Requisitos de qualidade física e química de fertilizantes minerais

This paper deals with the characteristics of mineral fertilizers which affect the efficiency of these products as a source of nutrients for crops. It will be discussed here the physical fertilizer quality: particle size, granule hardness, flowability and density; chemical quality: number, concentration and chemical form of the nutrients and contaminants; physico-chemical quality: solubility, hygroscopicity, caking and salinity index. Those factors are related to practical problems as the height of pile of fertilizers bags during storage, chemical compatibility in mixtures and uniformity of fertilizer distribution during its application in the field.