后续施肥措施改变对红壤性水稻土团聚体有机碳组分的影响

发布时间：2018-05-03 11:50

本文选题：长期定位试验 + 红壤性水稻土　；参考：《水土保持学报》2016年06期

【摘要】：利用一个长达30年且已进行适当变更的长期定位施肥试验,采用物理方法对团聚体有机碳进行分组,并运用δ13 C自然丰度方法,研究长期施用高量有机肥、常量有机肥、化肥及当其施肥措施改变(化改常、常改高、高改化、常改化)3年后红壤性水稻土团聚体有机碳组分含量及其分布比例的变化规律,以期为调控稻田土壤肥力及红壤性水稻土有机碳库的管理提供理论依据。结果表明:与施用化肥30年相比,长期施用有机肥显著提高了红壤性水稻土团聚体总有机碳、粗游离态颗粒有机碳(cfPOC)、细游离态颗粒有机碳(ffPOC)、闭蓄态颗粒有机碳(oPOC)及矿物结合态有机碳(MmMOC)的含量,其中以游离态颗粒有机碳变幅最大,达67.5%~150.0%,对施肥最敏感,能较好地反映长期施肥下土壤有机碳库的变化。在后续施肥过程中,增加有机肥施入量(化改常、常改高)团聚体总有机碳、粗游离态颗粒有机碳(cfPOC)、细游离态颗粒有机碳(ffPOC)、闭蓄态颗粒有机碳(oPOC)及矿物结合态有机碳(MmMOC)含量将分别显著提高5.2%~15.5%,2.8%~40.2%,18.9%~43.9%,2.8%~17.6%,5.1%~8.2%;而减少有机肥施入量(高改化、常改化)则与之相反,分别降低15.8%~20.9%,12.6%~26.9%,24.6%~48.4%,19.9%~23.9%,4.9%~21.9%。在所有施肥处理条件下闭蓄态颗粒有机碳(oPOC)分布比例最低,为11.3%~13.4%;矿物结合态有机碳(MmMOC)分布比例最高,为50.4%~59.0%,是红壤性水稻土固存有机碳的主要形式。外源新碳施入量越多,大团聚体及其各有机碳组分的新碳含量越高,且45.6%~50.1%进入矿物结合态有机碳组分,34.1%~42.3%进入游离态颗粒有机碳组分,11.8%~18.0%进入闭蓄态颗粒有机碳组分。因此,在我国南方红壤性稻作区的农业生产过程中应继续或加大施用有机肥,从而进一步维持或提升土壤不同组分有机碳库。
[Abstract]:In this paper, a long-term fertilization experiment, which has been changed for 30 years, was used to group organic carbon in agglomerates by physical method, and 未 13 C natural abundance method was used to study the long-term application of high organic fertilizer and constant organic fertilizer. The content of organic carbon and the distribution of organic carbon in the aggregate of paddy soil in red soil were changed after 3 years after the change of fertilizer and its fertilization measures (change of chemical, high, high and regular). In order to provide theoretical basis for regulating soil fertility in paddy field and management of organic carbon pool in paddy soil of red soil. The results showed that compared with chemical fertilizer application for 30 years, long-term application of organic fertilizer significantly increased the aggregate total organic carbon (TOC) of paddy soil in red soil. The contents of coarse free particulate organic carbon (CfPOC), fine free particle organic carbon (FOC), closed storage particulate organic carbon (POC) and mineral bound organic carbon (MmMOC) were the most variable in free particulate organic carbon (67.5%), which were the most sensitive to fertilization. It can better reflect the change of soil organic carbon pool under long-term fertilization. In the process of fertilizer application, the amount of organic fertilizer applied was increased, and the total organic carbon (TOC) was increased. The contents of crude free particulate organic carbon, fine free particle organic carbon, closed storage organic carbon and mineral bound organic carbon MmMOC) will be significantly increased by 5.2g / L 15.52.8cm / 40.2c / 18.9B, 43.92.8b / 17.65.1m / 8.2d, respectively, while reducing the amount of organic fertilizer applied (high transformation, permanent modification) will be the opposite. The amount of 15.820. 9 is 12.6and the amount of 26.9is about 24.66.48.4and 23.90.4.9and 21.9. Under all fertilization conditions, the distribution ratio of closed particulate organic carbon (POC) was the lowest (11.3%), and that of mineral bound organic carbon (MmMOC) was the highest, 50.4% (59.0%), which was the main form of organic carbon sequestration in red paddy soil. The higher the amount of exogenous new carbon applied, the higher the new carbon content of large aggregates and their organic carbon components, and 45.60.1% of them entered the mineral bound organic carbon component (34.1%) and 42.3% of them entered the free particulate organic carbon component (11.88%) and 18.0% of them entered the closed particle organic carbon component. Therefore, the application of organic fertilizer should be continued or increased in the process of agricultural production in the red soil rice cropping area of southern China, so as to further maintain or enhance the soil organic carbon pool with different components.
【作者单位】：湖南农业大学资源环境学院;
【基金】：国家自然科学基金项目(41371250) 湖南省研究生科研创新项目(CX2015B267)
【分类号】：S153.6

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