不同培养温度下长期施肥水稻土的有机碳矿化特征  

Characteristics of soil organic carbon mineralization at different temperatures in paddy soils under long-term fertilization

作　　者：林杉[1] 陈涛[2] 赵劲松[1] 向荣彪[1] 胡荣桂[1] 张水清[3] 王米兰[1] 吕昭琪 

机构地区：[1]华中农业大学资源与环境学院,武汉430070 [2]湖北省十堰市农业局,湖北十堰442000 [3]河南省农业科学院植物营养与资源环境研究所,郑州450002

出　　处：《应用生态学报》2014年第5期1340-1348,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41201255;41171212);中央高校基本科研业务费专项资金项目(2013PY114);国家重点基础研究发展计划项目(2012CB417106)资助

摘　　要：选择湖南省3个国家级稻田肥力变化长期定位监测点的土壤，分别在10、20和30℃进行室内恒温培养试验，研究温度和施肥对土壤有机碳矿化的影响及其与不同碳形态含量的关系.结果表明：在培养前期（0～13d）土壤CO2产生速率较快，后期逐渐下降，其速率变化符合对数函数；升温促进了土壤有机碳矿化，各施肥处理土壤中，以秸秆还田和化肥配施有机肥处理土壤有机碳的累积矿化量较多；各施肥土壤的Q10值为1.01～1.53，与总有机碳、易氧化有机碳、胡敏酸碳和富里酸碳呈显著正相关；在10和20℃下CO2，矿化量与微生物生物量呈显著的线性相关关系，而30℃下则无显著相关关系；CO2矿化量与不同碳形态含量和胡敏酸碳／富里酸碳呈显著的线性正相关；在10℃下矿化率与不同碳形态含量呈显著的线性负相关，在20和30℃下，矿化率与不同碳形态含量无明显相关关系.因此可以通过施用秸秆和有机肥增加对土壤碳的固定，减缓大气CO2浓度的升高，减少温室气体排放.Dynamics of soil organic carbon mineralization affected by long-term fertilizations and temperature in relation to different soil carbon fractions were investigated in paddy soils. Soil samples were collected from the plough layer of 3 long-term national experimental sites in Xinhua, Ningxiang and Taojiang counties of Hunan Province. Mineralization of soil organic C was estimated by 33-day aerobic incubation at different temperatures of 10, 20 and 30 ℃. The results showed that the rates of CO2 production were higher during the earlier phase （0-13 d） in all treatments, and then decreased according to a logarithm function. Higher incubation temperature strengthened C mineralization in the different treatments. The quantities of cumulative CO2 production in NPK with manure or straw treatments were greater than in inorganic fertilizers treatments. The Q10 values in the different soil treatments ranged from 1.01-1.53. There were significantly positive correlations between the Ql0 values and soil total organic carbon （TOC）, easy oxidation organic carbon （EOOC） , humic acid carbon （CHA） , fulvic acid carbon （ CvA ）. The cumulative amount of miner alized C was significantly positively correlated with microbial biomass carbon （MBC） at 10 and 20 ℃, but not significantly at 30 ℃. Significant correlations were found between the cumulative amount of mineralized C and different soil carbon fractions and CHA/CvA. The correlations of differ-ent soil carbon fractions with the ratio of cumulative mineralized C to TOC were negatively correlated at 10 ℃, but not significantly at 20 and 30 ℃. These results suggested that the application of NPK with manure or straw would be helpful to increase the sequestration of C in paddy soils and reduce its contribution of CO2 release in the atmosphere.

关 键 词：长期施肥 水稻土 矿化作用 温度 

分 类 号：S153[农业科学—土壤学]