What points should one keep in mind while using fertilizers?

Fertilizers play an important role in the growth of the crops. Following points are kept in mind while using the fertilizers:

• The need of the crop tells the kind of fertilizer to be applied for e.g. cereals require more nitrogen and therefore the fertilizer containing more nitrogen should be used for the same.
• Fertilizers should be thoroughly tested so that any deficiency of the nutrient, if exist can be checked.
• Care should be taken about the right time and the place and the right amount while applying the fertilizer.