中文摘要：

为阐明植被覆盖与施肥管理综合作用下黑土活性有机碳的数量特征,探讨合理调控农田土壤质量的施肥模式。本试验以中国科学院海伦农业生态实验站长期定位试验为平台,对比和研究了草地与农田生态系统中不同施肥处理下土壤总有机碳、颗粒有机碳、微生物生物量碳、冷水提取有机碳以及热水提取有机碳数量上的差异及相互关系。结果表明：经过25年的自然恢复,草地生态系统中土壤有机碳及各活性有机碳的数量显著高于农田生态系统中的无肥处理（P〈0.05）。农田生态系统中,化肥处理对农田土壤有机碳和活性有机碳的提高作用并不明显;经过长期化肥＋有机肥处理后,农田土壤总有机碳与各活性组分的数量较无肥和化肥处理显著提高（P〈0.05）,除微生物生物量碳外,总有机碳与其他活性有机碳组分的数量均达到草地植被下的碳水平,土壤总有机碳及冷水和热水提取有机碳的含量与草地生态系统的差异不显著,颗粒有机碳含量比草地生态系统坛加43.7%。相关性分析表明,土壤有机碳总量、微生物生物量碳、冷水提取有机碳以及热水提取有机碳两两之间的相关性均达到显著或极显著水平。长期化肥与有机肥配施是提高黑土有机碳及其活性有机碳数量的有效措施。

英文摘要：

The objective of this study was to clarify the effect of vegetation covering and long-term fertilization on characteristics of soil labile organic carbon fractions,and discuss fertilization mode for controls of soil quality.Based on the long-term position experiments in Hailun Agricultural Ecology Station of Chinese Academy of Sciences,the concentrations and correlations of SOC（Soil organic carbon） and labile organic carbon fractions,including POC（Particulate organic carbon）,MBC（Microbial biomass carbon）,WSOC（Water-soluble carbon） and HWSOC（Hot water-soluble carbon） were compared and researched between grassland ecosystem and different fertilization treatments in farmland ecosystem.The results showed that after twenty-five years experiment,the content of SOC and its labile fractions in grassland was significantly higher than that of NF（no fertilizer） treatments in farmland ecosystem（P 0.05）.There was no significant increase in the content of SOC and its labile fractions in NP（Chemical fertilizer applied） treatment.Compared to NF and NP treatments,SOC and its labile fractions increased markedly after long-term NPM treatment（Chemical fertilizer amended with organic manure applied）（P 0.05）.Except for MBC,SOC and other labile organic fractions in NPM treatment become identical with that of grassland,POC content was higher than that of grassland by 43.7%,and there was no significant difference in HWSOC and WSOC between grassland and NPM treatment.Furthermore,highly significant correlations took place among SOC,SMBC,HWSOC and WSOC.Long-term application of chemical fertilization amended with organic manure was a better way to increase soil organic carbon and its labile fractions in farmland.