豫东沙土农区杨树-农作物复合生态系统中温室气体排放的研究  

Study on Greenhouse Gas Emissions from Sandy Soil of Eastern Henan with Poplar-Crop Agroforestry System

作　　者：张香凝[1,2] 史福刚 李太魁[1,2] 郭战玲[1,2] 张玉亭 寇长林[1,2] ZHANG Xiang-ning;SHI Fu-gang;LI Tai-kui;GUO Zhan-ling;ZHANG Yu-ting;KOU Chang-lin(Institute of Plant Nutrition,Agricultural Resources and Environmental Sciences,Henan Academy of Agricultural Sciences,Zhengzhou 450002,China;Henan Key Laboratory of Agricultural Eco-environment,Zhengzhou 450002,China)

机构地区：[1]河南省农业科学院植物营养与资源环境研究所,河南郑州450002 [2]河南省农业生态环境重点实验室,河南郑州450002

出　　处：《江西农业学报》2024年第7期62-68,共7页Acta Agriculturae Jiangxi

基　　金：河南省重大科技专项(221100110700);国家重点研发计划(2021YFD1700904-6);河南省科技攻关项目(172102310184);河南省农业科学院自主创新项目(2019ZC31、2021ZC32、2023ZC035)。

摘　　要：为了探讨农林复合系统农田土壤温室气体排放的贡献率,在豫东沙区杨树—农作物复合生态系统中选取了2种典型的防护林网密度——大网格BT(防护林间距1000 m×1000 m)、小网格ST(防护林间距200 m×200 m),并用周边5~10年生的人工纯林地作对照,采用静态箱—气相色谱法对不同防护林网密度的杨树—农作物复合生态系统中土壤温室气体(CO_(2)、N_(2)O、CH_(4))季节排放通量进行田间原位测定。结果表明:豫东农区农田土壤是CO_(2)、N_(2)O的排放源、CH_(4)的吸收汇。不同农林复合模式对土壤温室气体的排放或吸收的强度都有不同的特征,大网格、小网格、林地土壤CO_(2)日排放通量均在7月达到最大值,分别为1163.17、1005.91、923.53 mg/(m^(2)·h);大网格的土壤N_(2)O日排放通量在7月达到最大值,小网格和林地则在8月达到最大值,土壤N_(2)O排放通量为4.29~313.28μg/(m^(2)·h);3种模式下土壤CH_(4)的吸收峰值均在7月达到最大值,其中大网格的吸收峰值最大,为4.41 mg/(m^(2)·h)。不同农林复合经营模式通过影响土壤、空气温度和湿度等来影响农田土壤温室气体排放,其中增温干燥强化了土壤CO_(2)和N_(2)O排放源的特征,但同时也增加了土壤作为大气CH_(4)吸收汇的功能,大网格、小网格、林地的全球增温潜势(GWP)分别为1.50×10^(5)、1.03×10^(5)、0.885×10^(5)kg C/hm^(2),单位面积GWP值以林地的最小、大网格的最大。总的来看,适当增加防护林网密度有利于减少农林系统的增温潜能。In order to study the contribution rate of soil greenhouse gas emission in agroforestry,polar-crop agroforestry systems with two typical densities of shelterbelt(shelterbelt distance with 1000 m×1000 m(BT)and 200 m×200 m(ST)respectively)and 5-10 years old planted forest(CK)were investigated in eastern Henan.The seasonal emission fluxes of soil greenhouse gases(CO_(2),N_(2)O,CH_(4))in poplar-crop agroforestry systems with different densities of shelterbelt were measured in field situ by the static chamber-gas chromatograph method.The results showed that arable land in eastern Henan was the sources of atmospheric CO_(2)and N_(2)O,the sink of atmospheric CH_(4).Different agroforestry composite models have different characteristics on the intensity of soil greenhouse gas emissions or absorption.The flux of CO_(2)of all the treatments reached maximal seasonal emission in July.The values of the flux for the three treatments were 1163.17,1005.91 and 923.53 mg/(m^(2)·h)respectively.Flux of N_(2)O from BT reached maximal seasonal emission in July,but that of ST and the CK in August.N_(2)O emission fluxes varied from 4.29 to 313.28μg/(m^(2)·h).The maximal absorption flux of CH_(4)was in July,the value of BT was the largest,with 4.41 mg/(m^(2)·h).Different agroforestry affect greenhouse gas emissions from farmland soil by affecting farmland microclimate such as soil and air temperature and humidity.Warming and drying enhanced the characteristics of soil CO_(2)and N_(2)O emission,but increased the function of soil as atmospheric CH_(4)absorption sink at the same time.The global warming potential(GWP)of BT,ST and CK was 1.50×10^(5),1.03×10^(5),0.885×10^(5)kg C/hm^(2)respectively.Among all the treatments,the agroforestry with large shelterbelt distance has the biggest global warming potential,but forest has the smallest.Properly increasing the density of shelterbelt is conducive to reducing the GWP of farmland ecosystem.

关 键 词：农林复合经营 温室气体排放 农田防护林网 增温潜势 

分 类 号：S154.1[农业科学—土壤学]