Fertilizers

Substances to promote the growth, to increase the yields, or to improve the quality of crops. A distinction is made between manures (e.g. farmyard manure, liquid manure, guano, compost, straw and vegetable residues), mineral fertilizers (such as Phosphates, which are extracted from deposits by mining), and synthetic fertilizers (synthetically manufactured fertilizers such as nitrogen fertilizers and potassium fertilizers, etc.) in order that fertilizers do not introduce any additional Harmful Substances into the soil or into plants (e.g. Heavy Metals such as Lead, Cadmium or Mercury).