长江中游典型鱼塘植莲的环境与经济效益分析

长江中游湿地区域的池塘经过连续多年的化肥养鱼导致了大量的氮、磷沉积在鱼塘底泥中。分析了鱼塘植莲对养殖后沉积的氮、磷的重新利用及植莲的经济效益。实验于2004年在位于长江中游的武汉市涨渡湖渔场进行。根据收支平衡计算了实验池氮、磷的转移量，根据投入产出计算了实验池的经济收入。逐月分析了池塘中水质理化指标和底泥中总凯氏氮（TKN）和总磷（TP）的含量。方差分析表明：总凯氏氮、总磷在池塘底泥表层（0～5 cm）、中层（5～10 cm）和底层（10～50 cm）当中的含量都出现显著性降低(〖WTBX〗P〖WTBZ〗<005)。养鱼池塘通过植莲后，每公顷有1 50938±2211 kg氮和188995±282 kg磷被重新利用；鱼塘植莲产生的经济效益平均为每公顷52 031±1 579元。实验表明鱼塘植莲既能够有效地改善池塘养殖的生态条件，又能带来较高的经济收入，是长江流域湿地保护和综合利用的一种高效的农业生态模式。

ANALYSIS OF ENVIRONMENTAL AND ECONOMICAL EFFECTIVENESS IN PLANTING LOTUS IN TYPICAL FISH PONDS IN AREAS ALONG THE MIDDLE REACHES OF THE YANGTZE RIVER

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.