Fertilizers are organic or mineral substances, often used in mixtures, intended to provide plants with additional nutrients, in order to improve their growth, and to increase the yield and quality of crops.
The different types of fertilizers are mineral, organic and organo-mineral fertilizers.
Mineral fertilizers are formed from substances of mineral origin (nitrogen (N), phosphorus (P) and potassium (K))
Organic fertilizers are of animal or plant origin (which can however be synthesized like urea)
Organo-mineral fertilizers Organo-mineral fertilizers are composed of mineral matter as well as a minimum of 25% of organic substances of animal or plant origin.

Urea (Specifications)
Total Nitrogen 46.00 % by weight minimum
Biuret 1.00 % by weight maximum
Moisture 0.40 % by weight maximum
Formaldehyde Range 0.45 % – 0.70 %
Size Distribution 97.5 % by weight minimum
Minimum Size 1.40 mm
Maximum Size 4.75 mm
Fines (0.5-1%) 1 % maximum