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为研究芦苇对盐渍地土壤盐分改良及分布规律的影响,对芦苇种植前后及单生长季内不同土壤层次的pH、电导率、有机质、盐分分布特征进行测定,结果表明:(1)经过7年的芦苇种植改良,土壤中Ca~(2+)、Mg~(2+)、Cl~-、SO_4~(2-)、HCO_3~-、CO_3~(2-)6种盐分离子的含量均显著降低60%以上。(2)单生长季内随着芦苇的生长,土壤粘粒含量有向下运移的趋势,表层土壤(0~20cm)粘粒含量有少量减少;底层(40~60cm)土壤粘粒含量少量提高。同时表层土壤pH值和电导率显著下降,中层变化不显著,下层则略有升高。(3)芦苇种植的盐渍地表层土壤有机质含量显著高于中层和底层,且单生长季内表层土壤有机质含量随芦苇的生长,由8.95g·kg~(-1)提高到11.80g·kg~(-1),提高显著,但中层和底层土壤有机质变化幅度较小,相对稳定。(4)芦苇出苗期盐渍地土壤盐分的表聚现象明显,表层土壤各类盐离子含量均显著高于中层和底层,但后期表层盐分含量下降明显,即芦苇对盐渍土的改良在单生长季内效果显著,其中以对表层土壤盐分改良效果最好。
In order to study the effect of reed on the salinity improvement and distribution in salinized soil, the characteristics of pH, conductivity, organic matter and salinity of different soil layers before and after reed planting and single growing season were studied. The results showed that: (1) The reed planting in the year was improved. The contents of Ca ~ (2 +), Mg ~ (2 +), Cl ~ -, SO 4 2-, HCO 3 ~ - and CO 3 2- in the soil were all improved Significantly reduced by more than 60%. (2) With the growth of Phragmites australis in the single growing season, the clay content in the soil tends to migrate downward. The content of clay in the surface soil (0 ~ 20cm) decreases slightly. The content of clay in the bottom layer (40 ~ 60cm) improve. At the same time, the surface soil pH and conductivity decreased significantly, the middle layer was not significantly changed, the lower layer was slightly increased. (3) The content of organic matter in the salinized surface layer of reed was significantly higher than that in middle layer and bottom layer, and the content of organic matter in surface soil layer increased from 8.95g · kg -1 to 11.80g · kg -1 in the single growing season ~ (-1), but the change of soil organic matter in the middle and bottom soil was relatively small and relatively stable. (4) Phenomenon of apparent aggregation of salinity in salinized soil was obvious at the seedling stage of reed, and the contents of various kinds of salt ions in surface soil were significantly higher than those of the middle and bottom, but the salinity of the surface layer decreased obviously in the later stage. During the growing season, the effect was remarkable, of which the best effect was the improvement on the surface soil salinity.