Nutrient pollution

thumb|313x313px|Eutrophication can cause harmful algal blooms like this one in a river near Chengdu, China.

thumb|The Passaic Agricultural Chemical Works in Newark, New Jersey, 1876 An agrochemical or agrichemical, a contraction of agricultural chemical, is a chemical product used in conventional or industrial agriculture. Agrochemical typically refers to pesticides and synthetic fertilizers. The term agrochemical is sometimes used informally synonymously with pesticides, sometimes also informally to mean pesticides and fertilizers, and sometimes more correctly to include all chemicals used in agriculture. Other chemicals used in agriculture are plant hormones and plant growth regulators (PGRs), ins

contamination of water by excessive inputs of nutrients