大气CO_(2)浓度与温度升高对小麦表层土壤碳氮含量及酶活性的影响  

Effects of Elevated CO_(2)Concentration and Warming on Carbon and Nitrogen Content and Enzyme Activities in Topsoil of Wheat Field

作　　者：杨琦 邱娜 李露洁 史鑫蕊 张东升 宗毓铮[1,2] 李萍 郝兴宇[1,2] YANG Qi;QIU Na;LI Lujie;SHI Xinrui;ZHANG Dongsheng;ZONG Yuzheng;LI Ping;HAO Xingyu(College of Agriculture,Shanxi Agricultural University,Taigu,Shanxi 030801;Ministerial and Provincial Co-Innovation Centre for Endemic Crops Production with High-Quality and Efficiency in Loess Plateau,Taigu,Shanxi 030801)

机构地区：[1]山西农业大学农学院,山西太谷030801 [2]黄土高原特色作物优质高效生产省部共建协同创新中心,山西太谷030801

出　　处：《核农学报》2023年第10期2088-2098,共11页Journal of Nuclear Agricultural Sciences

基　　金：山西省基础研究计划面上项目(202103021224152);山西农业大学青年拔尖创新人才支持计划(BJRC201602);黄土高原特色作物优质高效生产省部共建协同创新中心基金项目(SBGJXTZX-27)。

摘　　要：为研究大气CO_(2)浓度与温度升高对土壤碳氮元素含量和相关酶活性的影响,以位于山西省临汾市尧都区持续29年定位免耕和旋耕的旱作麦田(111°30′N、36°04′E)0~20 cm表层土为试验材料,在人工气候控制室内设置4个处理:CK(CO_(2)浓度400μmol·mol^(-1),大气温度);eC(CO_(2)浓度600μmol·mol^(-1),大气温度);eT(CO_(2)浓度400μmol·mol^(-1),大气温度+2℃);eCeT(CO_(2)浓度600μmol·mol^(-1),大气温度+2℃)。通过盆栽试验测定小麦关键生育时期土壤有机碳、易氧化有机碳、全氮、硝态氮、铵态氮含量以及相关酶活性。结果表明,持续增温2℃或CO_(2)浓度升高200μmol·mol^(-1)条件下,免耕土壤三个小麦生育时期的易氧化有机碳和硝态氮含量的平均值均较CK降低,降低幅度分别为10.7%~21.3%、7.3%~17.7%,旋耕土壤的易氧化有机碳含量无明显变化,硝态氮含量仅在增温下降低。同时,增温抑制了免耕土壤开花期β-葡萄糖苷酶和β-木糖苷酶活性,CO_(2)浓度升高抑制了免耕土壤开花期和成熟期N-乙酰-β-D-葡萄糖苷酶活性。在CO_(2)浓度与温度升高的叠加作用下,土壤易氧化有机碳和硝态氮含量较CK的下降幅度大于增温单因素处理,降幅分别为26.5%和36.9%;N-乙酰-β-D-葡萄糖苷酶和β-葡萄糖苷酶活性被抑制,旋耕与免耕之间无明显差异;小麦地下部生物量增加,地上部生物量降低;土壤碳库活度降低,总有机碳含量不变。本研究结果为预测未来气候变化条件下北方农田土壤碳氮储量提供了科学依据。In order to investigate effect of elevated atmospheric CO_(2)concentration and warming on soil carbon and nitrogen contents and enzyme activities,a pot trial was performed under elevated CO_(2)(+200μmol·mol^(-1)above ambient CO_(2)),elevated temperature(+2℃above ambient temperature),and their combination at experimental facilities of climate chambers.The soil was taken from 0-20 cm topsoil of a rainfed wheat field(111°30′N,36°04′E)with 29-year no-tillage or rotary tillage measurements located in Yaodu District,Linfen City,Shanxi Province.The contents of soil organic carbon,readily oxidized organic carbon,total nitrogen,nitrate,ammonium and activities of related enzyme were measured.The results showed that elevated CO_(2)and warming treatments decreased readily oxidized organic carbon and nitrate contents by 10.7%-21.3%and 7.3%-17.7%under no-tillage,respectively,while did not change readily oxidized organic carbon content under rotary tillage.Meanwhile,the nitrate content in rotary tillage soil was decreased only under warming condition.Warming inhibited the activities ofβ-glucosidase andβ-xylosidase in no-tillage soil at anthesis stage,and elevated CO_(2)inhibited the activity of N-acetyl-β-d-glucosidase in no-tillage soil at the anthesis stage and maturity stage.The combination treatment of elevated CO_(2)and warming did not change the organic carbon contents,decreased readily oxidized organic carbon and nitrate contents by 26.5%and 36.9%,respectively,inhibited N-acetyl-β-D-glucosidase andβ-glucosidase activities,reduced the carbon pool activity,increased the belowground biomass accumulation,and decreased aboveground biomass accumulation under both tillage practices.This study provides scientific evidences for predicting soil carbon and nitrogen changes under future climate change condition in northern China.

关 键 词：气候变化 土壤有机碳 易氧化有机碳 土壤全氮 土壤酶 

分 类 号：S512.1[农业科学—作物学] S153.6