Modern husbandry techniques, new crop varieties and highly effective methods of crop protection have enabled farmers and growers to increase yields (and quality) of their crops to levels unimaginable afew decades ago. This has put an ever increasing burden on the soil in terms of its ability to supply nutrients.

Farmers have responded to this by increasing the use of major nutrient fertilisers, but micronutrients have tended to be neglected. In addition, micronutrient inputs from traditional sources such as farm-yard manure and impure fertilisers have declined. As a direct result, micronutrient deficiencies are now widespread and increasing in severity.