摘要
以江汉平原河滩砂质湿地起源土壤为例,研究稻田、棉田、桔园和未开垦湿地利用方式下表土有机碳含量变化及其在团聚体颗粒组内的分布和稳定性。结果表明:不同土地利用方式下表土有机碳含量差异显著,稻田显著高于其他土地利用方式,湿地、棉田和桔园间差异不显著。旱地减少了土壤有机碳的团聚体物理保护作用,而水田稻作条件下有助于形成土壤有机碳的团聚体物理保护作用。稻田、棉田、湿地均为2 000～200μm颗粒组比例最高,桔园200～20μm颗粒组比例最高,不同土地利用方式均为<2μm颗粒组比例最少。全土SOC的分配主要集中在2 000～200μm大团聚体颗粒组中,在<2μm颗粒组中最少。2 000～200μm大团聚体颗粒组LOC/SOC的比例最高,碳库不稳定,易于丢失;<2μm小颗粒组团聚体LOC/SOC的比例最低,碳库稳定。表明长江中游地区砂质湿地土壤开垦成稻田是相对较好的保持土壤有机碳库的土地利用途径。
Taking origins of the Sandy River wetland soil in Jianghan plain as an example, the effects of different land use types on distribution and stability of sandy flood wet land soil organic carbon aggregate in rice paddies and cotton fields, citrus orchard and uncultivated wetland were studied. The results showed that there was no significant difference of topsoil organic carbon contents under different land use patterns. SOC content of the rice fields was significantly higher than the other ways, but there was no significant difference among wetlands, cotton fields and garden. The use of dry-land reduced the effects of soil aggregates physical protection in organic carbon, but it was promoted under the rice season in paddy. Proportions of 2 000-200μm granules group of soil aggregates in rice paddies, cotton fields, wetlands were higher, just as proportion of 200-20μm particle groups in orange park. The proportion of 2μm particle group was the least in all land use types. The SOC content was mainly in the 2 000-200μm particle group, then 2 μm particle group. The proportion of LOC/SOC was the highest in 2 000-200 μm group of aggregate particles, and carbon was not stable and easy lost. The proportion of LOC/SOC was the lowest in 〈2μm group of aggregate particles, and carbon was stable. It showed that the paddy soil was the better land use type for keeping the carbon pool in sandy parent material of the middle region of the Yangtze River.
出处
《水土保持学报》
CSCD
北大核心
2013年第2期228-233,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(40830528)
内蒙古民族大学科研创新团队建设计划项目(NMD1003)
内蒙古民族大学博士科研启动基金项目(BS296)
关键词
湿地
农田
土地利用方式
土壤有机碳
团聚体
wet land
farm land
land use type
soil organic carbon（SOC）
coaeervate
