荒漠地区土地开垦对土壤团聚体稳定性及碳固定的影响

目的]研究土地开垦前后土地利用方式对该地区土壤团聚体稳定性及有机碳的响应机制，为艾比湖湿地保护区的荒地开垦和植被恢复及农业生产提供科学理论依据。方法]选取新疆艾比湖流域未开垦的天然林地(CK)和开垦后人工种植的枸杞地、葡萄地、棉花地、苜蓿地共5种不同土地利用类型下，探究荒漠生态系统土地开垦后的土壤结构和有机碳含量的变化规律。结果]荒漠地区土地开垦对土壤团聚体稳定性及碳固定有显著的影响。土地开垦后，人工种植地块大团聚体(>0.25 mm)含量和团聚体稳定性均显著高于CK,其中棉花地力稳性大团聚体含量最高(>87%);枸杞地水稳性大团聚体含量最高(>79.7%),不同人工耕作模式均增加了大团聚体含量。0—30 cm土层人工种植地块不同团聚体粒级有机碳含量分别为5.91～15.46,5.50～10.70,8.12～16.11,6.90～13.67 g/kg,均显著高于CK(3.91～8.73 g/kg),主要分布在0.25～0.5 mm粒级，各人工土地利用方式下土壤团聚体有机碳含量均显著增加，且枸杞地有机碳含量增加最显著。结论]该区域土地开垦后种植枸杞的耕作模式更有...

Effects of Desert Land Cultivation on Soil Aggregate Stability and Carbon Fixation

Objective] The response of soil aggregate stability and organic carbon before and after land reclamation using different land use types were analyzed in order to provide a scientific theoretical basis for wasteland reclamation, vegetation restoration, and agricultural production in the Ebinur Lake Wetland Reserve.Methods] Five different land use types in the Ebinur Lake basin of Xinjiang were evaluated in this study:uncultivated natural forest land (CK), cultivated artificially planted lycium land, vitis land, cotton land, and alfalfa land. These land use types were selected to determine the response of soil structure and organic carbon content after land cultivation in a desert ecosystem.Results] Land cultivation had significant effects on soil aggregate stability and carbon fixation in a desert area. After land cultivation, the content of macro aggregates (>0.25 mm) and the stability of aggregates of cultivated lands were significantly greater than those of CK. Cotton land had the highest content of force-stabilized macro aggregates (>87%). Lycium land had the highest content of water-stabilized macro aggregates (>79.7%). Different artificial tillage practices increased the content of macro aggregates. The particle size organic carbon contents in the aggregates of cultivated lands in the 0-30 cm soil layer were 5.91-15.46, 5.50-10.70, 8.12-16.11, and 6.90-13.67 g/kg, respectively. These values were significantly greater than the contents observed for CK (3.91-8.73 g/kg), mainly distributed in the 0.25-0.5 mm particle size. The organic carbon contents of soil aggregates increased significantly under all artificial land use practices, and the lycium land organic carbon content increased most significantly.Conclusion] The cultivation practice of planting lycium barbarum after land cultivation was more conducive to increasing soil aggregate stability and improving organic carbon fixation than the other cultivation practices. Land cultivation can significantly increase soil carbon sequestration capacity and improve soil structure.