城市污泥和粉煤灰配施影响砂化土壤微生物区系的实验研究

目前,对利用城市污泥和粉煤灰改良土壤的研究大多集中在二者对土壤理化特性、作物产量以及重金属累积的影响等方面,而对土壤微生物区系进行研究的相对较少。为了了解城市污泥和粉煤灰改良砂化土壤对土壤微生物区系的影响,文章对包头试验田改良前后土壤微生物区系进行了比较,研究发现,刚刚改良后,土壤中微生物数量较对照组明显增加;在改良后的最初2个月内,细菌和放线菌的数量有所减少,真菌数量少量增加;改良后2～5个月内,改良后土壤中微生物数量较对照组增加幅度显著,细菌、放线菌和真菌数量分别增加79.53%～589.76%,46.53%～270%,61.92%～143.59%,且微生物数量增加的幅度随着时间的延长,呈上升的趋势。

EXPERIMENTAL STUDY ON IMPACTS ON MICROFLORA OF SANDY SOIL BY AMENDATION WITH SEWAGE SLUDGE AND COAL ASH

Most studies,using coal ash and sewage sludge(“two wastes”) to amend soil,were focused on the effects of coal ash and sewage sludge on soil physical and chemical properties,crop production,heavy metal accumulation and so on.While little effort was concentrated on their effect on soil microflora.To understand the effect of sewage sludge-coal ash on soil microflora,the authors studied the soil microbial number of amended soil at different stages.The experimental results indicated that the quantity of soil microbe increased obviously at the initial stage;the bacteria and actinomyces decreased and fungi increased slightly during the earlier two months after amended with“two wastes”;the bacteria,actinomyces and fungi increased up to 79.53%-787.88%,46.53%-270% and 61.92%-191.90% respectively in the sandy soil of the trial areas from the third to fifth month after amending.The increment amplitude showed a rising trend with time.