Vvv 要
本试验以鱼–菜共生和生物絮团水质调控技术为理论基础，池塘设置不同覆盖率(5%和10%)的水蕹菜浮床，通过定时监测水质和浮游生物变化，探讨了水蕹菜浮床对水质和浮游生物的影响；向池塘添加理论添加量100%、75%和50%的碳源(糖蜜)，通过定时监测水质和浮游生物变化，探讨了碳源(糖蜜)添加对水质和浮游生物的影响以及确定了碳源(糖蜜)的适宜添加量，旨在为鱼–菜共生和生物絮团水质调控技术在西北地区盐碱池塘的推广应用提供一定的技术参考和理论依据。主要结果如下：
(1) 在池塘置入水蕹菜浮床后，水体透明度明显提高，DO水平保持在3 mg/L以上，但对水温、pH和电导率的影响较小；浮床水蕹菜对水体NH4+-N、NO3--N、NO2--N、TN、TP以及COD的最大去除率分别为58.2%、34.8%、53.8%、9.46%、39.3%和31.3%，整个试验期间设置浮床的试验池塘水体NH4+-N、NO3--N、NO2--N、TN、TP和COD含量平均值均显著低于对照塘(P<0.05)。
试验塘浮游植物密度、生物量和浮游动物密度均显著低于对照塘(P<0.05)，但浮游动物生物量显著高于对照塘(P<0.05)；试验塘浮游植物Shannon-Weaver多样性指数H和Pielou均匀度指数J均显著高于对照塘塘(P<0.05)，浮床覆盖率为10%的试验塘浮游动物Shannon-Weaver多样性指数H和Pielou均匀度指数J显著高于对照塘(P<0.05)。
不同覆盖率的水蕹菜浮床均可有效改善水质，但10%覆盖率的浮床对水质的改善效果较5%覆盖率的浮床好。
(2) 添加不同量的糖蜜均可提高水体透明度、降低COD，但对TP含量无显著影响。糖蜜添加量100%、75%和50%的3口试验塘水体NH4+-N、NO3--N和NO2--N含量较对照塘分别降低58.20%、77.48%、39.81%和25.71%、31.42%、21.92%以及52.94%、76.19%、47.82%，差异显著。
糖蜜添加对池塘蓝藻影响较明显，试验塘蓝藻密度和生物量分别为(812.5～1263.0)×104 ind./L和25.34～54.31 mg/L，对照塘蓝藻密度和生物量分别为(1079.2～1216.5) ×104 ind./L和34.01～58.54 mg/L，差异显著(P<0.05)。糖蜜添加
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Vvv 量100%和75%的池塘浮游动物Shannon-Weaver多样性指数分别下降15.18%和16.83%，显著低于对照塘32.56%的下降速度(P<0.05)。
综合认为，池塘中添加理论量100%和75%的糖蜜均可降低有害物质浓度、限制蓝藻的大量增殖、提高浮游生物多样性或减缓其下降速度，达到活化水体、改善水质的效果，认为添加理论量75%的糖蜜更经济实用。
关键词：盐碱池塘；水蕹菜浮床；生物絮团；糖蜜；水质；浮游生物
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Vvv Summary
To study the effects of Ipomoea aquatica floating-bed and adding carbon resource (molasses) on water quality and plankton of the saline-alkaline ponds in the northwest China in fish-vegetable and bio-floc technology. We have conducted different coverage rate of Ipomoea aquatica floating-bed (5% and 10%) on two treatment fish ponds, and added the molasses 100%, 75% and 50% of the theoretical added amount to three treatment fish ponds from May to September, aimed at providing some technical reference and basic information of this two technologies applicated in saline-alkaline ponds in the northwest of China. The main results are summarized as follows:
(1) With the Ipomoea aquatica floating-bed building in ponds, the transparency of the water was inproved obviously, made dissolved oxygen stayed at above 3 mg/L, but have less impact on temperature, pH value and electrical conductivity in ponds. The highest removal rate of NH4+-N, NO3--N, NO2--N, TN, TP and COD in treatment ponds was 58.2%, 34.8%, 53.8%, 9.46%, 39.3% and 31.3%, respectively. The average concentration of NH4+-N, NO3--N, NO2--N, TN, TP and COD in treatment ponds were both significantly (P<0.05) lower than the control pond.
The density and biomass of phytoplankton, the density of zooplankton in treatment ponds were both significantly (P<0.05) lower than the control pond, but the biomass of of zooplankton was significantly (P<0.05) higher than the control pond. The Shannon-Weaver diversity and Pielou evenness index of phytoplankton were both significantly (P<0.05) higher than the control pond. The Shannon-Weaver diversity and Pielou evenness index of zooplankton in treatment 10% pond was significantly (P<0.05) higher than the control pond.
Different coverage rate of Ipomoea aquatica floating-bed can effectively improved the water quality, but the treatment 10% was better than the treatment 5%.
(2) Adding different amount of molasses to ponds could improve the transparency of the water, reduce the value of COD, but had no significantly impact
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Vvv on the concentration of TP of the water. The concentration of NH4+-N, NO3--N, NO2--N of three treatment ponds decreased respectively by 58.20%、77.48%、39.81% and 25.71%、31.42%、21.92% and 52.94%、76.19%、47.82%, which was significantly different.
The density of cyanobacteria in treatment ponds ranged from 812.5×104 to 1263.0×104 ind./L and the biomass ranged from 25.34 to 54.31 mg/L, correspondingly, the density of cyanobacteria in control pond ranged from 1079.2×104 to 1216.5×104 ind./L and the biomass ranged from 34.01 to 58.54 mg/L, which was significantly (P<0.05) different. The Shannon-Weaver diversity of zooplankton of treatment 100% and 75% decreased by 15.18% and 16.83%, and it was significantly (P<0.05) lower than the control pond which decreased by 32.56%.
Adding with 100% and 75% of the theoretical amount of the molasses to pond, the concentration of some harmful substances decreased，cyanobacteria reproduction controlled, the biodiversity of plankton increased, the water quality could be improved effectively, the treatment adding molasses with 75% of the theoretical added amount is more economical and practical.
Key words：saline-alkaline ponds; Ipomoea aquatica floating-bed; biological floc; molasses; water quality; plankton
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