长期不同施肥处理水稻土溶解性有机碳降解特性研究  

A Study on The Characterisctics of Dissolved Organic Carbon Biodegradation in Paddy Soils Amended with Different Long-term Fertilization

作　　者：禹洪双[1] 刘勤[1] 陈武荣[1] 张亚楠[1] 胡安永[1] 曹志洪[1] 

机构地区：[1]中国科学院南京土壤研究所常熟农田生态系统国家实验站,南京210008

出　　处：《土壤通报》2013年第2期338-342,共5页Chinese Journal of Soil Science

基　　金：中德科学中心中德合作项目(GZ518);公益性行业(农业)科研专项经费项目(201203030)资助

摘　　要：利用水稻土长期定位试验和室内培养方法，研究了不同施肥处理对水稻土溶解性有机碳（DOC）含量及其生物降解特性。结果表明，长期施用化肥对DOC含量无明显影响，而化肥配施秸秆和化肥配施猪粪显著增加水稻土DOC含量。不同施肥处理水稻土DOC降解率为17．97％-39．18％。化肥配施猪粪处理（c1＋M）和化肥配施秸秆处理（c2＋s）水稻土的DOC降解能力强于对照（CK）和单施化肥处理（c2和c3）。DOC降解符合双指数衰变模型，水稻土DOC分别由周转时间约为1天的易降解部分和周转时间约为0．61～2．28年的难降解部分组成。降解过程中DOC溶液中结构较复杂的芳环物质比例前期呈上升趋势，后期趋于稳定，与其中易降解组分的降解有关。DOC的降解率与UV280之间存在极显著的负相关关系（P〈0．01）。A long-term fertilization trial was conducted to study the effect of various fertilizer applications on dissolved organic matter （DOC） and biodegradation of DOC （BDOC）. The results showed that the concentration of DOC was not significantly affected by chemical fertilizer＇s applications, while was significantly increased with the combined application of chemical fertilizers plus straw or pig manure. The biodegradation of DOC in C 1 ＋ M and in C2 ＋ S was higher than CK, C2 and C3. After a 42-day incubation, there was a broad range of biodegradation rates of DOC varying from 17.97% to 39.18% of total DOC, and the low molecular weight components could be degraded within a few days. Degradation rates of DOC of paddy soil under various fertilizer applications were quite faster in the period of early incubation, model. DOC was the turnover time then gradually slowed down. The DOC degradation kinetics obeyed a double exponential decay composed of two different degradation rate constants including labile DOC and refractory DOC, and of easily degradable part （labile DOC） was within 1 day and the turnover time of refractory DOC was within 0.61 - 2.28 years. During the incubation, the ratio of complex increased in the period of early incubation, and then declined in the biodegradation of labile components in DOC solution. The biodegradati UV280 absorbance. structure dissolved organic matter in solution late period, which being related to the rapid on rate of DOC was negatively related to the

关 键 词：长期施肥 水稻土 溶解性有机碳 生物降解 UV280 

分 类 号：S157.41[农业科学—土壤学] S153.5[农业科学—农业基础科学]