Yang Xin-Guo, Song Nai-Ping, Li Xue-Bin, Liu Bing-Ru
State Key Laboratory Breeding Base of Northwest Land Degradation and Restoration, Ningxia University, Yinchuan 750021, China
Ying Yong Sheng Tai Xue Bao. 2012 Dec;23(12):3325-30.
In order to explore the change patterns of organic carbon fractions and physical stability of sandy sierozem in desert steppe at the early stage of fencing, 0-40 cm soil samples were collected from a 5-year fenced desert steppe (inside the fence) and a free grazing steppe (outside the fence) in Yanchi County of Ningxia, Northwest China, with the soil organic carbon, labile organic carbon, and particulate organic carbon contents and soil particle composition analyzed. No significant differences were observed in the soil organic carbon content and soil particle composition inside and outside the fence. The average soil organic carbon inside and outside the fences was 3.25 g x kg(-1), the percentages of sand, silt, and clay were averagely 72%, 16%, and 12%, respectively, and the soil physical stability index was 1.30% -1.31%. The soil active organic carbon showed a significant change in 10-20 cm layer. The soil labile organic carbon content was 0.80 g x kg(-1) inside the fence, which was significantly higher than that outside the fence (0.62 g x kg(-1)). The percentage of soil particulate organic carbon was 50.9% inside the fence, which was also significantly higher than that outside the fence (31.7%). The soil texture inside the fence changed from sandy to loam, and the soil labile organic carbon content increased gradually; while the soil texture outside the fence was sandy, and its vertical change was relatively smooth. The organic carbon of sandy si- erozem in the desert steppe under the conditions of short-term fencing was still in a balance between consumption and accumulation, the soil texture was relatively stable, and the soil physical stability changed little. It was suggested that the soil active organic carbon content and its relative percentage in 10-20 cm layer could be used as the indicators of early soil quality change of desert steppe.
为探究荒漠草原封育初期风沙土有机碳组分及物理稳定性的变化规律，在中国西北宁夏盐池县选取5年封育荒漠草原（围栏内）和自由放牧草原（围栏外），采集0 - 40 cm土壤样品，分析土壤有机碳、活性有机碳、颗粒有机碳含量及土壤颗粒组成。围栏内外土壤有机碳含量和土壤颗粒组成无显著差异。围栏内外土壤有机碳平均含量为3.25 g·kg⁻¹，砂、粉砂和黏粒平均占比分别为７２％、１６％和１２％，土壤物理稳定性指数为1.30％ - 1.31％。土壤活性有机碳在10 - 20 cm土层变化显著。围栏内土壤活性有机碳含量为0.80 g·kg⁻¹，显著高于围栏外（0.62 g·kg⁻¹）。围栏内土壤颗粒有机碳占比为50.9％，也显著高于围栏外（31.7％）。围栏内土壤质地由砂质变为壤质，土壤活性有机碳含量逐渐增加；围栏外土壤质地为砂质，垂直变化相对平缓。短期封育条件下荒漠草原风沙土有机碳仍处于消耗与积累的平衡状态，土壤质地相对稳定，土壤物理稳定性变化较小。建议将10 - 20 cm土层土壤活性有机碳含量及其相对占比作为荒漠草原土壤质量早期变化的指标。
