Nitrogen is essential for raising crops and a deficiency will soon become evident. Older leaves on the plants start to turn yellow due to a reduction in chlorophyll production. Flowers, fruit, protein and starch content are all reduced when your crops suffer from nitrogen deficiencies.
Chlorosis Stunted growth General starvation
Maintaining sufficient fish populations is the best preventative measure to ensure adequate levels of nitrates, nitrites and overall nitrogen. Monitoring the nitrogen levels, as well as other nutrients, in your system will inform you regarding the types of crops that are compatible with your conditions.