黄土丘陵区不同土地利用方式下土壤养分及生态化学计量特征  

Soil Nutrients and Ecological Stoichiometry Characteristics Under Different Land Use Patterns in Loess Hilly Area

作　　者：夏光辉 郭青霞[1] 卢庆民 杜轶[1] 康庆 Xia Guanghui;Guo Qingxia;Lu Qingmin;Du Yi;Kang Qing(College of Resources and Environment,Shanxi Agricultural University,Taigu,Shanxi 030801,China;Water Resources Bureau of Yonghe County,Shanxi Province,Yonghe,Shanxi 041400,China)

机构地区：[1]山西农业大学资源环境学院,山西太谷030800 [2]山西省永和县水利局,山西永和041400

出　　处：《水土保持通报》2020年第2期140-147,153,共9页Bulletin of Soil and Water Conservation

基　　金：山西省社会科学基金项目“乡村振兴背景下退耕还林可持续生态补偿研究:以岔口小流域为例”(2019B435);国家自然科学基金项目(41071345)。

摘　　要：[目的]探究黄土丘陵区土地利用方式变化前后土壤养分及生态化学计量比的变化特征,为该区农业生产以及生态恢复工作提供科学依据。[方法]选取山西省永和县岔口小流域因生态工程的实施而改变土地利用方式的坡改梯地(梯田)、退耕还林地(林地)、地埂核桃园地(园地)3种样地为研究对象,以现有坡耕地为对照,利用时空互代法,比较不同土地利用方式变化前后0-20 cm,20-40 cm土壤C,N,P,K含量以及生态化学计量比的差异。[结果]①流域各种生态恢复措施实施后,土壤C,N元素含量明显增加,梯田、林地、园地0-40 cm土壤有机C含量分别是坡耕地的1.38,2.44和1.09倍,全N含量分别是坡耕地的1.76,2.66,1.68倍。P,K元素增加量不明显,林地相比其他2种土地利用方式对C,N元素的固持更加明显;②通过分析土壤养分化学计量比的关系,发现流域土壤的限制性元素为C,N元素;③流域土壤养分及计量比之间存在着稳定的耦合关系,C-N之间的耦合关系最为显著且在各元素和生态化学计量比稳定方面发挥着重要作用。[结论]流域3种土地利用方式有效地改变了土壤全量养分含量和元素的生态化学计量比,有利于流域的生态保护和植被修复。[Objective]The change characteristics of soil nutrients and ecological stoichiometry ratio before and after the change of land use pattern were explored,in order to provide scientific basis for agricultural production and ecological restorations in loess hilly area.[Methods]Three kinds of sample plots,namely,conversion of slope cropland to level terrace(terrace),return the grain plots to forestry(forest land)and terrace walnut garden(garden),were selected as research objects in Chakou small watershed in Yonghe County of Shaanxi Province.Taking the existing slope cropland as the reference substance,the spatio-temporal contrast method was used to compare the contents of C,N,P,K and ecological stoichiometry ratio of 0-20 cm and 20-40 cm soil before and after the change of land use patterns.[Results]①After the implementation of various ecological restoration measures,the content of soil C and N elements increased significantly.The soil organic C content of 0-40 cm in terrace,forest land and garden land was 1.38,2.44 and 1.09 times of that in the slope cropland,and the TN content was 1.76,2.66 and 1.68 times of that in sloping land,respectively.The increment of P and K elements was not obvious,and the forest land immobilized C and N elements were more obviously than the other two modes of land use.②The limiting elements of the soil were C and N through the analysis of ecological stoichiometry ratio of soil nutrients.③There was a stable coupling relationship between soil nutrients and ecological stoichiometry ratio of the watershed,and the coupling relationship between C and N was the most significant and played an important role in the stability between each element and the ecological stoichiometry ratio.[Conclusion]The three land use patterns effectively changed the total nutrient content of soil and the ecological stoichiometry ratio,which was beneficial to the ecological protection and vegetation restoration in the watershed.

关 键 词：黄土丘陵区 土壤养分 生态化学计量 生态恢复措施 

分 类 号：S812.2[农业科学—草业科学] S158.3[农业科学—畜牧学]