利用光合菌微生物肥料降低水耕葉菜類中的硝酸鹽含量

近年來，蔬菜中殘留過量的硝酸鹽已成為消費者關切的食品安全議題，而含氮肥料的不當使用容易造成植體中的硝酸鹽含量超標。微生物肥料具有改善土壤理化性質，幫助植物吸收養分以及維持健康的特性，可以減少農化產品的施用，被視為一種對環境友善的施肥方式，可兼顧到農作豐產與自然生態平衡。先前從臺灣北部水田土壤所篩選到的一株Rhodopseudomonas palustrisNTUIOB-PS3光合菌，在土壤耕作系統上已被證明對於多種作物具有顯著的促進生長功效，還可有效提昇植物代謝利用化學肥料的效率。本研究的目的，旨在評估PS3光合菌潛力菌株在水耕系統上做為生物性肥料的可行性。所有試驗皆在完全人工光源型的植物工場內進行，藉由添加菌液至水耕養液中，檢驗該菌肥對於各種葉菜類，包括十字花科的丸葉山東小白菜與翠玉小白菜，以及菊科的皺葉萵苣，產量（鮮乾重）與植體內硝酸鹽含量的影響。根據試驗結果，在濃度減半的水耕養液中添加PS3菌肥，不僅使蔬菜的產量上升，而且植株對養液中的氮素利用效率明顯獲得提昇（與對照組相比增加了17-44%）。此外，該處理下的蔬菜硝酸鹽濃度顯著地減少，以丸葉山東小白菜為例，相較於未添加菌肥的全量濃度養液處理組，其硝酸鹽含量從約4,000 ppm降至500 ppm以下，下降幅度高達88%。因此，PS3光合菌潛力菌株可利用做為水耕栽培系統上的微生物肥料，達到增加作物產量與降低植體內硝酸鹽含量的功效。

關鍵字

硝酸鹽；水耕蔬菜；植物工場；促進植物生長根圈微生物；微生物肥料；光合菌

並列摘要

In recent years vegetable nitrate content is of concern to consumers because of the possible health risk. Excessive accumulation of nitrate in leafy crops is often associated with overuse of nitrogen fertilizers. Application of biofertilizer to farming is regarded as environmentally friendly approach and is reported to be able to improve soil property and health as well as to promote crop growth. A phototrophic bacterium, Rhodopseudo-monas palustris NTUIOB-PS3 strain (abbreviated as PS3), which isolated from local paddy soil, has been found to provide not only beneficial effects to plant growth but also enhanced uptake efficiency of applied fertilizer nutrients in soil cultivation system. The aim of this research was to evaluate the potential of PS3 inoculant as a biofertilizer in hydroponic system. Three leafy vegetables, including Maruba Santoh (Brassica rapa var. chinensis), Cuiyu (Brassica rapa var. chinensis) and crinkle garden lettuce (Lactuca sativa var. crispa), were grown in a plant factory, and the phototrophic bacterial inoculants were supplemented with the hydroponic nutrient solution during cultivation. By application of PS3 inoculant in half strength solution, nitrogen use efficiency (NUE) of these three vegetable species was significantly improved, and so as their yields. Furthermore, nitrate content in these vegetables was also reduced. Under the treatment, nitrate concentration of Maruba Santoh was less than 500 ppm, relative to more than 4,000 ppm in those cultivated in full strength hydroponic solution without inoculant. As nitrate content was decreased by 88%, it proved that PS3 strain is an elite inoculant to be used in hydroponic systems for a better yield with a less nitrate content.

並列關鍵字

Nitrate ； Hydroponic vegetable ； Plant factory ； Plant growth promoting rhizobacteria (PGPR) ； Biofertilizer ； Photosynthetic bacteria

國際替代計量

利用光合菌微生物肥料降低水耕葉菜類中的硝酸鹽含量

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