Al^(3+)胁迫对茶园土壤微生物区系及生理群的影响

Effect of Al^(3+) on populations and major physiological groups of microbes in tea garden soils

以茶园土壤为研究对象,通过外源添加Al3+溶液,研究了Al3+胁迫对茶园土壤微生物区系及生理群的影响。结果表明,茶园土壤中的不同种类的微生物对Al3+的敏感性不同,Al3+添加量升至0.8 g/kg时,放线菌、真菌有一定的耐受性,而细菌数量呈快速下降趋势,亚硝化细菌几乎不能成活,但随着Al3+添加量的进一步升高,放线菌数量呈快速下降趋势,细菌数量则下降趋缓,而真菌相对能耐受较高浓度的Al3+;茶园酸性土壤中的微生物的绝大多数种类都面临低pH和Al3+的双重毒害;提高茶园土壤pH有利于活性Al3+向固定态转化,既能缓解低pH的不利影响,也解除了Al3+的毒害。改良茶园土壤酸性环境,是提高茶园土壤土著微生物数量和活性的较好方法之一。

The stimulation experiments of adding Al3＋ to tea garden soil were conducted to investigate the effect of Al3＋ on physiological groups of microorganisms in soil.The results showed that different kinds of microorganisms had different sensitivity to Al3＋.Actinomycetes and fungi presented certain Al3＋ tolerance when the concentration of Al3＋ was lower than 0.8g/kg;while the number of bacteria was declined significantly.Nitrosobacteria was most sensitive to Al3＋ for it could hardly survive when Al3＋ was increase to 0.8g/kg.With the further increasing of Al3＋ concentration,the number of bacteria was kept stable while actinomycetes presented the sharply decline.Compared with other microorganisms,fungi bad better tolerance to Al3＋ and it could live under higher Al3＋ concentration.Generally speaking,the microorganisms in acid soil of tea garden were poisoned by the low pH and Al3＋.Increasing the pH value of tea garden soil was befitted for the fixation of active Al3＋ and further mitigated the adverse impacts of Al3＋.So,changing the acid condition of tea garden soil was one of the perfect way to improve the quantity and activity of microorganisms in soil.