[Agricultural application of sludge dredged from landscape water bodies]

The feasibility and ecological effects of agricultural application of sludge dredged from the Grand Canal (Hangzhou Section) were studied. Applied too much dredged sludge to red soil and paddy soil affected the germination of alpine fescue [Fescuta ovina var. brachyphylla (Schult.) Piper] and colver (Trifolium repens. L) seeds, while there wasn't significantly affects in pot experiment. While the application rate was lower than 270 t.hm-2, the growth of pakchoi (Brassica chinensis L.) increased as application rate increasing. While the application rate was higher than 270 t.hm-2, the growth of pakchoi decreased. The flowers and grasses in garden were more suitable for the dredged sludge application, and there was significant increase of growth while the application rate was lower than 1080 t.hm-2. Contents of copper and zinc exceed hygiene standard, while the application rate was above 1350 t.hm-2. While the application rate was lower than 450 t.hm-2, the pollution of the groundwater had not been observed. The results showed that land application was an economical and feasible way for the disposal of sludge dredged from landscape water bodies, and horticultural application was more safe and economical than agricultural application.