怀豆和黑麦草绿肥残体还田对旱地土壤温室气体排放的影响  

Effects of returning green manure residues of vetch and ryegrass on greenhouse gas emission in dryland soil

作　　者：谈光野 IHSAN Muhammad 杨彩迪 王俊 TAN Guangye;IHSAN Muhammad;YANG Caidi;WANG Jun(College of Urban and Environment Science,Northwest University,Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity,Xi’an,Shaanxi 710127,China;Shaanxi Key Laboratory of Carbon Neutral Technology,Xi’an,Shaanxi 710127,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,Shaanxi 712100,China)

机构地区：[1]西北大学城市与环境学院/陕西省地表系统与环境承载力重点实验室,陕西西安710127 [2]陕西省碳中和技术重点实验室,陕西西安710127 [3]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《干旱地区农业研究》2024年第2期245-253,263,共10页Agricultural Research in the Arid Areas

基　　金：国家自然科学基金(42277322,31570440);陕西省农业科技创新驱动项目(NYKJ-2021-XA-005,NYKJ-2022-XA-004)。

摘　　要：以怀豆和黑麦草两种绿肥为对象,分别进行了为期63 d的不同绿肥残体还田量和残体混合比例室内培养试验,其中绿肥残体还田量试验分别设0、1、2、4、6 t·hm^(-2)共5个水平;残体混合比例试验设100%怀豆、25%怀豆+75%黑麦草、50%怀豆+50%黑麦草、75%怀豆+25%黑麦草和100%黑麦草共5个处理,还田量均为4 t·hm^(-2)。采用气相色谱法观测了培养期间土壤温室气体(CO_(2)、N_(2) O、CH_(4))通量变化。结果表明:(1)与未添加绿肥残体相比,绿肥残体还田土壤CO_(2)累积排放通量提高了11.3%~80.2%,土壤N_(2) O排放提高了15.8%~51.1%,综合增温潜势(GWP)提高了11.9%~79.4%(P<0.05)。随绿肥残体还田量的增加,土壤CO_(2)排放通量和综合增温潜势(GWP)均呈线性增加,土壤CH_(4)吸收通量则呈线性下降趋势,而土壤N_(2) O排放通量呈现先增后减趋势,并在还田量约为3 t·hm^(-2)时达到最大。相同还田量下添加黑麦草残体较怀豆残体具有更高的土壤CO_(2)排放和CH_(4)吸收,而添加怀豆残体较黑麦草残体显著促进了土壤N_(2) O排放;(2)土壤温室气体累计通量与绿肥残体混合物中黑麦草比例存在线性相关,随黑麦草添加比例的提高,土壤CO_(2)排放通量显著增加了5.8%~19.7%(P<0.05),GWP显著增加了5.3%~17.7%(P<0.05),而N_(2) O排放通量显著下降了11.2%~41.5%(P<0.05),CH_(4)吸收通量则显著下降了13.4%~50.9%(P<0.05)。综合来看,选择非豆科作物比例较低的绿肥残体,并以较低生物量进行还田,能在保持低GWP的同时获得生态效益。Using vetch and ryegrass residues as green manures,two 63 d incubation experiments were conducted to test the impacts of green manure application rate(0,1,2,4,6 t·hm^(-2))and the residual mix ratio(100%vetch,75%vetch+25%ryegrass,50%vetch+50%ryegrass,25%vetch+75%ryegrass,and 100%ryegrass at a rate of 4 t·hm^(-2))on soil CO_(2),N_(2) O,and CH_(4) emissions.Soil green gas emissions were measured using a gas chromatography.The results indicate that:(1)Compared to the control without green manure,application of green manure significantly increased the accumulative emissions of CO_(2) and N_(2) O and global warming potential(GWP)by 11.3%~80.2%,15.8%~51.1%,and 11.9%~79.4%(P<0.05),respectively.Soil CO_(2) and GWP increased,but CH_(4) uptake decreased linearly with the increase of application rates.However,soil N_(2) O emission varied in a polynomial way with the increase of application rates and peaked at the rate of around 3 t·hm^(-2).At the same rate,application of ryegrass residue had a greater CO_(2) emission and CH_(4) uptake,while a lower N_(2) O emission than that of vetch residue;(2)Soil greenhouse gas emissions were also correlated with the proportion of ryegrass residues in the mixture with vetch residues.Soil CO_(2) emission and GWP increased by 5.8%~19.7%(P<0.05)and 5.3%~17.7%(P<0.05),while N_(2) O emission and CH_(4) uptake decreased with the increases of ryegrass residues in the mixture by 11.2%~41.5%(P<0.05)and 13.4%~50.9%(P<0.05).Overall,selecting green manure residues with a lower proportion of non-leguminous crops and returning them to the field with lower biomass could achieve ecological benefits while maintaining low GWP.

关 键 词：怀豆 黑麦草 绿肥残体还田 温室气体排放 综合增温潜势 

分 类 号：S142[农业科学—肥料学] S147.34[农业科学—农业基础科学] S152.8