耐盐碱植物对滨海盐碱地的改良效果

为了解不同耐盐碱植物对盐碱地的改良效果,在天津滨海地区营造白刺、杜梨、银水牛果3种林地,造林4 a后分别对3种林地的土壤微生物数量、养分和盐分质量分数进行了研究。结果表明:土壤养分和微生物数量在土壤剖面上具有相同的垂直分布特征,随着土层深度增加而减少。白刺、杜梨和银水牛果林地土壤在各土层中盐分质量分数为1.426～1.900 g.kg-1,基本无差别;对照土壤在0杜梨>银水牛果,其中白刺和杜梨林地土壤养分和微生物数量远大于对照,差异达到显著水平(P<0.05)。银水牛果林地同对照土壤相比,除细菌、放线菌、全N差异未达显著水平(P<0.05),其它养分指标和真菌数量差异均达到显著水平(P<0.05)。土壤微生物和土壤养分呈正相关关系,二者与土壤盐分质量分数都成负相关关系。总体来看,白刺改良盐碱土的效果最好,杜梨次之,银水牛果较差。

Ameliorative Effect of Saline-Alkali Tolerant Plants in Coastal Saline-Alkali Land

A study was conducted to explore the ameliorative effect of saline-alkali tolerant plants on saline-alkali land through planting Nitraria tangutorum,Pyrus betulaefolia,Shepherdia argentea in Tianjin coastal region.The amount of microorganisms,nutrient content and salt content in soil in the three forestlands were studied 4 years after afforestation.Results showed that soil nutrient content and amount of microorganisms decreased with soil depth.Salt content in different soil layers ranged from 1.426 to 1.900g·kg-1.There was no difference in salt content between the three forestlands.However,the salt contents in 0-10,10-20,20-30cm soil layers in the control were 2.143,4.286,5.717g·kg-1,which increased with soil depth.Salt content in N.tangutorum,P.betulaefolia and S.argentea forestlands was obviously lower than that in the control.Soil nutrient content and amount of soil microorganisms in N.tangutorum forestland were highest,followed by P.betulaefolia and S.argentea.The soil nutrient content and amount of microorganisms in N.tangutorum and P.betulaefolia forestlands were much higher than those in the control,and there was a significant difference at the 0.05 level.Except for amounts of bacteria and actinomycetes and total nitrogen content in S.argentea forestland,other nutrient indexes and amount of fungi were all significantly different from those in the control at P<0.05.Amount of microorganisms was positively correlated with soil nutrient content,while they were both negatively related with soil salt content.On the whole,N.tangutorum is the best plant for the improvement of saline-alkali soil,followed by P.betulaefolia and S.argentea.