Urea (Granular and Prilled): Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use. It is widely used in fertilizers and is an important raw material for the chemical industry.
Ammonium sulphate is an inorganic salt that is commonly used as a soil fertilizer. It contains 21% nitrogen and 24% sulphur.
Although Ammonia occurs naturally but it’s synthetically produced from the nitrogenous animal and vegetable matter. It is used as a fertilizer and helps in increasing yield when applied directly to the soil.