油茶壳及凋落叶生物质炭对土壤温室气体排放的影响

Effects of Camellia oleifera Leaf Litter and Fruit Shell-derived Biochar on Soil Greenhouse Gas Emissions

【目的】油茶壳是油茶(Camellia oleifera)产业有机废弃物,与凋落叶均可用于制备生物质炭。生物质炭可用于土壤改良,缓解土壤N_(2)O排放。研究旨在探讨油茶凋落叶和油茶壳生物质炭对油茶林地土壤温室气体的减排效果及其作用机理。【方法】采用完全交互设计,以油茶林地土壤为研究对象,在氮添加背景下研究施用生物质炭(油茶凋落叶和油茶壳)对土壤N_(2)O和CO_(2)排放的影响,以硝酸钾溶液为外源氮肥。【结果】(1)生物质炭处理显著提高土壤pH,且油茶凋落叶生物质炭的改良效果显著优于油茶壳生物质炭。与对照相比,油茶凋落叶和油茶壳生物质炭处理后,土壤pH分别提高了35.74%和24.46%。(2)生物质炭可降低土壤N_(2)O排放速率,油茶凋落叶生物质炭的抑制效果要强于油茶壳生物炭。与对照相比,油茶凋落叶和油茶壳生物质炭处理后,土壤N_(2)O排放速率分别减少了42.71%和7.66%。(3)生物质炭显著增加土壤CO_(2)排放速率,在未施氮条件下,油茶壳生物质炭处理下土壤CO_(2)排放速率显著高于油茶凋落叶生物质炭。与对照相比,油茶凋落叶和油茶壳生物质炭处理下,土壤CO_(2)排放速率分别增加了38.82%和85.70%。【结论】油茶凋落叶和油茶壳生物质炭可以有效缓解油茶土壤酸性,减缓土壤N_(2)O排放。油茶凋落叶生物质炭对油茶酸性土壤的改良效果和土壤N_(2)O的减排作用要优于油茶壳生物炭。油茶林经营中应充分利用凋落叶资源用于土壤改良及温室气体减排,以实现油茶产业可持续经营。

[Objective]Camellia oleiferafruit shell is the organic waste of Camellia oleifera industry,and it can be used to prepare biochar together with the Camellia oleifera leaf litter.Biochar can be used for soil improvement to alleviate soil N_(2)O emission.The purpose of this study is to explore the effect and mechanism of Camellia oleifera leaf litter and Camellia oleifera fruit shell biochars on soil greenhouse gas emission reduction in Camellia oleifera plantation land.[Method]In this experiment,the complete interaction design was adopted,taking the soil of Camellia oleifera plantation land as the research object,and potassium nitrate solution was used as exogenous nitrogen fertilizer,the effects of biochar(Camellia oleifera leaf litter and fruit shells)on N_(2)O and CO_(2)emissions from soil were studied.[Result](1)Biochar treatment significantly increased soil pH,and the improvement effect of applying biochar from camellia oleifera leaf litter was significantly better than that of biochar from Camellia oleifera fruit shells.Compared with the control,under the treatment of Camellia oleifera leaf litter and fruit shell biochar,soil pH increased by 35.74% and 24.46%,respectively.(2)Biochar could reduce soil N_(2)O emission rates,the inhibition effect of Camellia oleifera litter leaves biochar was stronger than that of Camellia oleifera fruit shell biochar.Compared with the control,under the treatment of Camellia oleifera leaf litter and fruit shell biochar,the N_(2)O emission rate of soil decreased by 42.71% and 7.66%,respectively.(3)The application of biochar could significantly increase soil CO_(2)emission rates.Under the condition of no nitrogen application,CO_(2)emission rates of Camellia oleifera leaf litter biochar treatment was significantly higher than that of Camellia oleifera fruit shells.Compared with the control,under the treatment of Camellia oleifera leaf litter and fruit shell biochar,soil CO_(2)emission rates increased by 38.82% and 85.70%,respectively.[Conclusion]Camellia oleiferaleaf litter and fruit shells biochar can effectively alleviate the acidity of Camellia oleifera soil and decelerate N_(2)O emission from soil.The improvement effect of Camellia oleifera leaf litter biochar on acid soil and N_(2)O reduction in soil are better than that of Camellia oleifera fruit shells biochar.In the management of Camellia oleifera plantation,the leaf litter resources should be fully used for soil improvement and greenhouse gas emission reduction,thus realizing the sustainable management of Camellia oleifera industry.