盐分和底物对黄河三角洲区土壤有机碳分解与转化的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 盐分和底物对黄河三角洲区土壤有机碳分解与转化的影响 DOI: 10.5846/stxb201206290914 作者: 作者单位: 滨州学院山东省黄河三角洲生态环境重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41101220，41101277）；山东省优秀中青年科学家奖励基金项目（BS2011HZ001）；山东省高校科研发展计划项目（J13LE58）；滨州学院国家级大学生创新训练计划项目（201210449127）；滨州学院博士基金项目（2008Y05） Effects of salinity and exogenous substrates on the decomposition and transformation of soil organic carbon in the Yellow River Delta Author: Affiliation: Shangdong Key laboratory of Eco-enviromental Science for Yellow River Delta, Binzhou University, Binzhou 256603, Shandong, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤盐碱化能抑制微生物活性，影响土壤有机碳的分解与转化。以黄河三角洲盐碱耕地为研究对象，采用室内恒温培养法，设置3个NaCl盐分梯度（S1：0.1%；S2：0.5%；S3：0.9%），通过在土壤中添加不同底物（CK：不添加底物；N：添加氮；C：添加碳；C+N：添加碳+氮），研究该土壤释放CO2-C量、土壤微生物生物量碳（SMBC）、土壤微生物呼吸商（qCO2）及溶解性有机碳（DOC）对盐分和底物的响应。结果表明：在45 d的培养期内，CK、N处理中S1盐分土壤释放CO2-C量最高，S2和S3明显低于S1，降低幅度分别为18.3%-23.7%和24.3%-39.8%。C、C+N处理中3个盐分土壤释放CO2-C量差异较小，特别是在C+N处理中，3个盐分土壤释放CO2-C差异不显著。4个底物处理中，SMBC均在S1和S2盐分中含量较高，S3盐分最低。与CK相比，N处理并不能提高SMBC含量，C、C+N处理可明显提高SMBC，但S1和S2盐分土壤提高的幅度（80.4%-80.5%、58.0%-58.7%）明显高于S3（68.9%、49.7%）。4个底物处理中，qCO2均在S1盐分土壤中最高，C、C+N处理可明显提高qCO2。CK、N处理中3个盐分土壤DOC差异不显著，C、C+N处理中S3盐分土壤DOC较高。说明在无碳源输入条件下，增加盐分含量能明显抑制土壤释放CO2量。添加碳源后，盐分含量对土壤释放CO2的影响变小。微生物对碳源和盐分胁迫的响应较快，添加碳源能明显提高微生物数量及其活性。但较高盐分（含盐量 > 0.5%）可明显降低土壤微生物活性及对外源碳的利用率，导致较高盐分SMBC及qCO2较低而DOC较高。 Abstract:In the Yellow River Delta, nearly 50 percent of soils are saline and alkaline. Soil salinization can suppress microbial activity and thus affect the decomposition and transformation of soil organic carbon, while little information was found about the effects of salinity and exogenous C and N amendment on the decomposition and transformation of soil organic carbon in this area. A laboratory experiment was conducted to investigate the effects of soil salinity and exogenous substances on the turnover of organic carbon under conditions with 25℃ and 60% water holding capacity over 45 days. Three levels of salinity (S1: 0.1%; S2: 0.5%; S3: 0.9%) using NaCl (w/w) were imposed in the saline-alkaline cultivated soil in Yellow River Delta. Soil was amended with or without C (750 mg/kg) or inorganic N (30 mg/kg) as glucose or NH4Cl, and 4 treatments were established, including (Control: no substrates addition, N: NH4Cl addition, C: glucose addition, C+N: glucose and NH4Cl addition). The CO2-C emission, soil microbial biomass carbon (SMBC), dissolved organic carbon (DOC) and calculation of the respiratory quotient(qCO2)were determined. Without glucose addition, the cumulative amount of CO2-C emission was highest in S1 during the incubation, and it was decreased by 18.3%-23.7% and 24.3%-39.8% in S2 and S3 compared with S1, respectively. After glucose addition, the cumulative amount of CO2-C emission little changed among the three salinity soils, and especially it was no significant difference between the three salinity soils in C+N treatment. SMBC was higher in S1 and S2 than that in S3 under the four treatments with substrates addition. Addition of NH4Cl had no significant effect, but addition of glucose significantly increased SMBC, and SMBC increased by 80.4%-80.5% or 58.0%-58.7% in S1 and S2 in C or C+N treatment, and only 68.9% or 49.7% in S3. The qCO2 was significant higher in S1 than that in S2 and S3, and it was significantly improved with glucose addition. Compare with the control, DOC reminded unchanged in the N treatment, but it increased in S3 with glucose addition. It was suggested that the CO2 emission could be depressed with the increase of soil salinity without C addition, and soil salinity had little influence on CO2 emission after C addition. Microorganism was more sensitive to exogenous carbon and soil salinity. The size and the activity of microbial biomass would be improved with C addition, but higher salinity (>0.5%) could depress the microbial activity and the utilization of exogenous carbon, resulting in higher SMBC and qCO2 and lower DOC in higher salinity soil. 参考文献 相似文献 引证文献