ABSTRACT

Soil degradation poses serious environmental problems and requires quantitative assessment. This study aimed to investigate the soil properties in rangelands with different management conditions. Based on the assessment of soil erosion, vegetation cover, vegetation composition, and vegetation vigor, 56 sites were selected in rangelands with moderate, poor, and very poor conditions located in 15 grazing-free areas and one wildlife refuge region. Soil samples (0–10 cm layer) were collected from these sites through a systematic-random method to compare their physical and chemical properties. Results showed that soil organic carbon (OC) and total nitrogen content were significantly different between sites with different range conditions. The mean weight diameter of water-stable aggregates and structural stability index in moderate rangelands were 1.56 mm and 3.98%, respectively, and declined towards more degraded rangeland (i.e. 0.84 mm and 0.83%). Grazing-free rangelands exhibited a relatively larger OC deficit; hence specific management measures and control of grazing are required to enhance the quality of soil in these sites. This study highlighted the role of organic matter in preserving soil structural stability. Increasing protection level of rangelands and decreasing grazing pressure may preserve soil quality and combat desertification in these arid regions.

摘要

土壤退化会带来严重的环境问题，需要进行定量评估。本研究旨在调查不同管理条件下牧场的土壤特性。根据对土壤侵蚀、植被覆盖、植被组成和植被活力的评估，在 15 个无放牧区和 1 个野生动物保护区的中度、差和非常差条件的牧场中选择了 56 个站点。通过系统随机方法从这些地点收集土壤样品（0-10 厘米层），以比较它们的物理和化学性质。结果表明，不同范围条件的样地间土壤有机碳（OC）和全氮含量存在显着差异。中度牧场水稳性团聚体的平均重量直径和结构稳定性指数均为1。分别为 56 毫米和 3.98%，并向更退化的牧场下降（即 0.84 毫米和 0.83%）。无放牧牧场表现出相对较大的有机碳赤字；因此，需要采取具体的管理措施和控制放牧，以提高这些地点的土壤质量。这项研究强调了有机质在保持土壤结构稳定性方面的作用。提高牧场保护水平和降低放牧压力可以保护这些干旱地区的土壤质量和防治荒漠化。这项研究强调了有机质在保持土壤结构稳定性方面的作用。提高牧场保护水平和降低放牧压力可以保护这些干旱地区的土壤质量和防治荒漠化。这项研究强调了有机质在保持土壤结构稳定性方面的作用。提高牧场保护水平和降低放牧压力可以保护这些干旱地区的土壤质量和防治荒漠化。