短期围栏封育对荒漠草原沙化灰钙土有机碳组分及物理稳定性的影响  

Effects of short-term fencing on organic carbon fractions and physical stability of sandy sierozem in desert steppe of Northwest China

作　　者：杨新国[1] 宋乃平[1] 李学斌[1] 刘秉儒[1] 

机构地区：[1]宁夏大学西北土地退化与生态恢复国家重点实验室培育基地,银川750021

出　　处：《应用生态学报》2012年第12期3325-3330,共6页Chinese Journal of Applied Ecology

基　　金：国家"973"计划前期研究专项(2012CB723206);国家自然科学基金项目(41101301;31140017);宁夏回族自治区自然科学基金项目(NZ1005)资助

摘　　要：以宁夏盐池县荒漠草原5年围栏封育草地(围栏内)和自由放牧草地(围栏外)为对象,分析0～40cm土层土壤有机碳、易氧化有机碳和颗粒有机碳含量以及土壤粒径组成,研究围栏封育早期沙化灰钙土有机碳组分及物理稳定性的变化规律.结果表明:围栏内外土壤有机碳含量和颗粒组成差异不显著;围栏内外0～40cm土层土壤有机碳含量平均为3.25g·kg-1,沙粒、粉粒、黏粒的相对比重平均为72%、16%、12%,土壤物理稳定性指数为1.30%～1.31%.土壤活性有机碳的显著变化集中在10～20cm土层,围栏内易氧化有机碳含量达0.80g·kg-1,显著高于围栏外的0.62g·kg-1,围栏内颗粒有机碳的分配比例为50.9%,显著高于围栏外的31.7%.随土层深度的增加,围栏内0～40cm土壤质地由沙性土向沙壤土转变,各层间土质差异显著,易氧化有机碳含量逐渐升高;而围栏外土壤质地的垂直变化相对平缓,基本为沙性土质.退化荒漠草原短期围栏封育条件下,沙化灰钙土土壤有机碳尚处于一个消耗与积累的平衡阶段,土壤质地状况相对稳定,土壤物理稳定性变化较小.10～20cm土层土壤活性有机碳含量及其相对分配比例可作为围栏封育早期土壤质量变化的指示指标.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 differ- ences were observed in the soil side the fence. The average soil percentages of sand, silt, and out- the 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 0.80g·k^-1 inside the fence, which was significantly higher than that outside the fence （0.62 g·k^-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 graduall the fence was sandy, and its vertical change was relatively smooth. y; while the soil texture outside 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.

关 键 词：荒漠草原 围栏封育 土壤有机碳 沙化灰钙土 

分 类 号：S812[农业科学—草业科学]