景观水体疏浚底泥的农业利用研究

Agricultural application of sludge dredged from landscape water bodies.

对运河 (杭州段 )疏浚底泥土地利用的可行性及其生态影响进行了研究 .实验室发芽率测定表明 ,土壤中大量掺入疏浚底泥对种子发芽率有一定的影响 ,但在盆栽中影响很小 .疏浚底泥田间投放量在 2 70t·hm-2 以下 ,对青菜的生长具有促进作用 ,超过 2 70t·hm-2 以上用量对青菜产量有一定影响 .与青菜相比 ,草坪草、园艺花卉对底泥投放量具有更大的耐性 ,表现出明显的促进生长现象 .底泥用量在 10 80t·hm-2 以下时青菜中Cu、Zn含量均未超过食品卫生标准 ,用量为 135 0t·hm-2 时则均超过了标准 .原状土柱淋洗实验发现底泥用量在 4 5 0t·hm-2 以下未造成地下水污染 ,表明运河底泥直接土地利用较一般污水污泥堆肥的危害更小 ,园林投放比农田投放具有更大的可行性 。

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.