Research has showed that the concentrate generated during the process of treating landfill leachate by membrane bio-reactor coupled with nanofiltration could be used to produce a humic substances-containing water-soluble fertilizer(HSWF). In this paper, a hydroponic experiment was conducted to investigate the effects of HSWF on seed germination and seedling growth of cucumber, cabbage, lettuce and perennial ryegrass. Results show that HSWF at original or low dilution had significant inhibition effects on seed germination of all crops tested, with lettuce being the most sensitive. However, such inhibition disappeared when the fertilizer was diluted at more than 20 times. The length and weight of all crops were inhibited by high concentrations, but enhanced by low concentrations of HSWF. The fertilizer showed greater inhibition to the root length than shoot length, as well as to seedling growth than seed germination. The optimum concentrations of the fertilizer for promoting crop growth ranged from 10 to 25 time dilution depending on crops. The promoting effect of the fertilizer was cucumber>cabbage and lettuce>perennial ryegrass.
Journal of Agro-Environment Science( J. Agro-Environ. Sci.)