温度对不同粘粒含量稻田土壤有机碳矿化的影响  

Effects of temperature on organic carbon mineralization in paddy soils with different clay content

作　　者：任秀娥[1] 童成立[1] 孙中林[1] 唐国勇[1] 肖和艾[1] 吴金水[1] 

机构地区：[1]中国科学院亚热带农业生态研究所农业生态重点实验室

出　　处：《应用生态学报》2007年第10期2245-2250,共6页Chinese Journal of Applied Ecology

基　　金：国家重点基础研究发展规划项目(2002CB412503);中国科学院知识创新工程重要方向项目(KZCX2-YW-423);国家自然科学基金重点资助项目(40235057).

摘　　要：模拟了亚热带地区3种不同粘粒含量的水稻土(砂壤土、壤粘土、粉粘土)在5种温度(10、15、20、25和30℃)下的有机碳(SOC)矿化特征,分析SOC矿化对温度变化的响应.结果表明:在160d的培养期内,温度对3种水稻土SOC矿化量的影响有一定差异,30℃时砂壤土、壤粘土和粉粘土SOC矿化量分别是10℃时的3.5、5.2和4.7倍.在较低温度(≤20℃)下,SOC矿化速度较低且相对稳定;在较高温度(≥25℃)下,前期SOC矿化速度较高,随着培养时间的延长逐渐降低,并趋于稳定.3种水稻土SOC矿化的温度系数(Q10)随培养时间出现波动,砂壤土的Q10平均值最低,为1.92,壤粘土和粉粘土的Q10平均值较接近,分别为2.37和2.32;3种土壤矿化速率常数(k)与温度呈极显著的指数相关(P<0.01).3种水稻土有机碳矿化对温度变化的响应敏感度依次为壤粘土>粉粘土>砂壤土.An incubation test with three kinds of paddy soil （ sandy loam, clay loam, and silty clay soils） in subtropical region was conducted at 10, 15, 20, 25 and 30 ℃ to examine the response of the mineralization of soil organic carbon （SOC） to temperature change. The results showed that during the period of 160 d incubation, the accumulative mineralized amount of SOC in sandy loam, clay loam, and silty clay soils at 30 ℃ was 3.5, 5.2 and4.7 times as much as that at 10 ℃, respectively. The mineralization rate was lower and relatively stable at lower temperatures （ ≤ 20 ℃ ） , but was higher at the beginning of incubation and decreased and became stable as the time prolonged at higher temperatures （ ≥25 ℃ ）. During incubation, the temperature coefficient （ Q10 ） of SOC mineralization in test soils fluctuated, with an average Q10 in sandy loam, clay loam, and silty clay soils being 1.92, 2.37 and 2.32, respectively. There was a positive exponential cor- relation between SOC mineralization constant k and temperature （ P 〈 0. 01 ） , and the response of SOC mineralization to temperature change was in the order of clay loam soil 〉 silty clay soil 〉 sandy loam soil.

关 键 词：有机碳 矿化 温度 粘粒含量 稻田土壤 

分 类 号：S153[农业科学—土壤学]