Distribution characteristics of soil organic carbon and nitrogen in farmland and adjacent natural grassland in Tibet

作     者：Liu Heman Cao Lihua Xu Changchang Yang Hong Li Baoguo 

作者机构：College of Resources and EnvironmentChina Agricultural UniversityBeijing 100093China Research Center of Climate Change and Material Cycle of Pedosphere of Tibet PleateauAgricultural and Animal Husbandry CollegeTibet UniversityLinzhi 860000China 

出 版 物：《International Journal of Agricultural and Biological Engineering》 (国际农业与生物工程学报（英文）)

年 卷 期：2016年第9卷第1期

页      面：135-145页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 090301[农学-土壤学] 

基　　金：The research financial was supported by the National Natural Science Foundations of China(Grant No.41161052,41461054,41561052) the Project of Promote Plan for Ecology Research Team,and the Support Program for the Backbone of the Young Teachers of Agricultural and Animal Husbandry College,Tibet University 

主　　题：Tibet farmland grassland soil organic carbon soil total nitrogen nitrate nitrogen ammonium nitrogen 

摘      要：Land-use significantly affects soil organic carbon(SOC)and nitrogen cycling,eventually leading to global climate *** cold and arid climate conditions in Tibet are not conducive to transformation of SOC and ***,research on SOC and nitrogen distribution under different land-use patterns in Tibet is an important basis to assess the soil carbon and nitrogen potential in the land ecosystem of this *** study aims to explain the effects of two land-use patterns,namely,farmland and grassland,on SOC and nitrogen contents in the cold regions of *** study also seeks to provide a scientific basis for the agricultural and grass production *** achieve these goals,the changing features of total nitrogen(TN),mineralized nitrogen(nitrate nitrogen(NN)and ammonium nitrogen(AN)),and SOC were analyzed in different soil depths(0-5,5-10,10-20,20-30,30-40,and 40-50 cm)in farmland and adjacent natural *** differences in carbon and nitrogen contents between the farmland and grassland of the main agricultural area of Tibet were determined through combined field survey and lab *** showed that the contents of SOC,TN and mineralized nitrogen in the grassland and farmland decreased with increasing soil depth mainly in the surface with depth of 0-20 *** effects of the different land-use patterns on the contents of SOC and TN were primarily evident in the 0-10 cm surface *** contents of SOC and TN in the farmland were significantly lower than those in the grassland,with mean reduction by 28.36%for SOC and 20.76%for *** the soil layer is deeper than 10 cm,the contents of SOC and TN in the farmland were greater than those in the *** finding indicated that the transformation from grassland to farmland in Tibet mainly influenced the SOC and TN in the 0-10 cm surface ***,the results showed that the increment of carbon in the deep soil layers of the farmland partially offsets the SOC loss from the surface becau