中文摘要：

采取野外田间原位修复方式，研究经济作物和修复植物单作和间作模式修复多环芳烃污染农田土壤的效果。结果显示，在各试验处理中，玉米／苜蓿间作及玉米／黑麦草间作修复效果均略低于苜蓿单作和黑麦草单作的，但是，从农业生产经济效益角度来看，玉米／苜蓿间作及玉米／黑麦草间作具有较大的农业经济效益。玉米／苜蓿间作及玉米／黑麦草间作处理对土壤PAHs总量的降解率分别达到了25％-30％，其中高环PAHs的降解率分别达到了26％～35％。这两个处理土壤微生物数量较多，其中细菌、真菌和放线菌的数量分别为9×10^6～12×10^6CFU·g^-1、7×10^4～9×10^4CFU·g^-1和4×10^5～14×10^5CFU·g^-1，同时，PAHs降解菌数量均高于其他试验处理，达到1．3×10^5—1．8×10^5MPN·g^-1，占细菌总数的6％-8％，是其他处理的2—3倍。修复植物苜蓿或黑麦草和经济作物玉米间作模式在不影响农业生产的前提下，显著提高了土壤PAHs的降解率，在污染农田土壤修复过程中有着广阔的应用前景。

英文摘要：

The paper is aimed to present its author＇s experimental results of the effects of the application of intercropping system to remedy the farming soil contaminated by the polycyclic aromatic hydro- carbons （PAHs）, one of the most widespread organic pollutants distributed primarily in the soil, sediment and oil-residues. To remove the aged PAHs from the farming soil, we have done experiments with phytoremediation in-situ to study the effect of mono-cropping and intercropping treatments on the removing. Some economic crops and remediation crops, such as maize, castor, soybean, ryegrass and alfalfa, have been used in our experiments. The results of our experiments show that the removing rate of PAHs stands between 25 % and 30%, whereas the removing rate of high rings PAHs can be as high as between 26% and 35% in maize/alfalfa intercroping and that of maize/ryegrass, which proves significantly higher than done by means of other treatments. At the same time, maize/alfalfa and maize/ryegrass intercropping proves to be able to increase the amount of soil microbes, with their amount of bacterium, fungi and actinomycete in soil going up as follows： 9 × 10^6 - 12 × 10^6 CFU·g^-1, 7 × 10^4 - 9 × 10^4 CFU·g^-1 and 4× 10^5 - 14 × 10^5 CFU·g^-1, respectively. More- over, the greatest increase has been gained in the account of PAHs- degrading bacteria from the two treatments, that is, 1.3 × 10^5 - 1.8 × 10^5 cell·g^-1, and occupied 6% - 8% in the total amount of bacteria in the soil, thus greatly enhancing the crops-microbial interaction as a result of improvement of the remediation to the soil PAHs pollution under the new intercropping system. Furthermore, the improved interaction of root and soil tends also to influence the bioavailability of PAHs. In addition, the pollutant removing effect in the contaminated soil can also be enhanced by such potential application. Hence, the results of our experiments suggest the feasibility of the multi-species phytoremediation to improve the remediation effects of PAHs,