后续施肥措施改变对水稻土团聚体有机碳分布及其周转的影响

发布时间：2018-05-14 11:02

本文选题：喀长期定位试验 + 红壤性水稻土　；参考：《土壤》2017年05期

【摘要】：利用一个长达30 a且已进行适当变更的长期定位施肥试验,改施C4玉米秸秆以替代C3水稻秸秆,运用δ~(13)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(化肥改为常量有机肥、常量有机肥改为高量有机肥、高量有机肥改为化肥、常量有机肥改为化肥)3 a后对红壤性水稻土团聚体有机碳分布及其周转的影响。结果表明:在所有施肥处理条件下红壤性水稻土团聚体分布以大团聚体(0.25 mm)为主,占72.48%~86.33%。与施用化肥30 a相比,长期施用常量有机肥、高量有机肥有利于促进红壤性水稻土粗大团聚体(2 mm)的形成,并提高团聚体平均重量直径(MWD)。团聚体中有机碳含量随着团聚体粒径的增大而增大,大团聚体更有利于有机碳富集。长期常量有机肥、高量有机肥处理下红壤性水稻土中有机碳主要贮存在粗大团聚体(2 mm)中,而长期化肥处理下以细大团聚体(2~0.25 mm)对土壤有机碳贡献率最高。外源新碳施入量越多,全土和各粒径团聚体新碳含量越高,且外源新碳主要分布在大团聚中。在后续施肥措施改变3年后,增加有机肥施入量(化改常、常改高)2 mm粗大团聚体、MWD、全土及各粒径团聚体中有机碳含量将分别显著提高7.08%~73.13%、5.38%~44.22%、14.53%~38.50%、0.70%~35.86%;而减少有机肥施入量(高改化、常改化)则与之相反,分别降低28.17%~43.20%、21.17%~31.54%、17.54%~27.30%、11.49%~29.77%。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,从而进一步维持或改善土壤结构,提高土壤有机碳含量。
[Abstract]:A long-term fertilization experiment, which has been changed for 30 years, was carried out to replace C3 rice straw with C4 corn straw. The application of high organic fertilizer and constant organic fertilizer was studied by using 未 ~ (13) C natural abundance method. Fertilizer and when its fertilization measures change (chemical fertilizer to constant organic fertilizer, constant organic fertilizer to high organic fertilizer, high organic fertilizer to fertilizer, The effect of organic fertilizer on the distribution and turnover of aggregate organic carbon in red soil paddy soil after 3 years of conversion from organic fertilizer to chemical fertilizer. The results showed that the aggregate distribution of red soil paddy soil was 0.25mm (72.48mm) and 86.33mm (72.48mm). Compared with chemical fertilizer application for 30 years, long-term application of constant organic fertilizer and high organic fertilizer could promote the formation of coarse aggregates (2 mm) and increase the average weight diameter of aggregates. The content of organic carbon in aggregates increases with the increase of particle size, and the large aggregate is more favorable for the enrichment of organic carbon. The organic carbon in the red soil paddy soil was mainly stored in the coarse aggregate (2 mm) under the treatment of long-term constant organic fertilizer, but the contribution rate of the fine and large aggregate to the soil organic carbon was the highest under the treatment of long-term chemical fertilizer. The higher the amount of exogenous new carbon applied, the higher the new carbon content of the whole soil and the aggregates with different particle sizes, and the exogenous new carbon mainly distributed in the large agglomeration. Three years after the change of the following fertilization measures, the amount of organic fertilizer application increased, the organic carbon content in the whole soil and in the aggregates of different particle sizes increased significantly, respectively, and the organic carbon content in the whole soil and in the aggregates with different particle sizes increased significantly, while the organic carbon content in the whole soil and in the aggregates with different particle sizes increased significantly (38.50 0.7035.866.86), while the organic fertilizer application decreased the amount of organic fertilizer application. ) on the contrary, they reduced 28.17, 43.20, 21.17, 31.54, 17.54, 27.30, 11.49, and 29.7777, respectively. In order to maintain or improve the soil structure and increase the soil organic carbon content, the application of organic fertilizer should be continued or increased in the process of agricultural production in the red soil rice planting area of southern China, so as to further maintain or improve the soil structure and increase the soil organic carbon content.
【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)资助
【分类号】：S153.6

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