土壤盐渍化程度对造林的影响

为了探讨土壤盐渍化程度对造林结果的影响，以便有效利用盐碱地资源，在黄河三角洲选择轻（0.8~1.6 g/kg）、中（2.0~3.1 g/kg）、重（4.7~6.9 g/kg）不同盐渍化程度的土地进行绒毛白蜡和侧柏造林，调查分析2种树种在不同盐渍化程度地块上的成活率、株高和地径生长及受害情况。结果表明：绒毛白蜡在轻度和中度盐渍化地块生长良好，成活率分别为94.1%、83.3%，侧柏在轻度盐渍化地块生长良好，成活率为88.9%；2种树种在重度盐渍化地块生长受到显著抑制，成活率分别为22.2%、11.1%，受害叶片增加，达到30%~50%。因此，在黄河三角洲造林，首先要考虑土壤的盐渍化程度，绒毛白蜡可作为轻度和中度盐渍化土地造林的主要树种，侧柏只能用于轻度盐碱地造林。对重度盐渍化土地首先要进行土壤改良，使土壤含盐量达到中度含盐量以下时，再进行造林才能收到好的造林效果。

Effect of Soil Salinity Degrees on Afforestation

In order to explore the effects of soil salinization on afforestation, and use saline-alkali soil resources effectively, the degrees of mild （0.8-1.6 g/kg）, moderate （2.0-3.1 g/kg）, and severe （4.7-6.9 g/kg） salinity land in the Yellow River Delta were selected for afforestation with Fraxinus velutina Tort. and Platycladus orientalis （L.） Franco. The survival rate, growth of plant height and diameter, and damage symptoms were investigated and analyzed. The result showed that： F. velutina grew well in mild and moderate salinization land, the survival rate were 94.1% and 83.3%, respectively. P. orientalis grew well in mild salinization land, and the survival rate was 88.9%. The growth of two species were inhibited significantly in severe saline land, and the survival rates were 22.2% and 11.1%, respectively. The injured leaves were increased to 30%-50% in severe saline land. It was proposed that to achieve good results of plantation in the Yellow River Delta, key consideration should be soil salinization, F. velutina should be a major afforestation species in mild and moderate salinization land, but P. orientalis should be only used in mild salinity land. Severe salinization land must be improved to moderate before afforestation.