In acidic or neutral soils, it tends to remain relatively insoluble and the amount of biologically available selenium should steadily decrease. Silver nitrate, the most important silver compound, is used extensively in photography. Silver iodide is used in seeding clouds to produce rain. While silver itself is not considered to be toxic, most of its salts are poisonous due to the anions present. Silver compounds can be absorbed in the circulatory system and reduced silver deposited in the various tissues of the body.
Rainfall removes zinc from soil because the zinc compounds are highly soluble.
These hydrolyzed species strongly adsorb to soil surfaces. Zinc forms complexes with inorganic and organic ligands, which will affect its adsorption reactions with the soil surface.