浮床空心菜种植比率对养殖池塘的水质和青虾生长的影响

Effect of Floating Bed Planting Ratio of Water Spinach Ipomoea aquatica on Aquaculture Pond Water Quality and Growth of Oriental River Prawn Macrobrachium nipponense

摘要: 本文探讨了占不同水面比率的浮床空心菜对养殖池塘水质净化和青虾生长的影响。试验是在青虾放养密度均为40 ind./m²的8口面积相等的土池进行，共设3个处理组，处理1组(TR1)为浮床空心菜种植占池塘面积的6.7%，处理2组(TR2)为浮床空心菜种植占池塘面积的13.5%，处理3组(TR3)为浮床空心菜种植占池塘面积的27%，对照组为无空心菜浮床的2口池塘。经3个半月(105 d)的养殖试验结果表明，通过种植空心菜浮床的3个处理组的青虾增重率和特定生长率均高于对照组；种植空心菜浮床的3个处理组青虾成活率、亩产量和体重规格均显著高于对照组(P < 0.05)，3个处理组的青虾饲料系数显著低于对照组(P < 0.05)，但处理组之间的成活率、亩产量、体重规格和饲料系数差异不显著(P > 0.05)。水质检测分析数据结果表明，在相同的环境条件和管理方式下，种植空心菜的3个处理组青虾养殖的池塘中硝氮、亚硝氮、氨氮和活性磷酸盐的平均含量均明显低于对照组(P < 0.05)。与对照组相比，浮床空心菜处理组对氨氮、硝氮和亚硝氮的平均清除率分别为30%以上、20%以上和19%以上。浮床空心菜处理组对活性磷酸盐(PO₄^3--P)的吸收清除率达40%以上，因此，浮床空心菜主要吸收磷酸盐和氨氮(NH₄⁺-N)，而对硝氮(NO₃-N)和亚硝氮(NO₂-N)的吸收较少。综合空心菜浮床对水质净化和青虾生长性能的改善指标，以TR2组为最优，在青虾养殖池塘中适度比例(13.5%)的种植空心菜生态浮床可以改善水质条件和提高青虾的生长性能和成活率。

Abstract: The effects of floating bed planting ratio of water spinach Ipomoea aquatica Forssk on water purification and growth performance of oriental river prawn Macrobrachium nipponense were studied in this paper. The tests were conducted in 8 earth ponds of same area which the density of oriental river prawn was 40 ind./m², three treatment groups were installed, the floating planting ratio of water spinach was 6.7% in treatment group 1 (TR1), the floating planting ratio of water spinach was 13.5% in treatment group 2 (TR2), and the floating planting ratio of water spinach was 27% in treatment group 3 (TR3), there was 2 earth ponds of no floating bed of water spinach as check group (CK). The results of three and half months (105 days) aquaculture test indicated that, the weight gain rate (WGR) and special growth rate (SGR) of oriental river prawn were increased by planting floating bed of water spinach. The survival rate (SR), yield and weight specifications of oriental river prawn in three treatment groups were significantly higher than in check group (P < 0.05); Feed Conversion Ratio (FCR) of oriental river prawn in three treatment groups were significantly lower than in check group (P < 0.05); but there was no significantly difference between three treatment groups for SR, Yield, weight specification and FCR of oriental river prawn (P > 0.05). Under the same environmental conditions and management methods, the results of the water quality analysis data showed that, the concentrations of ammonium, nitrate, nitrite and phosphate in all three treatment groups were significantly lower than in check group (P < 0.05). Compared to check group, the mean clearance rate (CR) of ammonium nitrogen, nitrate nitrogen and nitrite nitrogen in three treatment groups were respectively above 30%, 20% and 19%, the mean clearance rate (CR) of active phosphate in three treatment groups was above 40%, so floating bed of water spinach can strongly absorbed and removed to phosphate and ammonium nitrogen, but for nitrate nitrogen and nitrite nitrogen bed absorbed weakly by floating bed of water spinach. Integrated evaluated of water purification and oriental river prawn growth performance index, the TR2 were the best. So, approximately 13.5% of floating planting ratio of water spinach can improve water quality, and increase yield and SR of oriental river prawn, enhanced growth performance of Macrobrachium nipponense.