土地利用对天山北麓土壤盐渍化的影响

通过野外调查和室内分析,研究了新疆三工河流域平原绿洲耕地、人工林地、草地、灌木林地和盐碱地0～20 cm表层土壤盐溃化特征.结果表明:整个农业绿洲土壤盐分含量均值为9.33 g/kg,其中耕地平均值为6.9g/kg,超过75%耕地样点集中分布在低于2 g/kg的区间,而其它土地利用类型均高于10 g/kg,并且样点分散分布于各盐分等级中,自然和人为活动对不同土地利用类型盐分聚积均有显著作用;随地貌单元,自南向北盐分均值含量增加,在冲洪积扇中上部和地下水溢出带,盐分均值低于3.8 g/kg,而在冲洪积平原区,则高于10g/kg;由于区域水资源的南北分布格局与利用差异,使得土壤盐分具有中等或强的空间变异性.

Effects of Land Use Type on Soil Salinization at Northern Slope of Tianshan Mountain

Based on field survey and laboratory analysis, the salt content of surface soils (0- 20 cm) were studied in cropland, planted forest, grassland, shrubbery land, and saline alkali land of the agricultural oasis at the Sangong river catchment of Xinjiang. The result revealed that: the mean value of soil salt content was 9. 33 g/kg in full agricultural oasis, and 6. 9 g/kg in crop land where more than 75% soil sample was concentration in lower than 2 g/kg, but more than 10 g/kg in others land use types where soil samples were decentralization in different salinity class. Accumulation of soil salinity in different land use types was significantly affected by natural processes and human activities. Mean values of soil salinity in different geomorphology zones were increased with the change of geomorphology from south to north, and mean values was lower than 3. 81 g/kg in middle-upper alluvial-proluvial delta and groundwater overflowing belt, but higher than 10 g/kg in alluvial plain. Due to different distribution pattern and utilization of southern and northern water resources, soil salinity had a moderate or great variability.