沼渣连续施用对土壤有机碳组成及剖面分布的影响

Effects of Continuous Application of Biogas Residue on the Quality of Soil Organic Carbon in the Profile of Purple Soil

通过“棉花-小麦”轮作田沼渣施用试验，研究沼渣连续施用对土壤有机碳组成及分布的影响。结果表明：沼渣施用使土壤中总有机碳、微生物碳、易氧化有机碳和难氧化有机碳含量均随施用沼渣年限‘的延长而增加；对于不同的沼渣施用年限，其各层的增幅变化趋势不一致，沼渣连续施用3年使0～30cm土壤中总有机碳、微生物碳、易氧化有机碳和难氧化有机碳含量均极显著增加，而沼渣连续施用5年对40-50cm土层微生物碳亦无显著影响。这对维持土壤养分供应与土壤结构稳定性具有重要意义。

Based on the experiment of continuous use of biogas residue in cotton-wheat rotation field, effects of continuous application of biogas residue on the constitution and vertical distribution of soil organic carbon of purple soil were studied. The results showed that application of biogas residue promoted the accumulation of soil organic carbon, microbial biomass carbon and organic carbon, readily and hardly to be oxidized with the extension of biogas residue using time. However, the increasing range of each layer was inconsistent. The content of total organic carbon, microbial biomass carbon, readily oxidized carbon and hardly oxiddized carbon was increased remarkably in the 0~30 cm soil layer after 3-year continuousapplication of biogas residue, while the content of soil microbial biomass carbon in the 40~50 cm soil layer was not greatly affected by 5-year continuous use of biogas residue. It is of great importance to keep soil nutrients and soil structure stability.