油页岩废渣对植物生长的影响及石灰改良效应

Impact of oil shale waste slag on plant growth and benefits of limestone amendment

油页岩废渣因酸度高,养分含量低,并存在一定程度的铝毒和重金属污染等,使得植物很难在其中正常生长发育。通过盆栽实验方法,对红胶木、红荷木、香根草和百喜草等4种植物在油页岩废渣及石灰改良后的废渣中的生长状况进行了观测。结果表明,4种供试植物直接种植在废渣中均受严重胁迫,它们的生物量均急剧下降。与对照土壤相比,种植8个月后,红胶木的生物量下降了43·5%,红荷木下降了55·0%;草本植物降低的更多,百喜草为68·4%,香根草为88·6%。而在经过石灰改良的废渣中,4种植物的生物量较对照土壤相比,红胶木的生物总量不但没有降低,反而较对照增加了3·1%,显示该植物不再受酸性废渣的胁迫,而红荷木、百喜草和香根草的生物量分别下降了32·0%、31·1%和60·4%,表明,这3种植物均遭受一定程度的胁迫。总的来看,酸性胁迫与铝毒害有协同作用,石灰对油页岩废渣的改良效果较明显,但对不同的植物而言,改良效果又存较大差异。

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 notaturn 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 A1 toxicity. Limestone amendment had better effects on mitigating the impact of oil shale waste slag, but the effects differed with different plant species.