摘要： 为评估不同植物密度对鱼菜共生系统水质及鱼菜生长的影响，于2017年开展鱼菜共生试验。鲫鱼养殖水体有效体积350 L，养殖密度10 kg/m3；水雍菜栽培面积为1.0 m2，植物密度为60、45、30株/m2。结果显示：系统水温29.37℃~31.40℃，溶氧2.33~5.00 mg/L，pH 6.22~7.42，EC0.19~0.66 mS/cm，水质基本符合鱼菜生长需求；系统氨氮、亚硝酸盐氮、硝酸盐氮质量浓度随时间变化显著（P=0.000），不同处理组的硝酸盐氮质量浓度存在显著差异（P=0.028），且植物密度为45株/m2的系统其平均硝酸盐氮质量浓度最高；试验共持续33d，鱼总鲜重增量为（1.70±4.36）kg、（1.50±1.57）kg、（1.67±6.01）kg，菜总鲜重增量为（7.71±2.27）kg、（6.15±5.49）kg、（4.04±3.01）kg；植物密度对地上部分含氮量相对增长率的影响显著（P=0.037），且植物密度为45株/m2的系统其地上部分含氮量相对增长率为正值。研究表明，3种植物密度系统的鱼菜生长良好，植物密度为45株/m2组的系统具有较高的氮素转化效率，可通过扩大植物栽培面积来促进系统的氮素转化并获取更多的经济产出。

关键词: 鱼菜共生, 水质, 植物密度

Abstract: In order to evaluate the effects of different plant densities on water quality and growth of fish and vegetables in aquaponics system, an aquaponics experiment was conducted in 2017. The effective volume of water for Carassius auratus gibelio breeding was 350 L, and the breeding density was 10 kg/m3. The cultivated area of Ipomoea aquatica was 1.0m2, and the density was 60, 45 and 30 plants /m2. The results showed that when the water temperature was 29.37 - 31.40 ℃, the dissolved oxygen was 2.33 ~ 5.00 mg/L, pH was 6.22 ~ 7.42 and EC was 0.19 ~ 0.66 mS/cm, the water quality could basically meet the demand for growth of fish and vegetables. The mass concentration of system ammonia nitrogen, nitrite nitrogen and nitrate nitrogen changed significantly with time (P=0.000), the mass concentration of nitrate nitrogen in different treatment was significantly different (P=0.028), and the average mass concentration of nitrate nitrogen in the system with density of 45 plants /m2 was the highest. The experiment lasted for 33d, during which the total fresh weight of fish increased by (1.70±4.36) kg, (1.50 ± 1.57) kg, (1.67 ± 6.01) kg, and the total fresh weight of vegetables increased by (7.71 ± 2.27) kg, (6.15 ± 5.49) kg, (4.04 ± 3.01) kg. The effect of plant density on the relative growth rate of nitrogen content in the aboveground part was significant (P=0.037), and the relative growth rate of nitrogen content in the aboveground part in the system with density of 45 plants /m2 was positive. Studies have shown that fish and vegetables in the systems with three plant densities grew well, the system with density of 45 plants /m2 had higher nitrogen conversion efficiency, and the nitrogen conversion of the system and more economic output could be promoted by expanding the cultivated area of plants.

Key words: aquaponics, water quality, plant density