荒漠草原区不同植被恢复模式下土壤可溶性氮组分特征

Effects of Four Different Vegetation Restoration Patterns on Characteristics of Soil Soluble Nitrogen Components in Steppe Area

以未平茬人工中间锦鸡儿林地、平茬人工中间锦鸡儿林地、天然草地和天然中间锦鸡儿林地为对象,分别测定各类样地0~5cm、5~10cm、10~20cm及20~40cm土层可溶性氮组分含量并分析其含量特征、垂直分布规律及与土壤有机质、全氮、微生物量碳氮含量之间的关系。结果表明:不同植被恢复样地0~40cm土层土壤氮素含量差异显著(P<0.05),其中20~40cm土层差异显著(P<0.05),土壤氮素的矿化效果为人工中间锦鸡儿林地>天然中间锦鸡儿林地>天然草地>平茬人工中间锦鸡儿林地;不同植被恢复模式下0~40cm土层氮素的有效性无显著差异,但在5~10cm、10~20cm、20~40cm土层有极显著差异(P<0.01),土壤氮素的有效性表现为:人工中间锦鸡儿林地>天然中间锦鸡儿林地>平茬人工中间锦鸡儿林地>天然草地;表明人工栽植中间锦鸡儿可以有效提升土壤氮素的转化和利用效率。

In order to research the characteristics of soil soluble nitrogen components under different vegetation restoration patterns of desert steppe region in Ningxia.The artificial Caragana intermedia forest land (ACI),the pruned artificial Caragana intermedia forest land(PACI),the natural grassland (NG) and the natural Caragana intermedia forest land (NCI) were studied,the content of soluble nitrogen components in 0~5cm,5~10cm,10~20cm and 20~40cm soil layers of the above four types of plots were determined,and the content characteristics,vertical distribution and relationship with soil organic matter,total nitrogen and microbial biomass carbon and nitrogen were analyzed.The results showed:(1) The soil total nitrogen content of 0~40cm soil layer under different vegetation restoration patterns had significant differences (P<0.01),the mineralization effects of soil nitrogen under different vegetation restoration patterns were ACI>NCI>NG>PACI.(2) The soil nitrogen availabilities of 0~40cm soil layer under different vegetation restoration patterns had no significant differences,but there were significant differences between different vegetation restoration patterns of 5~10cm,10~20cm,and 20~40cm soil layers (P<0.01).The soil nitrogen availabilities under different vegetation restoration patterns were ACI>NCI>PACI>NG.(3) Planting artificial Caragana intermedia could effectively improve the transformation and utilization efficiency of soil nitrogen.