生物炭-有机肥堆肥对旱地红壤CH4和N2O通量的影响及微生物学机制

Climate warming has become the most globally serious and complex environment development and challenge. As one of the main source of greenhouse gas emissions, the emission reduction of soil CH4 and N2O and other greenhouse gas has become the focus of current research. Added biochar as filler in composting is a new research direction of the biochar-C and N cycle, but the research of relation between soil CH4, N2O flux and soil microorganism, and its responses to amendment of biochar-manure compost is very weak in upland red soil. A field experiment and the indoor control experiment will be set to study the characteristics soil carbon and nitrogen distribution, carbon combination and carbon utilization, to study the changes soil CH4, N2O flux, oil microbial activity (microbial biomass carbon, nitrogen and soil enzyme activities) and microbial population and community structure in upland red soil under the amendment of biochar-manure compost. The way of biochar-manure compost to reduce the production of greenhouse gases will be explored in upland red soil. Through these researches, the covariant relationship between soil CH4, N2O flux and soil microorganism will be discussed, the law of soil CH4, N2O flux and its microbial mechanisms will be revealed in upland red soil under the amendment of biochar-manure compost. It will also guide the optimization of organic manure amendments and the measures formulation of the greenhouse gas emission reduction in upland red soil in theory and practice.

气候变暖已成为全球最严重和复杂的环境发展与挑战。作为温室气体主要排放源之一，土壤CH4和N2O等温室气体减排已成为当前研究热点。堆肥中添加生物炭做填充剂是生物炭-CN循环一个最新的研究方向，但关于旱地红壤CH4和N2O通量与红壤微生物的关系及对生物炭有机肥堆肥的响应研究非常薄弱。本项目以室内控制和田间验证试验相结合，通过分析生物炭有机肥堆肥作用下旱地红壤碳氮变化和分配特点，CH4和N2O通量、微生物数量和群落结构的变化，探索有利于减少旱地红壤产生温室气体的生物炭-有机肥堆肥方式，阐明生物炭-有机肥堆肥作用下旱地红壤CH4和N2O通量、土壤碳氮与土壤微生物之间的协变关系，揭示生物炭-有机肥堆肥影响旱地红壤CH4和N2O通量的微生物学机制，可为南方旱地红壤的有机肥堆肥的合理施用和旱地红壤温室气体减排措施的制定提供理论与实践指导。

本项目以江西旱地红壤结合室内控制和田间验证试验，分析了不同物料来源（稻壳、小麦秸秆、玉米秸秆）和不同温度（300℃、550℃、800℃）制成的生物炭与有机肥（猪粪）堆肥作用下旱地红壤碳氮变化和分配特点、CH4和N2O排放动态和通量、微生物活性、数量和群落结构的变化。主要研究结果如下：.1）添加生物质炭降低了土壤温室气体的排放，B1、B2、B3处理N2O、CH4、CO2累计排放量分别降低了5.98%~8.54%、2.55%~4.15%和-4.77%~7.95%；且B2处理温室气体增温潜势（GWP）最低，最有利于旱地红壤温室气体减排。与有机肥相比，B1M、B2M、B3M处理N2O、CH4、CO2累计排放量分别降低了11.9%~17.8%、-4.51%~3.44%和38.53%~48.91%；生物质炭-有机肥堆肥处理土壤GWP显著了降低了23.35%，不同温度生物质炭-有机肥间无显著差异。.2）不同温度制备下的生物质有机肥堆肥对淀粉酶、蔗糖酶累计活性随着制备温度的升高而降低，脲酶表现出与之相反的规律。.3）低温度制备的生物质炭更有利于细菌、真菌的增长，且随着温度的升高，AOA、AOB基因拷贝数增加，nirK、nirS基因拷贝数降低。与M相比，B1M、B2M、B3M处理细菌、真菌、AOA、AOB、nirK、nirS基因拷贝数均降低，且各处理间差异不显著。.4）添加不同物料生物质炭显著降低土壤温室气体的排放，与CK相比，R、C和W处理土壤N2O、CH4和CO2的累计排放通量分别降低了51.4%~59.8%、34.8%~78.8%和12.6%~27.3%。C和W处理下的土壤GWP最低，对旱地红壤温室气体减排的效果最好，但两者之间并无显著差异。添加生物质炭-有机肥堆肥显著降低土壤N2O和CO2的排放，与M相比，RM、CM和WM处理土壤N2O和CO2的累计排放通量分别降低了56.5%~72.3%和31.3%~40%。CM处理旱地红壤GWP最低，对旱地红壤温室气体减排的效果最好。.5）不同物料生物质炭提升土壤总PLFAs含量，与CK相比提高了6.3%~7.9%，但生物质炭对于特征微生物群的相对丰度并无影响。生物质炭-有机肥堆肥降低土壤总PLFAs含量，与M相比降低了10.2%~23.3%，且降低了土壤真菌的相对丰度，提高了土壤细菌的相对丰度。