Trace element fertilizers are mainly inorganic salts or oxides, some minerals, metallurgical by-products or wastes, can often be used as raw materials for trace element fertilizers, and their production methods are the same as those of inorganic chemical products.

　　Because the application amount per unit area is very small, so it must be diluted with a large number of inert substances before application, uneven application will poison some crops. Trace element fertilizers often need to be mixed into the regular fertilizers applied together, usually using two methods: one is in the production of regular granular fertilizers mixed in. This method is more convenient, economical, will not produce uneven nutrients, the disadvantage is less flexible, difficult to meet the market's various requirements; the other is the micronutrient fertilizer powder coated in the surface of the regular granular fertilizer. This operation can be carried out in the secondary processing plant, which can meet the needs of the market at any time.

　　There are two methods of micronutrient fertilizer application: soil application and foliar spraying.

　　Soil application: commonly used micronutrient fertilizers in addition to chemical fertilizers (such as borax, zinc sulfate, manganese sulfate, etc.), as well as glass fertilizers, slag or scraps, usually used as a base fertilizer or seed fertilizer. Its application method is: in the sowing before the combination of land application into the soil, or with nitrogen, phosphorus, potassium and other fertilizers mixed together, evenly applied, the application amount should be based on the crop and the type of micronutrient fertilizer, generally should not be too large.

　　Extra-root fertilizer: soluble micronutrient fertilizer is formulated into an aqueous solution of a certain concentration, and sprayed on the crop stems and leaves. The advantage of this method is to avoid harm caused by uneven fertilizer in the soil, but also in the different developmental stages of the crop, according to the specific needs of multiple spraying, in order to improve the effectiveness of fertilizer.