祁连山浅山区退耕地土壤团聚体及其有机碳和全氮的分布特征  

Distribution Characteristics of Soil Aggregate,Organic Carbon and Total Nitrogen in Returned Farmland in Shallow Qilian Mountains

作　　者：董彦丽 李泽霞 高金芳 张峰 王亚竹[2] 王彦武 Dong Yanli;Li Zexia;Gao Jinfang;Zhang Feng;Wang Yazhu;Wang Yanwu(Institute of Soil and Water Conservation of Gansu Province,Lanzhou,Gansu 730020,China;Gansu Research Institute for Water Conservancy,Lanzhou,Gansu 730000,China)

机构地区：[1]甘肃省水土保持科学研究所,甘肃兰州730020 [2]甘肃省水利科学研究院,甘肃兰州730000

出　　处：《水土保持通报》2020年第4期60-66,共7页Bulletin of Soil and Water Conservation

基　　金：国家重点研发计划项目“西北内陆区保水节水技术集成与应用”(2017YFC0404304);甘肃省科技计划项目(18YF1FA032);甘肃省水利科学试验研究及技术推广计划项目(甘水科外发2017-76-2)。

摘　　要：[目的]分析祁连山浅山区退耕地土壤团聚体及其有机碳和全氮分布特征,为该区退耕地植被恢复及水土流失防治提供理论依据。[方法]以祁连山大黄山林区三种类型退耕地为研究对象,通过干筛法测定团聚体粒径,分析不同粒级团聚体组成及其有机碳和全氮分布规律。[结果]3种类型退耕地≥0.25 mm的大团聚体含量高于<0.25 mm的微团聚体,其中以>5 mm和0.25~2 mm粒级团聚体为主;封育草地团聚体稳定性最强,平均重量直径(MWD)高于沙棘林地9.31%,高于未封育草地31.95%;未封育草地土壤有机碳含量低于沙棘林地和封育草地,且差异显著,三种类型退耕地土壤全氮含量没有明显变化趋势;0.25~2 mm团聚体有机碳含量最高,<0.25 mm微团聚体全氮含量最高,沙棘林地和封育草地土壤团聚体养分优于未封育草地;与团聚体分布特征相同,>5 mm和0.25~2 mm粒级团聚体依然是退耕地有机碳和全氮储存的主体。[结论]祁连山浅山区退耕地以≥0.25 mm的大团聚体为主,沙棘林地和封育草地团聚体稳定性及其有机碳和全氮含量高于未封育草地。[Objective]Distribution characteristics of soil aggregate,organic carbon and total nitrogen in returned farmland in shallow Qilian Mountains were analyzed in order to provide theoretical basis for vegetation restoration and soil erosion control in this area.[Methods]Three types of returned farmland in forest region of Dahuang Mountain were taken as the research object,soil aggregate composition were measured by dry sieving method,and the distribute of aggregates,organic carbon and total nitrogen in different level were analyzed.[Results]The content of≥0.25 mm macro-aggregates were higher than aggregates with diameter<0.25 mm,among which,aggregates with dimeter>5 mm and 0.25~2 mm were the main part of aggregates.The stability of the aggregate in closed grassland was the strongest,and its MWD was 9.31%higher than that of seabuckthorn forest and 31.95%higher than that of unclosed grassland.The soil organic carbon content of unclosed grassland was lower than that of seabuckthorn forest and closed grassland,and the difference was significant.There was no significant change of total nitrogen content among the three types of returned farmland.The content of organic carbon was the highest in 0.25~2 mm aggregate,and the content of total nitrogen was the highest in<0.25 mm macro-aggregates.The nutrients of soil aggregates in seabuckthorn forest and enclosed grassland were better than that in unenclosed grassland,>5 mm and 0.25~2 mm aggregates were still the main storage parts of organic carbon and total nitrogen in the returned farmland.[Conclusion]In shallow Qilian Mountains,≥0.25 mm macro-aggregates were the main part.Aggregates stability,organic carbon and total nitrogen of the seabuckthorn forest and closed grassland were higher than that in the unclosed grassland.

关 键 词：祁连山浅山区 退耕地 土壤团聚体 有机碳 全氮 

分 类 号：S152.4[农业科学—土壤学]