摘要:为研究植物残体配合施氮对石油污染土壤生物学和化学性质的综合修复能力，以紫花苜蓿（Medicago sativa）、铁杆蒿（Artemisia gmelinii）和小冠花（Coronilla varia）3种广泛分布于陕北石油污染区的草本植物凋落物为对象，分别在配合施氮调节土壤C：N为25：1和不配合施氮的条件下，将其与45.37 g/kg的重度石油污染土壤混合，在20-25℃、恒湿条件下进行为期180 d的室内修复试验，检测上述处理对油污土壤微生物数量、11种土壤水解酶和氧化还原酶活性以及速效N、P和K含量的影响。结果表明：（1）3种凋落物处理均可显著提高污染土壤中放线菌和真菌数量，蔗糖酶、淀粉酶、纤维素酶、木聚糖酶、脲酶、蛋白酶、磷酸酶、多酚氧化酶、过氧化氢酶和过氧化物酶活性以及速效养分含量，并显著降低土壤总石油烃含量。（2）配合施氮总体上显著强化了凋落物对污染土壤生化性质的修复作用，但对凋落物处理下木聚糖酶、脲酶、蛋白酶和脱氢酶活性和微生物数量的恢复可能产生不利影响。（3）单纯使用凋落物作为调理剂可以更为全面的修复油污土壤受损生化性质，具有高N和P含量、较低C/N、C/P比以及较低多酚和木质素含量的凋落物修复效果更好。在急需迅速修复土壤的条件下，配合适量施氮可作为强化凋落物修复效果的可选途径，但应注意其导致的部分土壤生化指标修复效果的降低。



Abstract:Litters of 3 types of grasses including Medicago sativa, Artemisia gmelinii, and Coronilla varia were mixed with 45.37 g/kg petroleum-contaminated soil with or without urea fertilization (the C:N of soil was adjusted to approximately 25:1) in the study. We aim to investigate the effects of plant litters and nitrogen fertilization combination on remediation of petroleum-contaminated soils. The mixtures were incubated at 20-25℃ with consistent soil moisture for 180 days. The microbial populations, the activities of 11 types of hydrolases and oxidoreductases, and contents of available N, P and K in soils were determined to analyze the individual or the combined effects of plant litter and urea on the bio-chemical properties of petroleum-contaminated soils. The results indicated that (1) all types of grass litters tested here significantly increased the populations of actinomycetes and fungi, the activities of sucrase, amylase, carboxymethyl cellulase, xylanase, urease, protease, alkaline phosphatase, polyphenol oxidase, catalase and peroxidase, and the contents of available N, P and K in petroleum-contaminated soils, while they significantly accelerated the degradation of total petroleum hydrocarbons. (2) Generally, urea application facilitated the remediation of grass litters on petroleum-contaminated soils. However, it might impair the positive effects of litter treatments on the activities of xylanase, urease, protease and dehydrogenase, and the microbial populations in petroleum-contaminated soils. (3) Sole litter treatment could remarkably improve the biochemical properties of petroleum-contaminated soils, especially with high N and P contents, lower C/N, C/P ratios, low lignin and polyphenols contents litters. In the case that the remediation was exigent, appropriate urea fertilization could be a feasible approach to accelerate the remediation effects of grass litters on petroleum-contaminated soils, whereas taking its negative effects on above-mentioned biochemical soil properties in account.





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