摘要
以黄淮海平原潮土为研究对象,通过室内恒温恒湿培养方法,比较研究了土壤中纤维素是否存在时,外源无机氮和葡萄糖添加对土壤微生物生物量及其活性的影响变化。实验设8个处理,包括不加任何物质的对照(CK)、添加无机氮(N)、葡萄糖(G)、纤维素(C)处理及葡萄糖和无机氮同时添加(G+N)处理,以及在纤维素存在基础上添加无机氮(C+N)、葡萄糖(C+G)、葡萄糖和无机氮同时添加(C+G+N)处理。在33天培养时间内,分别在不同的时间间隔内测定了土壤CO2累积释放量、微生物生物量碳(Cmic)、及脱氢酶(DHD)、β-葡萄糖苷酶(GLU)、过氧化氢酶(CAT)、碱性磷酸酶(APH)活性。结果表明,所有测定的微生物性质在CK与C处理间均没有显著性差异。与CK和C处理相比,其他所有处理的土壤CO2累积释放量均显著增加,其中C+G+N处理达最大值;G、G+N、C+G、C+G+N处理的土壤Cmic含量及DHD和APH活性显著提升,尤其在培养的前14天,而N和C+N处理则与CK处理相似,表示添加葡萄糖可显著增加上述处理生物活性水平,而添加无机氮则不能。添加无机氮和葡萄糖对GLU和CAT的影响不明显,大部分情况下它们在处理间没有表现出显著性差异。相关性分析表明,CO2释放速率始终与APH活性成显著正相关,但与Cmic和其他酶活性之间的相关关系则随着培养时间的不同而发生变化,这可能与不同培养时间的微生物组成或微生物利用底物的模式发生改变有关。聚类分析结果进一步表明,8个处理的土壤微生物活性水平可明显分成3组,其中活性水平最高的组只包含C+G+N处理,该结果提示在难分解纤维素存在时,无机氮和易利用有机碳的同时添加对提升土壤微生物活性的重要性。
Changes in soil microbial biomass carbon and enzyme activity in fluvo-aquic soil of the North China Plain were investigated after the soil, with or without cellulose, was amended with inorganic nitrogen and glucose in the experiment of incubation under constant temperature and humidity. The experiment was designed to have 8 treatments, i.e. control （CK）, addition of inorganic nitrogen （N）, addition of glucose （G）, addition of cellulose （C）, addition of glucose and inorganic nitrogen （C＋N）, addition of inorganic nitrogen in soil with cellulose （C＋N）, addition of glucose treatment in soil with cellulose （C＋G）, and addition of glucose and inorganic nitrogen in soil with cellulose （C＋G＋N）. Cumulative soil carbon dioxide release, microbial biomass carbon and activities of dehydrogenase, β-glucosidase, catalase, and alkaline phosphatase were measured, separately at various intervals during the 33 days of incubation. Results show that in all microbial parameters no significant difference existed between CK and Treatment C. As against Treatments CK and C, all the treatments displayed a significant increase in cumulative carbon dioxide release, with Treatment C＋G＋N listed on the topmost. Treatments G, G＋N, C＋G, and C＋G＋N all showed an obvious increment in Cmic content and DHD, APH activity, particularly during the first two weeks of the incubation, while Treatments N and C＋N displayed similarly like CK result. The findings implied that glucose could significantly increase microbial activity, but inorganic nitrogen could not. The effects of glucose and inorganic nitrogen on GLU and CAT were not obvious and in most cases no significant difference was found between different treatments. Correlation analysis demonstrates that carbon dioxide release rate was always positively related to APH activity, but not to Cmic and other enzymes activities and their relationships varied with the time of incubation, which was probably due to variation of the composition of soil microbial community or the way soil microbs utilize the substrates with the time of incubation. Cluster analysis further indicates that the 8 treatments could be sorted into three groups according to their soil microbial activity. Treatment C＋G＋N was the only one in the group of the highest activity, which suggests that it is important to amend the soil containing hard-to-decompose cellulose with inorganic nitrogen and readily available organic carbon at the same time for improving its soil microbial activity.
出处
《土壤学报》
CAS
CSCD
北大核心
2012年第1期139-146,共8页
Acta Pedologica Sinica
基金
国家重点基础研究发展计划(973)项目(2011CB100506)
中国科学院知识创新工程重大项目(KSCX2-EW-N-08)资助
关键词
纤维素
无机氮
葡萄糖
微生物生物量碳
酶活性
CO2累计释放量
Cellulose
Inorganic nitrogen
Glucose
Microbial biomass carbon
Enzyme activity
Cumulative CO2 release
