采用盆栽和田间实验,研究了不同浓度石油对玉米出苗率和幼苗叶绿素含量的影响,调查了土壤中石油初始质量浓度为10000mg·kg^-1时,对玉米生长性状、籽粒质量和土壤中微生物群落的影响,探讨了石油在玉米不同部位的残留量和不同时期土壤中石油含量变化。结果表明,土壤中石油初始质量浓度为3000、5000和10000mg·kg^-1时,幼苗叶片叶绿素含量依次减少1.7%、5.6%和11.3%,对玉米出苗率无显著影响。初始质量浓度为10000mg·kg^-1时,500d处理嗜油细菌数量高出对照94.4倍;石油污染处理的第1a,玉米株高、茎粗、地上生物量、根重、穗长、穗均粒数、百粒重和单株粒重较对照依次减少12.2%、14.3%、14.5%、15.5%、10.9%、4.4%、5.1%和6.2%,籽粒中粗脂肪、粗蛋白、淀粉含量分别下降5.8%、6.7%和7.2%,苯并[a]芘含量超过国家食品标准所规定的限量,玉米根、籽粒和穗芯中石油残留量较对照分别增加了4.77、3.82和0.29mg·kg^-1。在微生物、植物和自然条件的作用下,1a后石油对玉米生长的影响基本消除,2a后土壤中石油降解率达到95.5%,土壤中石油含量低于国家标准所规定的限量。
Both pot and field experiments were carried out to study the effects of petroleum with different concentrations on germination percentage and chlorophyll contents in the leaves of corn, the effects of 10 000 mg·kg^-1 petroleum-contaminated soil on microbial distribution in soil and the corn growth and seed quality, and the residual amount of petroleum in different parts of corn and the dynamics of petroleum contents in soil. The results showed that the chlorophyll content decreased by 1.7%, 5.6% and 11.3% at initial concentration of 3 000 mg·kg^-1, 5 000 mg·kg^-1 and 10 000 mg·kg^-1, respectively, while petroleum-contaminated soil did not affect the germination percentage of corn. The number of oil-degraded bacteria was 94.4 times more than that in the control after 500 days. Plant height, stem width, biomass, root dry weight, ear length, one ear-grain number, one hundred-grain weight and one ear-grain weight reduced 12.2%, 14.3%, 14.5%, 15.5%, 10.9%, 4.4%, 5.1% and 6.2% respectively. Crude grease, protein and starch contents in seed reduced 5.8%, 6.7% and 7.2%. BaP content in seed was 5.78 μg·kg^-1, higher than the state-required standard (5 μg·kg^-1). The effects of petroleum on corn growth could be eliminated after a year. The removal rate of petroleum reached 95.5% two years later, and the petroleum content in soil was lower than the state-required standard.