed, and the morphological characteristics of soil staining were analyzed. Combined with the sample data collected indoors, the regression analysis of the influencing factors of soil preferential flow was carried out.

Results 1) There were differences in soil preferential flow patterns among different land use types. The dyeing image of forest land showed obvious ''S'' type single peak change, the dyeing image of cultivated land had no obvious fluctuation, and the depth of matrix flow was the largest. The development of soil preferential flow in some soil layers of grassland and garden land is obvious. 2) There was a significant correlation between soil preferential flow dyeing area ratio and soil depth, and the goodness of fit of the regression model was high. 3 ) The correlation degree between the influencing factors and the area ratio of soil preferential flow dyeing was root weight density > total porosity > soil bulk density > root length density > capillary porosity.

Conclusions Soil total porosity, capillary porosity, root length density and root weight density can promote the formation and development of soil preferred flow, while soil bulk density can inhibit soil preferred flow in the aeolian sandy land in northwest Liaoning, and the correlation degree is as follows: root weight > total porosity > soil bulk density > root length density > capillary porosity. In the north wind sandy land of western Liaoning province, the priority flow can be adjusted by adjusting these indexes to save water resources and reduce fertilization input.