中水灌溉对城市绿地土壤微生物数量的促进效应

Promotion Effect of Recycled Water Irrigation on Microorganism Quantity in Urban Greenspace Soil

用田间采样及室内培养的方法,研究短期和长期中水和清水灌溉下3种常见绿地植物根系层土壤微生物的数量变化。结果表明:金叶假连翘和黄金榕的根际土壤细菌、真菌和放线菌数量均随土层深度的增加而减少,但真菌在短期清水灌溉下20～40 cm土层中数量分布最多;台湾草的根际土壤细菌、真菌在各土层间的数量分布与金叶假连翘和黄金榕相似,放线菌在20～40 cm土层数量分布最多;与清水灌溉相比,3种植物在短期中水灌溉下,其根际土壤细菌、真菌和放线菌数量在0～20 cm土层差异显著,20～40、40～60 cm土层中的数量分布因植物种类不同而有所差异。

Using the methods of field sampling and laboratory incubation, the change of microorganism quantity in the root layer soil of three common greenspace plant species irrigated by both clean and recycled water for the short-term and long-term duration was studied. The results showed that the quantity of bacteria, fungi, actinomycetes in the rhizosphere soil of Duranta repens and Ficus microcarpa decreased as soil depth increased, but the quantity of fungi was the most in 20 -40 cm soil layer irrigated by clean water for short-term. The quantitative distribution of bacteria and fungi in the rhizosphere soil of Zoysia pacifica was similar to that of in the rhizosphere soil of Duranta re- pens and Ficus microcarpa, but the quantitative distribution of actinomycetes was the most in 20 -40 cm soil layer. Compared with clean water irrigation, the quantitative distribution of bacteria, fungi, actinomycetes in the rhizosphere soil of Zoysia pacifica, Duranta repens and Ficus microcarpa that irrigated by recycled water increased evidently, and there were significant differences in the quantity of microorganisms in the 0 -20 cm soil layer. The quantitative distri- bution of the microorganisms in the 20 -40 cm and 40 -60 cm soil layers varied with different plant species.