摘要
[目的]探究保护性耕作对陇中黄土高原半干旱地区旱作农田土壤二氧化碳(CO_(2))和甲烷(CH_(4))排放的影响,阐明两者的排放特征及主要影响因素,为区域农业生态可持续发展和制定有效的增产减排政策提供科学参考。[方法]以传统耕作(CT)为对照,布设免耕(NT)、传统耕作+秸秆覆盖(CTS),免耕+秸秆覆盖(NTS)3种保护性耕作措施,利用静态暗箱—气相色谱法测定旱作春小麦农田土壤CO_(2)和CH_(4)排放通量,同时对土壤理化性质和小麦产量进行同期测定。[结果]①与CT处理相比,NT,NTS和CTS处理的CO_(2)累积排放量分别减少17.34%,15.67%和1.52%;CH_(4)累积吸收量分别提高11.95%,16.26%和0.16%;全球增温潜势(GWP)分别减少17.66%,16.01%和1.5%;温室气体排放强度(GHGI)分别降低38.15%,45.15%和24.98%。②各处理的土壤有机碳(SOC)和微生物量碳(MBC)含量随土层的加深呈减少趋势;在0—40 cm土层,NT,NTS和CTS处理的SOC和MBC含量均高于CT处理。③相关性分析表明,土壤温度和SOC与CO_(2)排放通量呈极显著正相关(p<0.001),与CH_(4)吸收通量呈极显著负相关(p<0.001);而土壤含水量与CO_(2)排放通量呈极显著负相关(p<0.001),与CH_(4)吸收通量呈极显著正相关(p<0.001)。冗余分析结果则显示,土壤含水量、土壤温度和SOC是影响土壤碳通量的关键因素,其中土壤含水量最为重要。[结论]保护性耕作能够减缓研究地区旱作农田土壤温室气体排放,降低其对温室效应的贡献,同时显著增加小麦产量。综合生态效益与经济效益来看,可以优先考虑将免耕与秸秆覆盖相结合作为该地区农田实现增产减排的耕作措施。
[Objective]The effects of conservation tillage on the emissions of carbon dioxide(CO_(2))and methane(CH_(4))from dryland farming in the semi-arid region of the Loess Plateau in central Gansu Province were investigated and the characteristics of the emissions and the main factors affecting them were elucidated to provide a scientific reference for the sustainable development of regional agricultural ecology and to formulate effective policies for increasing production and reducing emissions.[Methods]Using traditional tillage(CT)as a control,three conservation tillage measures were implemented:no-tillage(NT),conventional tillage plus straw mulching(CTS),and no-tillage plus straw mulching(NTS).Static chamber gas chromatography was employed to measure the CO_(2)and CH_(4) emission fluxes from the soil of dryland spring wheat fields while simultaneously determining the soil physicochemical properties and wheat yield.[Results]①Compared with CT treatment,the cumulative CO_(2)emissions of NT,NTS,and CTS treatments were 17.34%,15.67%,and 1.52%lower,respectively.Cumulative CH_(4) absorption increased by 11.95%,16.26%,and 0.16%,respectively.Global warming potential(GWP)was reduced by 17.66%,16.01%,and 1.5%,whereas greenhouse gas emission intensity(GHGI)decreased by 38.15%,45.15%,and 24.98%,respectively.②The soil organic carbon(SOC)and microbial mass carbon(MBC)decreased with increasing soil depth across all treatments.In the 0—40 cm soil layer,the SOC and MBC contents in the NT,NTS,and CTS treatments were higher than those in the CT treatment.③Correlation analysis showed that soil temperature and SOC had a highly significant positive correlation with CO_(2)emission flux(p<0.001)and a highly significant negative correlation with CH_(4) absorption flux(p<0.001).In contrast,soil moisture was highly negatively correlated with CO_(2)emission flux(p<0.001)and strongly positively correlated with CH_(4) absorption flux(p<0.001).Redundancy analysis showed that soil water content,soil temperature,and SOC were key factors affecting soil carbon fluxes,with soil moisture content being the most important.[Conclusion]Conservation tillage can slow greenhouse gas emissions from the soil of dryland farms in the study area,reduce its contribution to the greenhouse effect,and significantly increase wheat yields.Combining both ecological and economic benefits,the combination of NTS can be prioritized as a tillage measure to increase yield and reduce emissions from farmlands in this region.
作者
廖名燊
李广
姚瑶
杜梦寅
李艳艳
杜俊
Liao Mingshen;Li Guang;Yao Yao;Du Mengyin;Li Yanyan;Du Jun(College of Forestry,Gansu Agricultural University,Lanzhou,Gansu 730070,China;College of Information Science and Technology,Gansu Agricultural University,Lanzhou,Gansu 730070,China)
出处
《水土保持通报》
北大核心
2025年第3期242-252,共11页
Bulletin of Soil and Water Conservation
基金
国家自然科学基金项目“旱作麦田土壤N_(2)O排放对耕作措施及水氮管理的响应模拟”(32360438)
甘肃省拔尖领军人才项目(GSBJLJ-2023-09)
甘肃省重点研究发展计划(22YF7FA116)
甘肃省财政专项(GSCZZ20160909)。
关键词
保护性耕作
旱作农田
春小麦
土壤碳通量
conservation tillage
dry farmland
spring wheat
soil carbon fluxes
