Effect of Ipomoea aquatica Floating-bed on the quantity and distribution of nitrogen cycling bacteria and nitrogen removal Accumulation of di-(2-ethylhexyl) phthalate in various genotype Ipomoea aquatica-paddy soil system A preliminary study on the effect of municipal sludge on crop seed germination and seedling growth Chemical characteristics of the rhizosphere soil of water spinach cultivars differing in Cd accumulation.