中国生态农业学报2016，Vol.24Issue(10)：1300-1309,10.DOI:10.13930/j.cnki.cjea.151318
不同生物质炭输入水平下旱作农田温室气体排放日变化研究
Diurnal variations of greenhouse gases emissions under different biochar applications
摘要
Abstract
Biochar is a carbon-rich solid product obtained from heating biomass under oxygen-limited conditions. Biochar application has the potential to mitigate greenhouse gas emission. Dryland farming areas in Northwest China emit substantial amounts of greenhouse gases. The aim of this study was to determine the effects of different biochar rates on diurnal variations in methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) emissions in the western Loess Plateau. Treatments included 6 biochar application rates (3 replications): 0 t·hm-2 (control, B0), 10 t·hm-2 (B1), 20 t·hm-2 (B2), 30 t·hm-2 (B3), 40 t·hm-2 (B4) and 50 t·hm-2 (B5) t·hm-2. Soil moisture and temperature were measured concurrently with gas measurement. The results showed distinct diurnal variations in CO2, CH4 and N2O fluxes for different biochar application rates. The trends of change in the fluxes of the 3 gases (CH4, N2O and CO2) were consistent with daily variations in temperature. Daytime fluxes were greater than nighttime fluxes. The order of absorption peak of CH4 was B0 (10.14 mg·m-2·h-1) > B1 (7.82 mg·m-2·h-1) > B2 (6.57 mg·m-2·h-1) > B5 (2.89 mg·m-2·h-1) > B4 (1.05 mg·m-2·h-1) > B3 (-0.10 mg·m-2·h-1). A similar order was noted for average emission flux of N2O, given as B0 (288.79 mg·m-2·h-1) > B1 (201.78 mg·m-2·h-1) > B5 (164.02 mg·m-2·h-1) > B2 (157.14 mg·m-2·h-1) > B4 (154.60 mg·m-2·h-1) > B3 (112.06 mg·m-2·h-1). The order of average emission flux of CO2 was B0 (85.44 mg·m-2·h-1) > B1 (80.91 mg·m-2·h-1) > B2 (76.49 mg·m-2·h-1) > B5 (69.10 mg·m-2·h-1) > B4 (67.19 mg·m-2·h-1) > B3 (65.29 mg·m-2·h-1). The results showed that when biochar input was less than 30 t·hm-2, mean emission fluxes of CH4, N2O and CO2 dropped with increasing biochar application rate. However, when biochar input exceed 30 t·hm-2, the mean emission fluxes of CH4, N2O and CO2 increased with increasing biochar application rate. The soil was a good source of atmospheric CH4 for all treatments (except for 30 t·hm-2) and sources of atmospheric N2O and CO2, irrespective of treatment. Soil temperature at 5 cm depth was correlated with biochar application rate — y = -0.017 6x + 16.585 (R² = 0.302 6, r = -0.55, P <0.05), but soil moisture at 5 cm soil depth was linearly correlated with biochar application rate — y = 0.056 5x + 13.626 (R2=0.815 1, r = 0.903, P < 0.05). The average fluxes of CH4, N2O and CO2 under the control treatment were positively correlated with soil temperature of both soil surface and the 0-5 cm depth. The others treatments were also positively correlated with different levels of biochar. Biochar application at 30 t·hm-2 reduced greenhouse gas emission. The differences in both soil temperature and moisture caused by different input levels of biochar were the main reasons for the differences in CH4, N2O and CO2 emissions. Correction coefficient and regression analysis of optimal measure time revealed that the optimal observation period of the three greenhouse gases was between 8 a.m. and 9 a.m.关键词
旱作农田/春小麦/生物质炭/温室气体/排放通量/日变化/土壤温度/土壤水分Key words
Dry farmland/Spring wheat/Biochar/Greenhouse gases/Emission flux/Diurnal variation/Soil temperature/Soil moisture分类
资源环境引用本文复制引用
宋敏,蔡立群,齐鹏,StephenYeboah,张仁陟,罗珠珠,潘占东,卢廷超..不同生物质炭输入水平下旱作农田温室气体排放日变化研究[J].中国生态农业学报,2016,24(10):1300-1309,10.基金项目
甘肃省干旱生境作物学重点实验室开放基金课题(GSCS-2012-13)、国家自然科学基金项目(31160269,31571594)、“十二·五”《循环农业科技工程》项目(2012BAD14B03)和甘肃省自然科学基金项目(145RJZA204,145RJZA106)资助@@@@* Supported by the Open Found of Gansu Provincial Key Lab of Aridland Crop Science Project (GSCS-2012-13), the National Natural Science Foundation of China (31160269,31571594), the Project of the Twelfth Five-Year Plan for Circular Agriculture Science and Technology (2012BAD14B03) and the Natural Science Foundation of Gansu Province (145RJZA204,145RJZA106) （GSCS-2012-13）
