吳郭魚與珠蔥之淡水魚菜共生系統研究

Abstract

魚菜共生自1970年代以來為農糧與養殖業帶來了新的概念，魚菜共生結合了養殖與水耕，將養殖廢汙中的氨氮透過硝化作用變成植物能利用的氮營養鹽，而被植物淨化後的水可以再繼續循環利用，魚菜共生能夠節省大量水資源，是結合永續發展概念的新型態農業。 然而，魚菜共生系統中魚與菜比例需透過生物排放與植物吸收實驗，進行氮營養鹽的收支計算，為魚菜共生系統主要的平衡關鍵。本研究以吳郭魚與珠蔥為實驗對象，建立魚菜比例的數據，計測總重224g的魚體之單日排泄累積實驗。再利用魚池底泥製成液肥試驗，浸泡出固定濃度的澆灌液肥廢汙，利用澆灌液肥或去離子水的方式製造5種濃度模組，作植物澆灌試驗，進行21日種植。利用種植前後之土壤分析實驗計測植物消耗之氮營養鹽，並將結果與吳郭魚單日排泄累積實驗進行計算，推估出吳郭魚與珠蔥之魚菜比例。 結果得知，利用廢汙澆灌0.329 mg的氮營養鹽，可使珠蔥有最佳生長速率，每增加1%的廢汙澆灌營養鹽可增加4.95%的植物生長。進行魚菜比例估算，可得知45±5.7g體型吳郭魚每1kg魚體所排泄之氮營養鹽，每日能夠提供93.24g的珠蔥吸收。本研究建立明確的生物排泄與植物吸收之實驗架構，提供魚菜比例計算方法，為國內魚菜共生系統配比研究之首篇，期待能對環境平衡管理型生物系統環境設計有實質助益。

Aquaponics have brought about a new concept for food production since 1970. Aquaponics combined aquaculture and hydroponics, utilizing purified wastewater by nitrification from aquaculture, and use the water for plants. This simplified process can reduce water wasting, and creates a new way of sustainable development for agriculture. However, the nutrients balance between the ecretion from aquatic and the abosorb from the absorption of plants which is the key to the success of running the system need to be determined by experiments. Tilapia and Shallot are the experimental subjects in this study. The total weight of 224g of Tilapia were used for the fish daily ecretion experiment. In order to irrigate the plants with the fixed concentration water, this study conducted the pond sediment soaked experiment to make simlar wastewater. There are five different irrigation types were set up into five different concentration groups by irrigating regularly with deionize or wastewater, represented by 0A,1A,2A,3A and 4A, respectively. After 21 days of irrigation experiment, the soil experiments were conducted before planting and after harvest, determining the nitrogen nutrients absorbed by Shallots. With the nitrogen nutrients data of ecretion and absorption, the ratio between the Tilapia and Shallot could be calculated. With the experimental design of this study, the results shows that irragating Shallots by wastewater with 0.329mg of nitrogen nutrients increased 4.95% of plants growth with adding 1% nitrogen nutrients. The calculation results of fish and plants show that per kg of Tilapia (with size of 45±5.7g) could provide nitrogen nutrients for daily use by Shallot of 93.24g. This study created a new experimental architecture to find out the ratio between the fish and plants, and the results of nitrogen nutrients between fish(Tilapia) excretion and plants(Shallot) uptake could be used in Aquaponics system and help to stabilize the system. This study is the first domestic research of determining the nitrogen nutrients balance for aquaponics system.