Abstract:

In order to better understand the bioremediation efficiency and its mechanism of co-cropping systems in agricultural soils contaminated by POPs (persistent organic pollutants), a greenhouse experiment under both single cropping and intercropping conditions with 3 plants including pumpkin (Cucurbita moschata), soybean [Glycine max (L.) Merr.] and maize (Zea mays L.) were conducted in a PCB contaminated lateritic red soil. The results indicated that the phytoremediation was good to the degradation of PCB in the soil and the co-cropping. The PCB concentration in the soil of monocropping was 70.25%-92.11% of control. The soil biodegradation of PCB was significantly enhanced under intercropping conditions with PCB concentration of 61.44%-80.53% of control. Especially, it’s the best effect in a soybean-maize intercropping system, significantly lower than control. In addition, accumulation of PCB in aboveground of all plants complied with the limit values of China Food Safety Standards. Under different cropping patterns, the fluorescein diacetate (FDA), dehydrogenase (DHO), catalase (CAT) and Eh, C/N had significant differences with control. From the correlation analysis, it showed that the PCB concentration in soil had extremely significant negative correlation with fluorescein diacetate (FDA), dehydrogenase (DHO), catalase (CAT) and C/N, and significant negative correlation with polyphenol oxidase (PPO) and Eh.