冻融循环条件下生境基材中三种功能微生物数量变化规律研究

为揭示高寒地区典型生境基材中功能微生物数量变化的规律,以黄棕壤土为试验土样,在两种初始含水率条件下,分别制备客土、植被混凝土以及加菌植被混凝土三种不同类型的生境基材进行冻融循环模拟试验,探讨生境基材类型、初始含水率和冻融循环次数对基材中功能微生物数量的影响。试验结果显示:三种基材中功能微生物数量均受冻融循环影响显著,且随冻融循环次数增加总体呈"下降~上升~下降"趋势;冻融循环过程中,三种基材中功能微生物总量存在显著性差异,排序为:加菌植被混凝土植被混凝土客土,且固氮、解钾微生物数量显著低于解磷微生物;含水率为22%的基材中功能微生物总量普遍高于含水率为18%的基材。研究结果表明,加菌植被混凝土的肥力、抗冻性相比客土和植被混凝土有一定程度提升,但仍需对现有功能菌剂配方加以改进,以适应高寒地区冻融环境。

A study on the change of three functional microorganism quantities in habitat substrate under freezing-thawing cycles

To reveal the quantitative change of functional microbes in typical habitat substrate in the alpine regions,the freezing-thawing cycle test was conducted.Using yellow-brown loam as soil specimen,three habitat substrates including carrying soil,vegetation concrete and vegetation concrete adding microorganism were prepared with two kinds of initial moisture content.According to the test,the effects of habitat substrate type,initial moisture content and frequency of freezing-thawing cycle on the functional microbe quantities in substrate were explored.The results were as follows:(1) The functional microbe quantities in the three kinds of substrates were significantly affected by the frequency of freezing-thawing cycle,with a change trend of descending,rising and then decreasing again with the increase of cycle times.(2) During the freezing-thawing cycles,there were significant differences in the total quantity of functional microbes among three substrates;the sequence of significant variance was:vegetation concrete adding microorganism ＞ vegetation concrete ＞ carrying soil;the quantity of nitrogen fixation and potassium solubilizing of microorganisms were significantly lower than the quantity of phosphate-solubilizing.(3) The total quantity of functional microbes in the substrate with an initial moisture content of 22％ was higher than that with an initial moisture content of 18％.According to the above results,the frost resistance of vegetation concrete adding microorganism is higher than that of carrying soil and vegetation concrete,while the functional microorganisms agent still needs to be improved to adapt to the freezing-thawing environment in the alpine regions.