Abstract:

A pot experiment was carried out on effects of application of organic manure as base fertilizer on plant morphology and leaf physiology of the potato growing in the soil under lead (900 mg·kg^-1) and cadmium (5 mg·kg^-1) stresses and on rhizospheric soil enzyme activity for exploration of effects of organic manure mitigating harm of Pb and Cd to the plant. Results of the experiment show:(1) basal application of organic manure promoted growth of the potato growing in the soils polluted with Pb and Cd, and at the tuber maturing stage, urease, catalase and invertase in the rhizosphere of the plant increased by 70.9%, 5.6% and 58.6%, respectively, in activity, and furthermore, superoxide dismutase (SOD) did by 4.7% in activity and chlorophyll content by 9.6% in leaves of the plant as compared with that in the soils without application of organic manure; (2) in the soil under combined pollution of lead and cadmium, basal application of organic manure reduced the activity of SOD by 12.7% and 8.4%, and the content of chlorophyll by 4.1% and 14.7% in leaves of the plant at the maturing stage as compared, respectively, with that of the plant in the soils polluted with lead and cadmium, separately; and (3) basal application of organic manure increased the plant in polluted soils by 32.7% and 40.8% in plant height and yield, respectively, over the plants in the soils without application of organic manure, and reduced mean accumulation of lead and cadmium in tuber by 87.4% and 16.7%, respectively. The pot experiment demonstrates that basal application of organic manure is obviously effective in mitigating the stresses of lead and cadmium to potato.

Key words: lead and cadmium compound pollution, organic manure, potato, enzyme activity