铝对土壤微生物区系组成的影响

通过大豆盆栽试验,研究了金属铝对土壤微生物区系组成的影响。结果表明,当铝质量分数<1.1 g/kg时,土壤细菌、放线菌的数量随着铝质量分数的增加而增加;当铝质量分数>1.1 g/kg时,土壤细菌、放线菌的数量随着铝质量分数的增加而减少。铝对丝状真菌的生长具有明显的促进作用。在低质量分数下,铝对土壤氨化细菌、硝化细菌、反硝化细菌具有一定的刺激作用;当质量分数>1.1 g/kg时,则表现为抑制作用,最大抑制率分别达48%、96%和95%;土壤硝化细菌、反硝化细菌可以作为铝污染土壤生态环境的指示菌。自生固氮菌的数量随铝质量分数的升高而逐渐下降。铝对土壤微生物区系产生抑制作用的临界质量分数在1.3 g/kg左右。

Effects of aluminum stress on the microflora of red soil

The study deals with the effect of aluminum (Al) stress on the microflora of red soil in soybean pot culture experiment. The red soil in soybean pot culture experiment exhibited an increase in bacteria and actinomycetes when Al mass fraction was lower than 1.1 g/kg and a decrease when Al mass fraction was higher than 1.1 g/kg. Al had a significant and stimulative effect on soil fungi. Al had a similar effect on ammoniation bacteria, nitrifier and denitribacteria to bacteria and actinomycetes. The maximum ratio of Al inhibiting ammoniation bacteria, nitrifier and denitribacteria reached 48%, 96% and 95%, respectively. The number of azotobacteria was gradually reduced with increasing concentration of Al. Nitrifier or denitribacteria could be used as indicator bacteria for Al-polluted soil, and the critical mass fraction of Al was about 1.3 g/kg.