黑土区水稻土水稳性团聚体有机碳及其颗粒有机碳的分布特征

发布时间：2018-03-18 10:40

本文选题：黑土区　切入点：水稻土　出处：《水土保持学报》2016年04期 　论文类型：期刊论文

【摘要】：为研究黑土区水稻土水稳性团聚体有机碳及其颗粒有机碳含量和δ~(13) C值的分布特征,探讨黑土区水稻土水稳性团聚体有机碳及其颗粒有机碳的分布和稳定性,为该地区黑土的合理利用及土壤的合理培肥提供理论依据,以黑土区不同有机碳含量的水稻土为研究对象,利用湿筛法和物理分组技术分离提取各级团聚体及其颗粒有机物,采用~(13) C稳定同位素质谱技术分析有机碳含量及其δ~(13) C值。结果表明,黑土区水稻土以2~0.25mm团聚体为主,土壤有机碳主要富集在0.25mm团聚体中,尤其是2~0.25mm团聚体中;团聚体有机碳的δ~(13) C值随团聚体粒级的减小而增大,2mm和2~0.25mm团聚体中有机碳的δ~(13) C值均小于土壤有机碳的δ~(13) C值,具有碳截获或碳固定能力,而0.25~0.053mm和0.053mm团聚体中有机碳的δ~(13) C值均大于土壤有机碳的δ~(13) C值,具有碳固持或稳定的能力;除B-2土样外,各土样均以2~0.25mm团聚体中的颗粒有机碳含量为最大,以0.25~0.053mm团聚体中的颗粒有机碳含量为最小,且该团聚体中颗粒有机碳含量与土壤有机碳含量呈显著正相关关系(r=0.917,P0.01),表明微团聚体闭蓄态的颗粒有机碳对土壤有机碳的固持和稳定发挥重要作用。土壤颗粒有机碳及各级团聚体中颗粒有机碳的δ~(13) C值均小于土壤有机碳及各粒级团聚体中有机碳的δ~(13) C值,团聚体颗粒有机碳的δ~(13) C值也随团聚体粒级的减小而增大。因此,黑土区水稻土中0.25mm的水稳性团聚体是有机碳的主要载体,团聚体颗粒有机碳作为活性碳库,较总有机碳更易反映黑土区水稻土有机碳的周转变化,其敏感性随团聚体粒级的增大而增强。
[Abstract]:In order to study the distribution characteristics of water stable aggregate organic carbon and its particulate organic carbon content and 未 ~ (13) C value of paddy soil in black soil area, the distribution and stability of water stable aggregate organic carbon and its particulate organic carbon in black soil were studied. This paper provides a theoretical basis for the rational utilization of black soil and the rational fertilization of soil. Taking paddy soil with different organic carbon content in black soil area as the research object, the aggregates and their particulate organic matter are separated and extracted by wet sieve method and physical grouping technique. The organic carbon content and 未 ~ (13) C value of paddy soil in black soil area were analyzed by using stable isotope mass spectrometry. The results showed that the rice soil in black soil was mainly composed of 0.25mm aggregate, and soil organic carbon was mainly enriched in 0.25mm aggregate, especially in 2o 0.25mm aggregate. The 未 ~ (13) C value of organic carbon in aggregates increased with the decrease of particle size of aggregates, and the 未 ~ (13) C values of organic carbon in aggregates of 2mm and 0.25mm were lower than those of soil organic carbon, and had the ability of carbon interception or carbon fixation. However, the 未 ~ (13) C values of organic carbon in 0. 25 ~ 0. 053 mm and 0. 053 mm aggregates were higher than those in soil organic carbon and had the ability of carbon sequestration or stabilization, except for B-2 soil samples, the content of particulate organic carbon in 2 ~ 0. 25 mm aggregate was the largest. The content of particulate organic carbon in 0.255mm agglomerate was the smallest. There was a significant positive correlation between particulate organic carbon content and soil organic carbon content in the aggregate, indicating that the closed particulate organic carbon of microaggregate plays an important role in soil organic carbon sequestration and stability. The 未 ~ (13) C values of carbon and particulate organic carbon in aggregates were lower than those of soil organic carbon and organic carbon in various aggregates, and the 未 ~ (13) C values of particulate organic carbon were lower than those of soil organic carbon and organic carbon. The 未 ~ (13) C value of aggregate particles also increases with the decrease of aggregate size. Therefore, the water-stable aggregate of 0.25 mm in paddy soil in black soil is the main carrier of organic carbon, and the aggregate particulate organic carbon is used as active carbon pool. Compared with the total organic carbon, the organic carbon turnover of paddy soil in black soil area was more easily reflected, and its sensitivity increased with the increase of aggregate grain size.
【作者单位】：沈阳农业大学土地与环境学院农业部东北耕地保育重点实验室;
【基金】：国家自然科学基金项目(41571280,41101276)
【分类号】：S153.6

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