Abstract: Because of the high acidity, low nutrients content, aluminum toxicity and potential heavy metals pollution, oil shale waste slag has negative effects on the normal growth of plants. A pot experiment with Tristania conferta, Schima wallichii, Vetiveria zizanioides and Paspalum notatum showed that after eight months growth on oil shale waste slag, the biomass of T. conferta, S. wallichii, P. notatum and V. zizanioides was decreased by 43.5%, 55.0%, 68.4% and 88.6%,respectively,compared with the control. The amendment of limestone increased the biomass of T. conferta by 3.1%, but that of S. wallichii, P. notatum and V. zizanioides was still decreased by 32.0%, 31.1% and 60.4%, respectively. There was a synergistic effect between acid stress and Al toxicity. Limestone amendment had better effects on mitigating the impact of oil shale waste slag, but the effects differed with different plant species.

Key words: Epiblema strenuana, Ambrosia artemisiifolia, Parthenium hysterophorus, Biocontrol of weed, Risk analysis