利用方式对紫色水稻土有机碳与颗粒态有机碳的影响  

Variation of total and particulate organic carbon in topsoil of a Purple paddy under different land use practices

作　　者：黄雪夏[1] 唐晓红[2] 魏朝富[2] 谢德体[2] 

机构地区：[1]广州大学环境科学与工程学院,广东广州510006 [2]西南大学资源环境学院,重庆400716

出　　处：《生态环境》2007年第4期1277-1281,共5页Ecology and Environmnet

基　　金：国家自然科学基金重点项目(40231016)

摘　　要：土壤是陆地生态系统中重要的动态碳库,其微小的变化可能带来对全球大气CO2浓度的较大变化。颗粒态有机碳在土壤中周转速度较快,比土壤总有机碳更易受土地利用方式的影响,对于评价土地利用变化对土壤碳固定过程影响具有重要意义。采集不同的耕作、轮作和施肥处理的14年28茬的紫色土长期试验土壤,分析有机碳与颗粒态有机碳含量在土壤及不同深度分布特点,结果表明:长期垄作免耕并实行水稻(Oryza sativa)油菜(Brassica)轮作的利用方式下,0～10cm土层土壤有机碳与颗粒态有机碳含量明显高于其他利用方式下,而稻油水旱轮作平作利用方式下最低。整个耕层0～30cm深度的土壤有机碳含量介于8.92～29.98g·kg-1之间,颗粒态有机碳含量变幅为0.54～3.43g·kg-1之间,且存在随深度递增而降低的趋势。土壤有机碳与颗粒态有机碳都可用作评价利用方式影响紫色水稻土土壤质量变化与固碳能力的有效指标,但颗粒有机碳对于管理措施的响应更为敏感。从总有机碳与颗粒有机碳的关系来看,不同管理下有机碳的增加与土壤物理保护能力的提高有关。垄作免耕(稻油)的利用方式最有利于有机碳的保护和稳定。　Soil C stock is believed as an important and dynamic C stock of the Earth terrestrial ecosystem,of which a small loss even at 0.1% would impose great change in atmospheric CO2 concentration. Particulate organic carbon （POC） of soil may be indicative of important information for land use changes as it has shorter residence time than total organic carbon （TOC）. The authors sampled topsoils from a long-term experiment field of a purple paddy soil from Chongqing,China and analyzed the contents and depth distribution of TOC and POC respectively. The paddy had been treated continuously with different tillage and cropping systems since 1991 containing 28 cropping seasons within the total 14 years. The results obtained are as follows. A maximum topsoil （0～10 cm） content of both TOC and POC was found under ridge tillage with rice （Oryza sativa） and rape （Brassica） rotation,and a minimum of them under leveling tillage and rice and wheat rotation. The TOC contents of the total plow layer of 0-30cm ranged from 8.92g·kg^-1 to 29.98 g·kg^-1 and that of POC from 0.54 ～3.43 g·kg^-1,decreasing with the soil depth under all the treatments. An exponential regression of POC content with TOC was observed. It is suggested that both TOC and POC content could be considered as an indicator for evaluating the land use change on soil quality,but POC to be more sensitive. And the SOC enhancement under ridge tillage and rice and rape rotation may be associated with the enhanced physical protection of sequestered C in course aggregates,which was promoted under minimum tillage with ridge and rice and rape rotation.

关 键 词：利用方式 紫色水稻土 总有机碳 颗粒态有机碳 

分 类 号：S153.6[农业科学—土壤学]