种植耐盐植物对滨海盐碱地土壤盐分的影响

摘要

为了揭示不同耐盐植物根际土壤与对照之间的盐分差异，通过大田试验研究了田菁、苜蓿、苏丹草、碱蓬4种耐盐植物不同生长时期各土层可溶性盐分和盐分离子的测定分析，研究了4种耐盐植物根际土壤与对照土壤中的可溶性盐分和主要盐分离子的运移特征。结果表明：种植耐盐植物对表层土壤具有明显的脱盐效果，其中田菁对表层及0～80 cm土层的脱盐效果最好。10月份时耐盐植物处理表层土脱盐效果顺序为田菁＞苏丹草＞苜蓿＞碱蓬；0～80 cm整体各处理的脱盐顺序为田菁＞苜蓿＞苏丹草＞碱蓬。 HCO3-、Cl-和SO42-均在对照的0～10 cm土层中含量最高，耐盐植物根际土壤0～10，10～20 cm土层中Na＋和Cl-含量要显著低于对照土壤的含量。种植耐盐植物后，根际土壤中可溶性Ca2＋含量增加，使更多的Na＋被取代后将其移除到耕层以下，说明种植耐盐植物处理对Na＋的移除效果比较明显。%Field experiments were conducted to investigate the characteristics of soluble salt contents and main salt contents of rhizosphere soil from four different salt-tolerant plants and comparison treatment .The aim of these experiments was to reveal the salt contents difference between the rhizosphere soil of four salt -tolerant plants and comparison treatment .The results showed that four salt-tolerant plants treatments had obvious function of restraining salt accumulation in surface layer .Sesbania cannabina Pers.had best effects on restrainting the accumulation of soil salinity in surface layer and 0-80 cm layers.The reduced water-soluble salt sequence in surface layer from high to low was Sesbania cannabina>Sorghum sudanense>Medicago sativa>Suaeda salsa on October,18th,2013;the re-duced water-saluble salt sequence from high to low for all over the 0-80 cm layers was Sesbania cannabina >Medicago sativa>Sorghum sudanense>Suaeda salsa.HCO3 -,Cl-and SO4 2-exhibited enrichment in 0-10 cm layer of comparison treatment;Na +and Cl -reduced significantly in the rhizosphere soil of four tested plants than comparison treatment for 0-10 cm and 10-20 cm layers.Ca2+increased significantly in the rhizosphere soil of four tested plants than comparison treatment among the whole layers .More and more Na +was replaced by Ca 2+with the cultivating four salt-tolerant plants,therefore the effects was extremely obvious for Na +removement by planting salt-tolerant plants .