Abstract：
With developments in industry, petroleum and heavy metal pollution are increasingly affecting soil, significantly harming the environment, biosecurity, and human health. Therefore, the remediation of contaminated soil is becoming increasingly important. In this study, ryegrass (Lolium perenne L.) was planted in petroleum-heavy metal co-contaminated soil with the application of nitrogen and phosphorus fertilizers. Three treatments were set up: uncontaminated soil + ryegrass (SH); petroleum-heavy metal co-contaminated soil + ryegrass (SPGH); and petroleum-heavy metal co-contaminated soil + ryegrass + nitrogen and phosphorus fertilizer (SPGH + NP). The results showed that the petroleum-heavy metal co-contamination promoted increases in the root length, surface area, volume, and diameter of ryegrass roots, increasing the below-ground biomass and decreasing the photosynthetic pigment content in the early stages of the experiment. The ratios of chlorophyll a/b and chlorophyll/carotenoid also increased. However, the application of fertilizer reduced the length, surface area, volume, and diameter of ryegrass roots in the co-contaminated soil, and the below-ground biomass decreased while the above-ground biomass increased. Furthermore, the photosynthetic pigment content was significantly higher than that in the unfertilized treatment and the chlorophyll a/b ratio decreased while the chlorophyll/carotenoid ratio increased. Therefore, fertilizers could alleviate the toxic effects of petroleum-heavy metal combined pollution on ryegrass roots and promote the synthesis of chlorophyll and other pigments, thus reducing the inhibitory effect of petroleum-heavy metal combined pollution on ryegrass growth and facilitating the remediation of the polluted soil.
摘要：
随着工业的发展，石油和重金属污染对土壤的影响越来越大，严重损害环境，生物安全,和人类健康。因此,污染土壤的修复变得越来越重要。在这项研究中,黑麦草（LoliumperenneL.）种植在石油-重金属共污染的土壤中，并施用氮磷肥料。建立了三种处理方法：未污染的土壤黑麦草（SH）；石油-重金属共污染的土壤黑麦草（SPGH）；和石油-重金属共污染的土壤黑麦草氮磷肥（SPGHNP）。结果表明,石油-重金属共污染促进了根长的增加,表面积,volume,和黑麦草根的直径，在实验的早期阶段增加地下生物量并降低光合色素含量。叶绿素a/b和叶绿素/类胡萝卜素的比率也增加。然而,肥料的施用减少了长度，表面积,volume,和共同污染土壤中黑麦草根的直径，地下生物量减少，而地上生物量增加。此外，光合色素含量明显高于未施肥处理，叶绿素a/b比降低，叶绿素/类胡萝卜素比增加。因此,肥料可以减轻石油-重金属复合污染对黑麦草根系的毒性作用，促进叶绿素和其他色素的合成，从而降低石油-重金属复合污染对黑麦草生长的抑制作用，促进污染土壤的修复。
