Copper is the element linked to protection from fungal disease. It is the "protein nutrient", increasing the uptake of ammonium form of nitrogen; it is essential for chlorophyll production, sugar synthesis and root metabolism, and it increases stalk strength and elasticity.
Although necessary for some microbes, copper can also have a fungicidal effect in the soil.
Copper is widely used and abused as a fungicide resulting in a toxic build-up in the soil, but Humic acid can help to buffer the microbe-killing effect. High copper also antagonises phosphorous, iron and zinc. Get copper into the leaf by way of building soil levels, rather than onto the leaf as a more sustainable disease control option. Cu sprays on the leaf cause a physiological change which may make the leaf more susceptible to disease agents.
Copper is critical for iron transportation in the blood and formation of hemoglobin, and is an anti-oxidant. It is also critical in the formation of the myelin sheath and is associated with elastin. It is a component of catalase and tyrosinase. Ruminants require 25-100 ppm in their feed; human optimum daily intake is 2-4 mg/day
Organ meats, shellfish, legumes and mushroom are rich in copper. Copper is an important coenzyme linked to immunity and detoxification. Symptoms of deficiency include severe diarrhoea, abnormal appetite, poor growth, and a course bleached coat. Split bark, lodging and brittle branches result from coper deficiency. High OM, molybdenum, iron or sulphur can induce copper deficiency, as can excess phosphate. Sources of copper include copper sulphate, licks, powder, blocks etc.
Copper sulphate can be added to troughs at 1gm/1000lt to control algae or 4gms/1000lt as a supplement. It can also be applied as a paste (2%) to control ring worm.
The minimum soil level is 2ppm; but get to 5-15ppm for better plant and animal stock health.