粘质吹填盐土秸秆高效改良脱盐动态研究

为了构建合理的吹填盐土改良技术并探索其改良效果，采用蒸渗仪土柱模拟试验法，对设置秸秆掺拌、秸秆柱、秸秆层综合处理的土柱和对照土柱进行了持续淋水条件下粘质吹填盐土脱盐动态的研究。研究显示：与对照相比，秸秆技术处理能够显著提高土壤的通透性，提高盐分淋洗速率和单位水量淋盐量，缓解盐分的逐层累积现象和返盐现象，缩短淋盐时间、节约淡水资源达50%以上。对照土柱淋盐过程中出现了较为明显的碱化现象，而改良土柱秸秆形成大孔隙以及脱硫石膏的添加，有效缓解了碱化现象。对照土柱淋盐后，有机质、全氮含量均显著降低，而改良土柱通过秸秆掺拌等有效提高了有机质、全氮含量。结果表明，该项技术对粘质吹填盐土的改良具有节约淡水、提高淋盐速率、抑制脱盐碱化现象和缩短淋盐时间的作用。

The Desalting Dynamics of Clayey Saline Dredger Fill After Efficiency Improvement with Straw Treatment

In order to develop a sound saline soil improvement technique and find its application effects, the author introduced lysimeter column test, in which desalting dynamics in clayey saline dredger fill columns treated with straw mixture, straw column and straw layer and the CK column were observed respectively under the condition of continuous water leaching. The results showed that: compared with the CK column, the former could remarkably improve soil permeability and water desalting rate and constrain salt accumulation and resalinization. Moreover, it could shorten desalting time and save over 50% fresh water. Soil alkalization was obviously observed in the CK column, while it was not the case in improvement column as big pores were formed by straw and flue gas desulfurization gypsum was added. Both organic matter and nitrogen content were reduced in the control column, but they were increased in improvement column after the straw was added. Those findings indicate that this technique could effectively reduce water usage, increase desalting rate, curb soil alkalization and shorten desalting time in improving clayey saline dredger fill.