关键词: 鱼塘, 植莲, 环境效益, 经济效益, 长江中游

Abstract:

The continuous operation of pond fish culture with chemical fertilizers for several years in wetlands of the middle reaches of the Yangtze River resulted in the accumulation of nitrogen and phosphorus in pond sediments. An experiment of planting lotus 〖WTBX〗(Nelumbo nucifera)〖WTBZ〗 was conducted in 2004 in three fertilized fish ponds in Zhangduhu Fish Farm， located in the central part of the Yangtze River Basin，China. The purpose of this experiment was to evaluate the effectiveness of nitrogen and phosphorus removal from fertilized fish ponds by lotus， and to analyze the economic revenue of planting lotus. Nitrogen and phosphorus removals were calculated through input and output data. Economic analysis was based on cost and income. Physical and chemical parameters in water and total Kjeldahl nitrogen (TKN) and total phosphorus (TP) in the surface (0～5 cm)， middle (5～10 cm) and bottom (10～50 cm) layers of sediment were measured monthly from April to October.The results indicated that the concentrations of TKN and TP in the three layers of sediments decreased significantly (〖WTBX〗P〖WTBZ〗<005) after planting lotus；every hectare of lotus could remove (mean±SD) 1 50938±2211 kg nitrogen and 188995±282 kg phosphorus from old fertilized fish ponds from April to October；every hectare of lotus could make an average of 52 031±1 579 Chinese Yuan in revenue. The present experiment has demonstrated that planting lotus in fish ponds could be environmentally and economically effective.

Key words: fish ponds, planting lotus, environmental effectiveness, economic effectiveness, the middle reaches of the Yangtze River