What is the chemical formula for the sulfate substance allowed in Organic farming?
Organic farming:  Synthetic substances that are allowed include, for example, copper sulfate, elemental sulfur and Ivermectin. Copper(II) sulfate: Copper(II) sulfate, also known as cupric sulfate, or copper sulphate, is the inorganic compound with the chemical formula CuSO(HO), where x can range from 0 to 5.
CuSO(HO)