Changes in land use type can lead to variations in soil water characteristics. The objective of this study was to identify the responses of soil water holding capacity (SWHC) and soil water availability (SWA) to land use type (grassland, shrubland and forestland). The soil water characteristic curve describes the relationship between gravimetric water content and soil suction. We measured the soil water characteristic parameters representing SWHC and SWA, which we derived from soil water characteristic curves, in the 0–50 cm soil layer at sites representing three land use types in the Ziwuling forest region, located in the central part of the Loess Plateau, China. Our results showed that the SWHC was higher at the woodland site than the grassland and shrubland, and there was no significant difference between the latter two sites, the trend of SWA was similar to the SWHC. From grassland to woodland, the soil physical properties in the 0–50 cm soil layer partially improved, BD was significantly higher at the grassland site than at the shrubland and woodland sites, the clay and silt contents decreased significantly from grassland to shrubland to woodland and sand content showed the opposite pattern, the soil porosity was higher in the shrubland and woodland than that in the grassland, the soil physical properties across the 0–50 cm soil layer improved. Soil texture, porosity and bulk density were the key factors affecting SWHC and SWA. The results of this study provide insight into the effects of vegetation restoration on local hydrological resources and can inform soil water management and land use planning on the Chinese Loess Plateau.

In recent years, Sweet Cherry (Prunus avium L.) have been in high demand and planted in large quantities due to their nutritional value and appealing organoleptic properties. The management mode and species characteristics in the tillage process lead to a decrease in soil quality, and the stability of soil aggregates and decrease in soil nutrients indicate this. However, the effects of different sweet cherry varieties and increasing planting ages on soil quality remain unknown. In this study, soil samples were quantitatively analyzed at different soil depths (0-20 cm, 20-40 cm, 40-60 cm) in cheery orchards of different varieties and ages. The results demonstrated that the particle size content of soil aggregates differed among the varieties of sweet cherry in different soil layers. The mechanical stability of soil aggregates was found to be the lowest in Jimei cherry orchard, where the mass ratio of aggregates with particle sizes exceeding 0.25 mm (R > 0.25) was below the highest 20.99 %, geometric mean diameter (GMD) was below 22.52 %, and mean weight diameter (MWD) was below 17.46 %. In contrast, lower ages demonstrated superior performance in aggregate water stability. The stability of soil aggregates was found to be affected by sweet cherry cultivation, with changes observed in the content of SOC and TN in the surface soil. Principal component analysis indicated that soil quality deteriorated increasingly with ages, while pass-through analysis demonstrated that ages and soil aggregate stability were key factors influencing soil quality. In conclusion, in addition to economic benefits, soil quality should also be protected. This study can help to improve the scientific theoretical basis for the introduction of sweet cherry planting on the Loess Plateau and the management of soil quality.

Some newly cultivated land formed by “ditch and make land” on the Loess Plateau has poor soil nutrient, low fertility and unsustainable development. Medicago falcata L. and Arena sativa L. were selected as experimental subjects to investigate the effects of different greening plants on the nutrients of newly cultivated land, providing a theoretical reference for the improvement of soil nutrients in newly cultivated lands on the Loess Plateau. The results showed that in the initial stage of planting grasses on newly cultivated land, within the 0–60 cm soil layer, the soil organic matter, total nitrogen, total phosphorus and alkali-hydrolyzed nitrogen contents of alfalfa and oatgrass increased with the increase of soil depth; the soil total potassium, available potassium and available phosphorus of alfalfa and oatgrass did not change clearly with the increase of soil depth. The soil nutrient indexes of alfalfa and oatgrass were analyzed by principal component analysis, in the short-term comprehensive effect of grasses on soil nutrient improvement was alfalfa > oatgrass. Planting alfalfa can improve the soil nutrient status in newly cultivated land in a short time.