Effects of different amounts of Zinc and Iron in nutrient solution on yield and leaves chemical composition of Spinach (Spinacia oleracea L. cv. Viroflay). Can anyone guide us about this issue?
Have tried googling anything? such as http://www.greenhouse.cornell.edu/crops/factsheets/hydroponic-recipes.pdf
or scholar.google.com?http://www.koreascience.or.kr/article/JAKO201912261947387.page
I found these in less than 30 seconds. I imagine it will depend to some extent on your varieties of spinach and the hydroponic setup how much iron and zinc you can adjust to alter for optimal nutrient composition.