长期耕作对新疆绿洲农田土壤颗粒中有机碳和全氮含量的影响  

Effects of Long-Term Cultivation on Contents of Organic Carbon and Total Nitrogen in Soil Particulate Fraction in Oasis Farmland of Xinjiang

作　　者：唐光木 张云舒[2] 徐万里[2] 马海刚[2] 胡克林[1] TANG GuangMu;ZHANG YunShu;XU WanLi;MA HaiGang;HU KeLin(College of Land Science and Technology,China Agricultural University,Beijing 100193;Soil Fertilizer and Agricultural Water Saving Research Institute,Xinjiang Academy of Agricultural Sciences,Urumqi 890091)

机构地区：[1]中国农业大学土地科学与技术学院,北京100193 [2]新疆农业科学院土壤肥料与农业节水研究所,乌鲁木齐830091

出　　处：《中国农业科学》2020年第24期5039-5049,I0066,共12页Scientia Agricultura Sinica

基　　金：国家自然科学基金(31660073);天山雪松计划(2017XS08);国家重点研发计划(2017YFD0200803-04)。

摘　　要：【目的】土壤颗粒中有机碳和全氮是土壤有机碳和全氮的重要组成部分,研究长期耕作对农田土壤颗粒组分中有机碳和全氮组分含量和比例变化的影响,有助于揭示不同耕作年限下土壤有机碳和全氮的固存与周转规律,可为区域农田土壤培肥和固碳减排提供科学依据。【方法】以天山南北3个典型绿洲(兰州湾镇、31团、普惠农场)长期耕作农田土壤为研究对象,采用土壤颗粒分级法,研究不同耕作年限(0、5、10、15、20年)下3个典型绿洲农田土壤有机碳和全氮的变化规律,分析长期耕作对不同颗粒组分中有机碳和全氮含量的影响。【结果】(1)长期耕作增加了土壤有机碳和全氮的积累,并随耕作时间的延长而趋于平稳。与未耕作土壤相比,耕作0-5 a间,土壤有机碳、全氮含量增加迅速,兰州湾镇、普惠农场和31团土壤有机碳含量分别提高了76.4%、286.2%和145.6%,土壤全氮含量提高了14.7%、58.9%和75.0%,耕作5 a后,增速趋于平缓。(2)耕作提高了不同颗粒组分中有机碳和全氮含量,砂粒中有机碳含量表现为先增加后下降的趋势,与未耕作土壤相比,兰州湾、31团和普惠农场在耕作10-15 a间达到峰值,随后下降;耕作20 a后土壤砂粒中有机碳含量分别增加了0.63、0.89和1.56 g·kg^-1。而粉粒和黏粒中有机碳含量随耕作时间延长表现为持续增加,耕作20 a后,兰州湾、31团和普惠农场粉粒和黏粒中有机碳含量分别增加了0.42-2.39、2.64-3.39、1.36-2.72 g·kg^-1。耕作年限对不同颗粒组分中全氮含量的影响比较复杂,砂粒中全氮含量表现为随耕作时间呈现逐渐增加的趋势,耕作20 a后,兰州湾、31团和普惠农场砂粒中全氮含量分别增加了0.24、0.40和0.29g·kg^-1;粉粒中全氮含量随耕作时间呈现先下降(0-10 a),而后(10-20 a)上升的趋势,而黏粒中全氮含量则表现为相反的趋势,耕作0-10 a间快速增加,耕作10 a后开始下降。【Objective】Particulate organic carbon and total nitrogen are the important components of soil organic carbon(SOC)and total nitrogen(TN),which has an effect on SOC and TN turnover and sequestration.Therefore,studies exploring the changes in soil particulate organic carbon and total nitrogen under different tillage years could aid the understanding of the mechanism of regional soil carbon and nitrogen fixation,so as to provide a scientific basis for improving land productivity.【Method】In this study,soil samples from the farmlands with different tillage years(0,5,10,15,and 20 years)in the three typical oases(Lanzhouwan,31 corps,and Puhui farms)of Tianshan were collected,and the SOC and TN contents of different particle components were determined.And then,the effects of long-term tillage on SOC and TN contents of different particle components were analyzed.【Result】Results indicated that long-term tillage practices increased SOC and TN accumulation.SOC and TN contents increased rapidly during the first five years of tillage and then tended to be stable after five years of tillage.SOC contents increased to 76.4%(Lanzhouwan),286.2%(31 corps),and 145.6%(Puhui farms)of the SOC contents in uncultivated land.Similarly,TN contents increased to 14.7%,58.9%,and 75.0%,respectively.The effects of long-term tillage practices on OC contents in different particles components were different.The organic carbon(OC)contents in sand showed a downward trend after reaching a maximum value(10-15 years tillage),and then showed a increasing trend,but it remained higher than that of an uncultivated land.After 20 years of tillage,OC contents in sand were increased by 0.63 g·kg^-1(Lanzhouwan),0.89 g·kg^-1(31 corps),and 1.56 g·kg^-1(Puhui farms).While,the contents of OC in silt and clay showed a continuous increasing trend with tillage time,After 20 years of tillage,OC contents in silt and clay were increased by 0.42-2.39 g·kg^-1(Lanzhouwan),2.64-3.39 g·kg^-1(31 corps),and 1.36-2.72 g·kg^-1(Puhui farms).However,the effect of lo

关 键 词：耕作 颗粒组分 碳氮比 有机碳 全氮 绿洲农田 新疆 

分 类 号：S153.6[农业科学—土壤学]