陕北黄土区土壤石油污染物对玉米生长影响研究

摘要

为研究陕北黄土区土壤石油污染物对玉米种子出苗率和幼苗生长的影响,采用盆栽试验的方法,设置土壤不同石油浓度处理组,培养玉米2个月,测定了各处理组玉米的出苗率、株高、茎宽、生物量和叶片叶绿素浓度.结果表明:(1)土壤石油质量浓度即使为30 g/kg时,各处理组出苗率最终均为100％;土壤石油质量浓度达到20 g/kg及以上时,在一定程度上会推迟玉米种子的出苗时间.(2)土壤石油质量浓度达到1 g/kg就会对玉米茎的生长产生抑制作用,可以显著降低玉米株高,但对玉米茎宽影响不显著.随着土壤石油浓度的升高,对玉米株高的抑制作用显著增加.玉米茎宽总体上是随着土壤石油浓度的升高而减小,但土壤石油质量浓度为0～1g/kg或20～30 g/kg时,玉米茎宽没有显著差异.(3)当土壤石油质量浓度达到5 g/kg以上时,植株干质量随石油浓度升高而减少.土壤石油质量浓度达到20 g/kg时,会显著降低玉米根的含水率;达到30 g/kg时,会显著降低茎和叶的含水率.(4)土壤石油质量浓度为1、5 g/kg时,叶绿素a和叶绿素b浓度与土壤石油质量浓度为0 g/kg时没有显著差异;土壤石油质量浓度为10、20、30 g/kg时,叶绿素a和叶绿素b浓度显著低于土壤石油质量浓度为0 g/kg时,并且随土壤石油浓度的升高呈降低趋势.%Series of pot tests were applied to investigate the effecf of petroleum in north Shaanxi loess region soil on seed germination rate and seeding growth of maize. In the experiments, the maize was cultivated in soils which con taining different concentration of petroleum for 2 month,the seed germination rate,plant height and stem widths,bio mass and leaf chlorophyll- content were determined. Results showed that the seed germination rate of all treatment groups were, 100% even the concentration of the petroleum in soil was 30 g/kg. The germination time of maize seed would be delayed if the petroleum content of soil was more than 20 g/kg. Petroleum showed an inhibition influence to the growth of maize.it could decrease the plants' height of maize, but had little effect on stem widths. The inhibition effect was significantly increased with increasing the petroleum concentration. The stem widths of maize presented an overall decrease tendency, when increasing the petroleum concentration. The petroleum content of 5 g/kg or more will decrease the dry weight of plants. When petroleum concentration reached to 20 g/kg,moisture rate of maize root de creased obviously; when petroleum concentration reached to 30 g/kg,moisture rate of maize steam and leaf was signif icantly decreased. Compared with the control group, the contents of chlorophyll a and chlorophyll b had little difference when the petroleum concentration was lower than 5 g/kg, while the contents of chlorophyll a and b dropped rapidly when the petroleum content more than 10 g/kg.