Physical Properties of Common Soils

Fertilizers are intentionally described in this chapter because each year huge tonnages are utilized in agriculture in order to enrich soils artificially for improving the growth of crops and without them soils could not sustain intensive food production. 

In practice, either industrial minerals or chemicals are currently used as feedstocks for manufacturing fertilizers and hence it is necessary to distinguish two groups  

Moreover, the above materials can be used individually as straight fertilizers but most of the time several feedstocks are mixed together to obtain a given grade for that reason they are called mixed fertilizers. Commercial mixed fertilizers are usually categorized into grades 

Hereafter, a brief description of major minerals and chemicals used in fertilizers is given, and for simplicity they are grouped according to the major chemical element they contain. 

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