中文摘要：

通过对不同时期塔里木北部灌区农田样地土壤采样及剖面分析,结合第二次全国土壤普查和塔里木北部灌区相关农业资料,利用Arc GIS软件分析农田土壤有机碳储量和碳密度变化,揭示绿洲化过程中塔里木北部灌区农田土壤有机碳库的演变规律,分析影响土壤有机碳固存的主要因素。结果表明：1灌区不同类型土壤的固碳能力差异显著,有机碳含量从高至低依次为草甸土、盐土、潮土和风沙土;剖面土壤有机碳含量自上而下递减,其中表层土壤有机碳含量高达2~8 g·kg^-1。2剖面0~20 cm和20~40 cm深度的平均土壤有机碳密度分别为（1.36±0.09）kg·m^-2和（1.10±0.07）kg·m^-2,其中风沙土的土壤有机碳密度远低于该区平均水平。3与1981年相比,2011年塔里木北部灌区土壤有机碳密度增量不明显,固碳速率为-0.01~0.03 kg·m^-2·a^-1;不同类型土壤的有机碳密度变化差异显著。总体而言,在绿洲化过程中,新疆塔里木北部灌区的土壤有机碳含量呈增加趋势,土地开发年限及农田管理措施是影响该变化的主要因素。

英文摘要：

Based on analyzing the typical sampling sites in the irrigated area in the north Tarim Basin in different periods and the data from the Second National Soil Survey and agricultural information of this area,the storage and density fluctuation of soil organic carbon content was analyzed by Arc GIS so as to reveal the evolvement of cropland soil organic pools and analyze the relevant affecting factors of soil carbon sequestration in the oasisization process of the irrigated area in the north Tarim Basin. The study was aimed at providing the scientific guidance to improve the soil quality,increase the crop yield in the irrigated area,provide the theoretical support for carbon estimation in Xinjiang and even in north China,and serve for national climate negotiations. The results are as follows： 1 The capacities of carbon sequestration for different soil types in cropland were quite different,and the organic carbon content was in an order of meadow soil 〉solonchak 〉fluvo-aquic soil 〉Aeolian sandy soil. On the scale of soil profile,the organic carbon content was decreased from epipedon to bottom,and that of epipedon was up to 2- 8 g·kg^-1; 2 The average organic carbon densities at depths of 0- 20 cm and 20- 40 cm were（ 1. 36 ± 0. 09） kg·m^-2 and（ 1. 10 ± 0. 07） kg·m^-2respectively,and the organic carbon density for Aeolian sandy soil was much lower than the average; 3 Compared with the 1981 s,the change of soil organic carbon density in the study area in2011 was not significant,and the carbon sequestration rate was in the range of- 0. 01- 0. 03 kg ·m^-2·a^-1.However,there was a remarkable difference of organic carbon density among different soil types. Holistically,the soil organic carbon content in cropland in the region was increased in the oasisization process,and the main factors affecting the change of soil carbon content were the agricultural practices and reclamation duration.