摘要
为探究微塑料污染对水稻秸秆还田下土壤有机碳矿化的影响,采集3种典型农田土壤(水稻土、红壤和潮土),进行70 d室内培养试验,每种土壤设置对照(control check,CK)、添加微塑料(polyethylene,PE)、添加水稻秸秆(rice straw,RS)、添加微塑料和水稻秸秆(rice straw-polyethylene,RS-PE)4个处理,测定各处理土壤理化性质、CO_(2)释放量、可溶性有机碳(soluble organic carbon,DOC)和微生物生物量碳(microbial biomass carbon,MBC)含量。结果显示:3种土壤中PE和RS-PE处理下70 d内CO_(2)累积释放量大小为潮土>稻土>红壤。与CK处理相比,RS处理后3种土壤CO_(2)累积释放量均显著增加,PE处理后红壤和潮土中CO_(2)累积释放量显著增加。添加微塑料和水稻秸秆提高了3种土壤DOC和MBC含量,促进土壤有机碳矿化。3种土壤中平均相对分子质量(E_(2)/E_(3))值依次为水稻土>红壤>潮土;且添加微塑料和水稻秸秆提高了土壤DOC平均相对分子质量、芳香性和疏水性。3种土壤有机碳矿化均与DOC E_(2)/E_(3)呈显著负相关,且水稻土和潮土有机碳矿化与DOC芳香性(SUVA254)和疏水性(SUVA260)呈显著正相关。研究结果表明,微塑料和水稻秸秆还田显著影响土壤有机碳的矿化。
Microplastics are widely present in soil,and the problem of microplastic pollution in soil has been considered during recent years.Three typical farmland soils including the paddy soil,the red soil and the fluvo-aquic soil were used to conduct indoor incubation experiments for 70 days to study the effects of microplastic pollution on the mineralization of organic carbon in soil under rice straw returning.4 treatments including the control(CK),addition of microplastics(polyethylene,PE),addition of rice straw(RS),addition of microplastics and rice straw(RS-PE)were set for each type of soil.The physical and chemical properties,the emission of CO_(2),the content of soluble organic carbon(SOC)and microbial biomass carbon(MBC)in each soil treated were measured.The results showed that the cumulative emission of CO_(2) from three types of soils within 70 days under the PE and RS-PE treatment was in the order of fluvo-aquic soil>paddy soil>red soil.Compared with CK,the cumulative emission of CO_(2) from three types of soils significantly increased after RS treatment,and the cumulative emission of CO_(2) from the red soil and fluvo-aquic soil significantly increased after PE treatment.Adding PE and RS increased the content of SOC and MBC in three types of soils,promoting the mineralization of organic carbon in soil.The E_(2)/E_(3) value in three types of soils was in the order of paddy soil>red soil>fluvo-aquic soil.The addition of PE and RS increased the average relative molecular weight,aromaticity,and hydrophobicity of SOC in soil.The mineralization of organic carbon in three types of soils was significantly and negatively correlated with the average relative molecular weight of SOC(E_(2)/E_(3)),and the mineralization of organic carbon in paddy and fluvo-aquic soil was significantly and positively correlated with the aromaticity(SUVA254)and hydrophobicity(SUVA260)of SOC.It is indicated that t the addition of microplastics and rice straw significantly affect the mineralization of organic carbon in soil.
作者
胡思晗
南倩茹
温丽莲
赵丽娅
HU Sihan;NAN Qianru;WEN Lilian;ZHAO Liya(College of Resources and Environment,Hubei University,Wuhan 430062,China)
出处
《华中农业大学学报》
CAS
CSCD
北大核心
2024年第6期219-228,共10页
Journal of Huazhong Agricultural University
基金
国家自然科学基金项目(22106041)。
关键词
微塑料
土壤
水稻秸秆
有机碳矿化
CO_(2)排放
microplastics
soil
rice straw
mineralization of organic carbon
emission of carbon dioxide
