In summary, this study provided evidence that Fe-supply levels
significantly affect biomass production and quality of spinach in
hydroponic cultivation. In soilless agricultural production, we recommend
supplying low Fe (e.g. 1 lM FeEDTA) to the spinach, so as
to obtain a mild Fe-deficient status in plants. This will not only increase
the biomass production, it will also improve the quality by
decreasing nitrate accumulation and increasing soluble sugar and
protein contents. Furthermore, a lower Fe supply could also increase
the ascorbate content in spinach while allowing it to retain
its antioxidant-related qualities.