Acta Agriculturae Zhejiangensis ›› 2023, Vol. 35 ›› Issue (7): 1709-1719.DOI: 10.3969/j.issn.1004-1524.20221119

• Environmental Science • Previous Articles     Next Articles

Effects of aquatic animals-plants synergistic purification system on water quality and economic benefit in mandarin fish pond

YANG Kun1(), HOU Guanjun1,*(), ZHAO Xiuxia1, FANG Ting1, WANG Lijun2   

  1. 1. Key Laboratory of Freshwater Aquaculture and Enhancement of Anhui Province, Fisheries Research Institute, Anhui Academy of Agricultural Sciences, Hefei 230031, China
    2. Chuzhou Longcai Fisheries Co., Ltd., Chuzhou 239060, Anhui, China
  • Received:2022-08-02 Online:2023-07-25 Published:2023-08-17
  • Contact: HOU Guanjun

Abstract:

In order to clarify the effects of the synergistic purification system of aquatic animals-plants (Ipomoea aquatica+Oryza sativa+Cristaria plicata) on water quality and economic benefits of mandarin fish (Siniperca chuatsi) culture ponds, one control group (0-F, without purification system) and two purification groups with a plant coverage rate of 10% (10%-F, 5% coverage for each of water spinach and rice) and 30% (30%-F, 15% for each of water spinach and rice) were set up. Crested mussels were also hunging cultured (50 ind per 667m2) in the ponds in the latter two groups. The water quality and growth rate of mussels were regularly monitored during the experiment, and the survival rate, yield and harvest of aquatic plants were determined at the end of the experiment. The results showed that there was no significant difference in water temperature and pH value among different groups. The water transparency of the purification groups was always higher than that of the control group. Compared with the initial mass concentration, the final mass concentration of total nitrogen (TN) in the 0-F group increased by 35.5%, and that of the 10%-F group and 30%-F group decreased by 23.8% and 49.0%, respectively. The final mass concentration of NH+4-N in 0-F group, 10%-F group and 30%-F group increased by 167%, 53% and 34% of the initial mass concentration, respectively. The final mass concentration of CODMn in 0-F group, 10%-F group and 30%-F group increased by 138.5%, 100.0% and 88.9% compared with the initial mass concentration, respectively. The total phosphorus (TP) mass concentration in each group showed a fluctuating downward trend with time. At the end of the experiment, the water quality, mandarin fish survival rate, yield and economic benefit were the best in the 30%-F group, followed by the 10%-F group, and the 0-F group was the worst. The per unit area yields of water spinach and rice in the 10%-F group were higher than those in the 30%-F group. The wet weight growth rate of mussels in 30%-F group was higher than that of 10%-F group. In general, the synergistic purification system can significantly improve the water quality and economic benefits of mandarin fish ponds, and the application effect of the purification system with 30% plant coverage was slightly better than that of purification system with 10% plant coverage.

Key words: synergistic purification, coverage rate, Ipomoea aquatica, Oryza sativa, Cristaria plicata, water quality

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