秸秆和硫酸铝对淡黑钙土有机矿质复合体及有机碳分布的影响

以吉林省典型土壤淡黑钙土为研究对象,采用室内恒温培养法研究在不同秸秆和硫酸铝添加量下,淡黑钙土中有机矿质复合体的含量及有机碳在其中的分布,探讨有机矿质复合体对淡黑钙土固碳的贡献。结果表明:对于秸秆和硫酸铝添加的所有处理,复合体含量均表现为G_1(钠分散组)G_0(水分散组)G_2(钠质研磨分散组);与对照相比,秸秆和硫酸铝添加使得淡黑钙土中G_0组复合体的含量降低,G_2组复合体的含量明显上升,而对G_1组复合体的含量影响不大。单位质量复合体中有机碳的含量大小表现为G_2G_0G_1,G_2组复合体中的有机碳含量最高(平均含量为95.92 g·kg~(-1)),约为单位质量G_0组和G_1组复合体中有机碳含量的3倍,G_0组(平均含量为33.89 g·kg~(-1))略高于G_1组(平均含量为32.25 g·kg~(-1))。秸秆和硫酸铝添加均有助于提高G_0组复合体中有机碳的含量;而G_1组复合体有机碳含量的变化主要受秸秆添加量的影响,随着秸秆添加量的增加,G_1组复合体有机碳含量增加;秸秆对G_2组复合体中有机碳含量的提高具有促进作用,而硫酸铝的影响则相反。各组复合体对淡黑钙土固碳的贡献率取决于土壤中复合体的含量及单位质量复合体中有机碳的含量,其对固碳贡献的大小顺序为G_1G_0G_2;有机矿质复合体(G_0+G_1+G_2)质量仅占淡黑钙土质量的约四分之一,但其对于淡黑钙土固碳的贡献却为61.96%~73.56%。

Effect of straw and aluminum sulfate on soil organic-mineral complex and organic carbon distribution in light Chernozem

The typical light Chernozem in Jilin Province was selected for analyzing the distribution of soil organic-mineral complex and the content of organic carbon at different content levels of straw and aluminum sulfate. Furthermore, the contribution of soil organic-mineral complex to organic matter sequestration in light Chernozem was investigated via laboratory simulative incubation. The results showed that the order of organic-mineral complex content was G₁ (sodium dispersion group) > G₀ (water dispersion group) > G₂ (sodium and abrasive dispersion group) for all treatments with straw and aluminum sulfate addition. Compared with S₀Al₀, the content of G₀ organic-mineral complex was decreased with straw and aluminum sulfate addition. The content of G₂ organic-mineral complex was increased significantly. However, straw and aluminum sulfate addition had little effect on the content of G₁ organic-mineral complex. The organic carbon content in the organic-mineral complex of unit mass followed the order of G₂ > G₀ > G₁. The organic carbon content in the G₂ complex was highest and the average content was 95.92 g·kg^-1, which was about three times the organic carbon content in the G₀ and G₁ complex.The organic carbon content in the G₀ complex was slightly higher than that of the G₁ complex (the average content was 32.25 g·kg^-1) and the average content was 33.89 g·kg^-1. Straw and aluminum sulfate addition could increase the organic carbon content in the G₀ complex, and the change of organic carbon content in the G₁ complex was mainly affected by straw addition. With the straw amount increasing, the organic carbon content in the G₁ complex was increased. Straw addition played a positive role for increasing the organic carbon content in the G₂ complex, however, the effect of aluminum sulfate was the contrary. The contribution of each organic-mineral complex to the soil carbon sequestration in light Chernozem depended on the organic carbon content in the complex and the complex content in soil. The organic carbon sequestration content in each organic-mineral complex followed the order of G₁ > G₀ > G₂. The contribution ratio of organic-mineral complex (G₀+G₁+G₂) to organic carbon sequestration in the light Chernozem was 61.96%~73.56%.