耐盐菌联合化学复合改良剂协同改良黄河三角洲盐碱土壤的效果

为探究生物和化学方法联用对黄河三角洲地区盐碱土的改良效果，首先进行粉煤灰的改性和土著耐盐菌的筛选，选取其中2株耐盐菌(BY-4、BY-8)与化学复合改良剂(改性粉煤灰+脱硫石膏+腐殖酸(FSZ))通过联合配施的方法开展室内土柱淋溶试验，研究渗滤液和土壤中盐基阳离子、可溶性有机碳(DOC)、土壤钠吸附比(SAR)以及土壤有机质等的变化规律。结果表明：BY-4和BY-8除具有明显的耐盐和产吲哚乙酸能力，还分别具有较高的溶磷与解钾能力；与对照(CK)处理相比，添加化学复合改良剂(FSZ)能显著促进水溶性Na⁺的淋洗，降低土壤中水溶性Na⁺的总含量和SAR值，提高土壤中DOC和有机质含量，且耐盐菌BY-8联合化学复合改良剂的处理(FSZ8)效果最好；与CK相比，FSZ8处理下土壤水溶性Na⁺总量下降33.30%,耕层土壤SAR下降79.76%,DOC淋溶损失下降34.60%,耕层土壤有机质含量上升79.47%。研究结果有助于理解耐盐菌在改良盐碱土壤中的作用，并可为生物和化学复合改良剂的研发和利用提供理论和数据参考。

Effects of Salt-tolerant Bacteria Combined with Chemical Compound Amendment on Improving Saline-alkali Soil in the Yellow River Delta

In order to explore the improvement effects of the combined application of biological and chemical methods on saline-alkali soil in the Yellow River Delta, we first modified fly ash and isolated indigenous salt-tolerant bacteria, and then selected two strains of salt tolerant bacteria (BY-4 and BY-8) to carry out an indoor soil column leaching experiment in combination with a chemical compound amendment (i.e., modified fly ash+desulfurization gypsum+humic acid (FSZ)). The changes of base cations, dissolved organic carbon (DOC), sodium adsorption ratio (SAR) and soil organic matter in leachate and/or soil were studied. The results showed that the two strains BY-4 and BY-8 were salt tolerant and had the abilities to produce indole acetic acid and to solubilize phosphate or potassium. In compared with the treatment (CK), treatments with chemical compound amendments (FSZ) significantly promote the leaching of water-soluble Na⁺, reduced the total amount of water-soluble Na⁺ and SAR in soil, and increased the contents of DOC and organic matter in soil. The treatment of BY-8 combined with chemical compound amendment (FSZ8) performed the best. Compared with CK, soil total water-soluble Na⁺ under FSZ8 treatment decreased by 33.30%, SAR of arable soil decreased by 79.76%, DOC leaching loss decreased by 34.60% and organic matter content of arable soil increased by 79.47%. These findings were helpful to understand the role of salt-tolerant bacteria in soil improvement, and would provide theoretical and data reference for the development and utilization of biological and chemical composite amendments in the future.