呼伦湖蓝藻对典型退化草原区不同类型土壤性质的影响

Effects of Cyanobacteria from Hulun Lake on Properties of Different Types of Soils in Typical Degraded Grassland Area

近年来呼伦湖蓝藻水华频发,当地应对手段多以打捞为主,如何处理打捞上岸的蓝藻藻液成为需要解决的首要问题之一.接种蓝藻被证实对土壤具有一定的修复功能,但所用蓝藻多为人工培养的本土陆生藻,淡水藻对土壤性质的影响尚不明确.该研究基于呼伦湖气候特征、经济发展等实际情况,选择本土典型退化草原区两种类型土壤——栗钙土和砂性土,按质量比0%、1%、3%、5%、10%依次施加蓝藻藻液,观测蓝藻藻液对土壤性质的影响.结果表明:(1)与对照相比,施加蓝藻藻液能够改善呼伦湖栗钙土和砂性土的理化性质,使土壤有机质含量升高5.50%~103.93%、全氮含量升高10.27%~166.46%、有效磷含量升高12.84%~573.16%,土壤pH降低2.34%~12.43%,且对砂性土养分含量的提升更显著.(2)施加蓝藻藻液对两种典型土壤的水分蒸发均有较好的抑制作用,可提高土壤吸水能力和保水性,同一施藻量情况下,蓝藻对两种不同土壤蒸发的抑制作用相近,蒸发量较对照降低17.10%~59.44%.(3)施用10%蓝藻藻液对两种典型土壤性质的改善效果最好,能够显著提高土壤尤其是砂性土的养分含量,增强吸水能力和保水性,虽然土壤全盐量有所升高,但总量偏低.综合而言,在呼伦湖退化草地和沙地施用蓝藻藻液是一种提高土壤质量的新选择,对于本地蓝藻资源化利用模式探索具有重要意义.

In recent years,cyanobacterial blooms have occurred frequently in Hulun Lake,and the local response method is mainly to remove cyanobacteria from the lake.How to handle the collected cyanobacteria from the lake has become one of the primary problems to be solved.Cyanobacteria inoculation has been proven to have a certain restorative function on soil,but the cyanobacteria used are mostly cultured native terrestrial algae,and the effect of freshwater algae on soil properties is still unclear.Based on the climatic characteristics and economic development of Hulun Lake,two types of soil,chestnut soil and sandy soil,were selected in a typical local degraded grassland area,and the cyanobacteria weight ratios were set at 0%,1%,3%,5% and 10% to observe the effect of cyanobacteria on soil properties.The results showed that:(1)Compared with the control treatment,cyanobacteria could improve the physical and chemical properties of chestnut soil and sandy soil in Hulun Lake.The organic matter content increased by 5.50%-103.93%,the nitrogen content increased by 10.27%-166.46%,the content of available phosphorus increased by 12.84%-573.16%,the pH decreased by 2.34%-12.43%,and the nutrient content of sandy soil increased more significantly.(2)The application of cyanobacteria stock solution had a good effect on the water evaporation of the two typical soils,which could improve soil water absorption and water retention.Under the same amount of algal application,the inhibitory effect of cyanobacteria on the evaporation of the two soils was similar,and the evaporation was reduced by 17.10%-59.44% compared with the control.(3)The application of 10% cyanobacteria stock solution had the best effect on the improvement of the two typical soil properties,which could significantly increase the soil nutrient content and enhance the water absorption capacity and water retention capacity,especially sandy soil.Although the soil total salt content increased,the total amount was low.In conclusion,the application of cyanobacteria stock solution in degraded grassland and sandy land in Hulun Lake is a new treatment method to improve soil quality,and this is of great significance for exploring the beneficial utilization of local cyanobacteria.