High-energy moisture characteristics of various low organic matter sandy soils in different land uses

•Some soil structural properties like HEMC indices were investigated in various land-uses.•HEMC indices were more sensitive to soil textural properties than soil structure.•Near-saturated moisture and soil water retention indicated soil structural condition.•VDP, SI, SiR, and VDPR were changed by soil texture characteristics.•Mean weight diameter and fractal dimension showed the aggregate stability better. Soil structure serves as one of the most important soil physical properties influencing on water retention, aeration, plant growth as well as environmental conditions. In the current study, the effect of four land-use types on some soil structural stability indices including high-energy moisture characteristic (HEMC) at both fast and slow wetting modes, volume of the drainable pores (VDP), structural index (SI), stability ratio (SR), fractal dimensions (D) and mean weight diameter (MWD) was investigated. Jiroft County, is located in southeastern part of Kerman Province, Iran (28ο40׳ N, 57ο44׳ E) and characterized by soils generally high in sand and low in organic matter (OM) was selected as the study area. Land-use types included disturbed and undisturbed rangelands, protected natural forest and an artificial forest plantation. The HEMC results showed that in the slow wetting mode, undisturbed rangeland (49.6%) and protected natural forest (42.6%) indicated the highest and lowest values for near-saturated water contents, respectively. However, in fast wetting modes no significant differences was observed in case of near-saturated water content between undisturbed rangeland and disturbed rangeland and artificial forest plantation land-uses. Furthermore, the near-saturated water contents in the protected natural forest did not changed for both fast and slow wetting modes. The lowest MWD (0.05 mm) and the highest fractal dimension values (2.97) were observed for protected natural forest. The lowest values for VDP, VDP ratio (VDPR), and SI were found for undisturbed rangeland and disturbed rangeland, with the highest values obtained for protected natural forest. No significant differences were found among the land-use types in terms of SR. Furthermore, soil water retention was also low in the land use types with low aggregate formation agents like clay, OM, and calcium carbonate equivalent (CCE). Among the HEMC indices, near-saturated water content and soil water retention only indicated the structural condition. While other HEMC indices such as VDP, SI, SiR