4种浮床植物吸收水体氮磷能力试验研究

选取美人蕉、黄菖蒲、再力花和千屈菜4种常见植物作为研究对象，建立淀山湖富营养化防治植物浮床试验工程，对其生长特性和氮磷吸收能力进行试验研究. 结果表明，采用上下层尼龙网固定种植方式有利于浮床植物的快速生长繁殖，美人蕉和再力花的成活率均为83.33%，高于千屈菜的76.67%和黄菖蒲的53.33%. 11月收割时美人蕉和再力花的分蘖数分别达到64株和78株，生物量（鲜重）分别为32.0 kg/株和38.6 kg/株. 美人蕉和再力花体内氮磷含量分布均为茎叶>根系，美人蕉茎叶和根系单位干物质量中氮、磷含量比分别为1.40和1.21，再力花则分别为1.59和1.08. 植物体内的氮磷累积量差异主要来自于生物量的差异，再力花对氮的吸收能力最强，收割时氮获得量达到457.11 g/m²，美人蕉对磷的吸收能力最强，收割时磷获得量达到41.29 g/m²，美人蕉茎叶氮、磷吸收量分别为根系的2.17倍和1.86倍；再力花分别为1.73倍和1.17倍. 美人蕉和再力花可以作为淀山湖水体富营养化防治的浮床栽培备选植物来进行推广应用.

Study on the Nitrogen and Phosphorus Uptake Ability of Four Plants Cultivated on Floating-bed

Plant floating-bed tested engineering was constructed for eutrophication control in Dian-shan Lake, the characteristics and nutrient uptake abilities of Canna indica, Iris pseudacorus, Thalia dealbata and Lythrum salicaria were compared. It shows that using upper and lower nylon nets to fix the plants on the floating-bed is beneficial for them to grow and reproduce rapidly. Survival rates of Canna indica, lris pseudacorus, Thalia dealbata and Lythrum salicaria are 83.33%, 83.33%, 76.67% and 53.33% respectively. Ramets of Canna indica and Thalia dealbata are 64 and 78 respectively in November, and the biomass (fresh weight) of these two plants are 32.0 and 38.6 kg per individual plant. Nitrogen (N) and phosphorus (P) content in stems/leaves of Canna indica and Thalia dealbata are greater than those in roots. The ratio between stems/leaves and roots of N, P content in Canna indica are 1.40 and 1.21 respectively, while 1.59 and 1.08 in Thalia dealbata. The difference of cumulative N, P content in plants is mostly on account of different plant biomass. N uptake ability of Thalia dealbata is the highest, which is 457.11 g per square; Canna indica has the highest P uptake ability, which is 41.29 g per square. N, P uptake ability of stems/leaves in Canna indica are 2.17 and 1.86 times higher than that of roots, while 1.73 and 1.17 times higher respectively in Thalia dealbata. Thus, Canna indica and Thalia dealbata are recommended as the floating-bed plants to control the eutrophication in Dian-shan Lake.