滨海盐碱地不同造林树种林地土壤盐碱化特征

采用野外取样与室内分析测试相结合的方法,对不同林地土壤的全盐量、阴阳离子组成、总碱度、p H、电导率、碱化度等指标进行了系统研究。结果表明:对照空地与各林地土壤中均无CO32-存在,造林可明显改变土壤中Na+、Cl-、SO42-、HCO3-等可溶性盐离子的含量,降低土壤全盐含量,造林地土壤阴离子由SO42-+Cl-为主演变为SO42-+HCO3-为主。土壤p H、碱化度和总碱度的变化趋势一致,不同造林地土壤碱化程度以紫穗槐林地最大,柽柳林地次之。土壤全盐含量(y)和电导率(x)间呈极显著线性正相关,故可用电导率计算含盐量进行研究区域的盐渍化程度分级。研究结果可为阐明滨海盐碱地的盐碱化过程、指导土壤改良提供参考。

Salinization characteristics of afforested coastal saline soil as affected by species of trees used in afforestation

Soil samples were collected from afforested woodlots different in tree species for in-lab analysis of total salt content, anion and cation compositions, total alkalinity, pH, electrical conductivity, and alkalization degree, of which a systematic study was done. Results show: no CO32- was detected in a tract of clearing as control and all the woodlots; afforestation significantly changed the content of soluble salts, like Na , Cl-, SO42- and HCO3- and reduced the content of total salt in the soils; in afforested soils, anions SO42- HCO3- replaced SO42- Cl- in dominancy; soil pH and alkalization degree and total alkalinity varied in a similar trend; and among the woodlots, the one of Amorpha fruticosa was the highest in alkalization degree, and followed by Woodlot Tamarix chinensis; Correlation analysis indicates that soil total salt content (y) is in extremely significant positive linear relationship with electrical conductivity (x), so it is feasible to calculate total salt content with soil electrical conductivity in grading the area by salinization degree. The findings of the study may serve as reference in elucidating salinization-alkalization processes of the coastal saline soil and in ameliorating the soil in the Yellow River Delta.