长期定位施肥对潮土腐植酸含量及其相关因素的影响

利用中国科学院封丘农业生态国家实验站潮土农田生态系统养分平衡长期定位试验地，研究不同施肥处理对春秋两季土壤腐植酸含量、微生物生物量碳及转化酶活性的影响。结果发现，与不施肥对照相比，单施NK或单施PK对土壤pH和有机碳含量均没有显著影响；单施有机肥、施NPK化肥、1/2 OM + 1/2 NPK有机无机配施以及施NP等4种处理均显著抑制了土壤pH的升高，提高了土壤有机碳与全氮含量；其中单施有机肥还显著提高了土壤腐殖质中胡敏酸的含量以及微生物生物量碳和转化酶活性，有机肥与化肥配施效果次之。结果表明，长期施用有机肥更有利于提高土壤肥力质量与健康质量。

Changes in soil humic acid,microbial biomass carbon and invertase activity in response to fertilization regimes in a long- term field experiment

A long-term located field for nutrients equipoise experiment in Fengqiu National Agro-ecological Experiment Station was conducted to investigate the effects of different fertilization on soil humic acid concentrations, soil microbial biomass, and invertase activities of fluvo-aquic soils. There are seven treatments of the experiment: organic manure (OM), half organic manure plus half fertilizer (1/2OMN), fertilizer NPK, fertilizer NP, fertilizer NK, fertilizer PK, and the control (CK, without fertilization). The results show that soil organic carbon and total nitrogen concentrations are significantly different with a similar pattern among fertilization regimes, and the order from high to low is OM, 1/2OMN, NPK, NP, PK, NK, which was just contrary to soil pH. Generally speaking, only organic manure increased soil humic acid significantly. In addition, OM had highest soil microbial biomass C and invertase activitiy, while 1/2OMN took the second place. It indicated that, long-term organic fertilization would be better on elevating soil fertility and health properties.