Zinc is the "energy micro-nutrient" required for correct functioning of many enzyme systems, being an important enzyme activator, second only to magnesium in terms of the number of enzymes to which it is linked. It is essential for phosphorous uptake, and is needed for ADP and ATP production. It regulates plant sugar and transforms carbohydrates. Zn is critical for uptake of moisture through roots. Zinc is required for synthesis of nucleic acids and is critical for soil organisms. Crops sensitive to Zn deficiency are; maize, linseed, green beans, fruit crops, pastures and cereals, (being involved in filling grain properly).
Zinc governs the production of auxins which determine leaf size, starch formation and may give the largest response of any trace element. Zinc must be properly matched with phosphorus in the soil. If phosphorus is high, zinc needs to be high. If phosphorus is low, zinc needs to be low. If they are out of kilter, the high one can block the low one.
Zinc antagonises iron, copper and sulphur so these should be “background nutrition” if they are marginal when applying zinc. Copper fungicides can induce a zinc deficiency. Zinc is essential to cell growth, replication, sexual maturity and reproduction. It works alongside vitamin A. It is essential to the immune system, natural killer cells and the thymus gland. It improves disease resistance, reproduction and reduces skin and feet disorders.
Zinc deficiency is directly linked to prostate cancer and breast cancer (our two largest cancers)
Ideal human intake is 15-20 mg/day. Cattle rations need to have 50-100 ppm.
Beef, shellfish, cheese and dark chocolate, leafy greens are rich in zinc; it is needed for the healing of wounds and for robust rumen organisms. Symptoms of zinc deficiency include decreased weight gains, lowered feed efficiency and poor wound healing. Required at 6-19.5ppm in the soil depending on phosphorus levels.
Diseases, pests and insect problems can easily be avoided by having a balanced soil. You cannot treat each nutrient in isolation; it is not that simple. Every nutrient, major or minor must be in balance. To achieve that, adding minute quantities may keep symptoms away, but not remove the potential cause of a particular problem. It takes approximately 2kg of a particular element to raise soil levels by about 1ppm. Soil applied nutrients delivered through forage, supply the correct bio-available forms to the animals that eat them. Supplemental feeding, in many cases is merely treating symptoms, not addressing the causes. E.g. feeding animals manganese may not prevent brucellosis, but applying it to the soil may. Once the soil is adequately supplied with all relevant minerals, they take a long time to deplete.