Together eight companies process 120 million pounds of industrial byproducts into fertilizer, roughly half of the total zinc fertilizer sold in the country (157).
Much of this has to do with the effect of agrichemicals, like insecticides, herbicides and large quantities of synthetic fertilizers, on what are considered beneficials.
With human activities, land run-off also now includes the many chemicals used as fertilizers in agriculture as well as waste from livestock and humans.
