Sulfur is intimately linked to nitrogen in that both minerals are protein building blocks. Two of the essential amino acids, cysteine and methionine, are sulfur-dependent. These are important nutrients in both animal and human nutrition as they are critical for detoxification (boosting protection in an increasingly toxic world).
Sulfur is also required for the conversion of nitrate nitrogen into protein within the plant leaf. The plant requires sulfur and molybdenum to produce the nitrate reductase enzyme. In the absence of this enzyme, nitrates accumulate within the plant, calling in insects (to perform their garbage collecting role) and reducing the oxygen carrying capacity of the blood of those animals and humans unfortunate enough to consume this toxic food. Multiple studies have linked nitrates to cancer over the past two decades. Nobel prize winner, Dr Otto Warburg, identified anaerobism as the root cause of cancer, and nitrates are a key cause of anaerobism. A small investment in sulfur can reduce the need for chemical intervention because excess nitrates are the single most potent driver of pest pressure.
Sulfur also aids in the translocation of sugars and starches down to the roots. This is why it is considered such a critical nutrient in root crops. Gypsum is often side dressed in crops like peanuts and potatoes to stimulate this translocation. If brix levels do not rise during the day it can be due to a sulfur deficiency. Excess nitrates, with their inevitable nutrient dilution factor, may be accumulating in the leaf due to a lack of sulfur. The other likely cause of brix levels remaining static throughout the day is a boron deficiency, as this mineral opens the trapdoor, which allows the nightly movement of sugars from the chloroplasts in the leaf down to the roots. Sulfur is also required for the formation of chlorophyll itself.
in flower, it is essential for the production of oils, terpenes, and amino acids necessary for calyx growth