The invention relates to a method for improving an
eutrophic water body by planting vegetables on a water surface, which comprises the following steps of: (1) selecting
fresh water of which the
nitrogen content is more than or equal to 0.5 mg / L,
phosphorus content is more than or equal to 0.05 mg / L and
potassium content is more than or equal to 0.5 mg / L in a
water body; (2) enclosing a vegetable planting area; (3) arranging the vegetable planting area; (4) manufacturing a floating planting
bed; (5) selecting vegetable varieties; (6) planting vegetables; (7) managing, namely controlling the speed of
water flow according to the growth vigor of the vegetables and a detection result of
water quality, so that compared with a water inlet in the planting area, at a water outlet, the
total nitrogen content is reduced by 30 to 90 percent, the
total phosphorus content is reduced by 20 to 70 percent, and the
potassium content is reduced by 10 to 50 percent while the growth vigor of the vegetables is ensured; and (8) selecting the vegetable varieties which is suitable to be planted in different seasons, and planting in turn throughout the year. In the method, the
eutrophic water body is improved effectively by a biological cleaning method, and compared with physical and chemical means of managing the
eutrophic water body, the method has obvious effect and low
investment cost and is convenient to popularize and perform large-scale planting; and the vegetables are planted without applying
fertilizer and spraying pesticides, so a new
pollution source is not generated, and the planted vegetables reach the standard of green organic vegetables. By the method,
resource utilization is maximized, and vegetable baskets of people are abundant while the eutrophic
water body is managed. The production management and monitoring are convenient, so the method is particularly suitable for the large-scale planting.