不同类型植物耐盐特性对脱硫废弃物的响应及其耐盐指数综合评价
Response of salt tolerance of different salt-tolerant plants to flue gas desulphurization waste and a comprehensive evaluation of salt tolerance of plants
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摘要: 为探讨施用脱硫废弃物对生长在盐土和碱土上的不同植物耐盐特性的影响, 并建立综合评价指标体系, 对不同植物的耐盐指数进行综合评价。本试验在2008-2010年期间, 分别在碱土区和盐土区2个试点, 以施与不施脱硫废弃物为主处理, 选用9种不同耐盐植物为副处理开展了田间裂区试验, 观测分析了各耐盐植物的出苗特征、生长生理特征、产量等指标及土壤盐分、养分、碱化度(ESP)等性质, 从而建立包括植物生长、生理指标、土壤指标和经济指标的综合评价指标体系, 并应用TOPSIS法对不同耐盐植物的耐盐指数进行综合评价。结果表明: 与CK相比, 施用脱硫废弃物能显著改善各耐盐植物的生长发育, 提高出苗率、相对生长速率(株高)和相对生物量, 增加自由水和束缚水的比值(F/B), 且在碱土上效果优于盐土。不同类型耐盐植物之间差异显著, 表现出各自的耐盐、碱特性。同时施用脱硫废弃物种植耐盐植物可提高土壤有机质增加速率和全盐、碱化度的降低速率。同样地, 对盐碱土的改良效果表现为碱土优于盐土, 不同耐盐植物之间差异显著。通过综合评价把不同耐盐植物分为强、较强、中和弱4个耐盐等级。与CK相比, 施用脱硫废弃物可提高耐盐植物的耐盐等级, 扩展耐盐植物在盐碱地上的种植范围。由此可知, 耐盐植物的耐盐特性受植物类型、盐碱地类型、改良措施等因素影响。因此, 从生态经济的角度寻求合理的综合评价方法来确定耐盐植物的耐盐特性具有重要科学意义, 可为进一步优化盐碱地生态修复模式提供理论支持。Abstract: This study analyzed the effects of flue gas desulphurization waste (FGDW) on salt tolerance of different salt-tolerant plants in saline and alkali soils and developed a comprehensive evaluation system for salt tolerance of different salt-tolerant plants. A split-plot experiment was conducted in 2008 2010 at 2 different test sites, respectively representing saline and alkali soils. FGDW was applied to the main plots and sub-plots planted with nine representative salt-tolerant plants. The mode of growth, development, and physiological properties of salt-tolerant plants; soil organic matter, total salt content and exchangeable sodium percentage (ESP) were analyzed. Then a comprehensive evaluation index system, including plant growth index, physiological index, soil index and economic index was developed. Next, salt tolerance of different species was evaluated using TOPSIS (technique for order preference of similarity to ideal solution). The results suggested that compared with CK, FGDW treatment increased emergence rate, relative growth rate, relative biomass and free-to-bound water ratios of different salt-tolerant plants planted in saline and alkali soils. The effects were more obvious in alkali soil than in saline soil. Application of FGDW accelerated soil organic matter formation and decreased soil salt content and ESP. Similarly, significant differences were noted among the salt-tolerant plants and improvement effects were better in alkali than saline soils. Through comprehensive evaluation, the nine species were divided into four different salt tolerance levels - strongest tolerance, stronger tolerance, moderate tolerance and weak tolerance. Application of FGDW enhanced salt tolerance level and widened planting range of salt-tolerant plants. Salt tolerance properties of plants were influenced by different factors, including plant type, soil type, soil amelioration measures, etc. It was therefore important to seek comprehensive evaluation methods to grasp ecological and economic salt tolerance properties of salt-tolerant plants. This could lay theoretical basis for the development of superior ecological reclamation modes for saline-alkali soils.