Abstract: The effects of single and compound action of different levels of selenium and cadmium on the radish growth and the absorption of selenium and cadmium were investigated using a pot experiment. The results showed that a moderate amount of selenium (2.5-5.0 mg·kg^-1) promoted the growth of radish (43%), representing increases in the germination percentage, the SPAD value of leaf (22%), and biomass of radish (50%). The single pollution of cadmium significantly inhibited the growth of radish (P<0.05). Selenium with a content in the soil below 1.5 mg·kg^-1 had an antagonistic action on the effect of cadmium less than 5.0 mg·kg^-1, and promoted the growth of radish. The selenium content in radish increased with the increase in level of selenium in the soil and the enrichment of selenium in radish was obvious. The selenium absorption in the underground parts of radish was greater than in the aboveground parts. When the selenium content in the soil was below 5.0 mg·kg^-1, the presence of cadmium with the content of 5.0 mg·kg^-1 did not affect the selenium absorption of radish. Although the presence of cadmium affected the selenium absorption of radish when the selenium content in the soil ranged from 5.0 to 10.0 mg·kg^-1, the selenium content in radish was still in a steady accumulation. When the selenium content in the soil was above 10.0 mg·kg^-1, the presence of cadmium inhibited the selenium absorption of radish, which was more obvious for the aboveground parts than for the underground parts. Selenium significantly reduced the cadmium absorption of radish, which was more obvious for the underground parts than for the aboveground parts. Hence planting seleniumrich radish in soil with light cadmium pollution could not only produce safe, nutritious and selenium-rich food, but also realize the reuse of polluted croplands.

Key words: available nitrogen, biological soil crusts, simulated grazing, total nitrogen, microbial biomass nitrogen