Urea has surpassed and nearly replaced ammonium nitrate as a fertilizer. It is a white crystalline solid containing 46% nitrogen, is widely used in the agricultural industry as an animal feed additive and fertilizer. Urea (46-0-0) usually has the lowest cost per pound of nitrogen compared to other single-element nitrogen fertilizers. Commercially, fertilizer urea can be purchased as prills or as a granulated material. In the past, it was usually produced by dropping liquid urea from a "prilling tower" while drying the product.
Advantages of Fertilizer Urea are:-
it can be applied to soil as a solid or solution or to certain crops as a foliar spray. Urea usage involves little or no fire or explosion hazard. It has high analysis, 46% N, helps reduce handling, storage and transportation costs over other dry N forms. when properly applied, results in crop yield increases equal to other forms of nitrogen.
After application to the soil, urea undergoes chemical changes and ammonium (NH4 +) ions form. Soil moisture determines how rapidly this conversion takes place.
When a urea particle dissolves, the area around it becomes a zone of high pH and ammonia concentration. This zone can be quite toxic for a few hours. Seed and seedling roots within this zone can be killed by the free ammonia that has formed. Fortunately, this toxic zone becomes neutralized in most soils as the ammonia converts to ammonium. Usually it’s just a few days before plants can effectively use the nitrogen. With small grains, 10 lb. of nitrogen as urea can generally be applied with the grain drill at seeding time even under dry conditions.
SPECIFICATIONS FOR UREA 46% Nitrogen grade:-
Nitrogen: 46 wt% Min.
Moisture: 0.5 wt% Max. By method of drying.
Free Ammonia: 160 ppm max.
Biuret: 1.0 wt% Max.
Color: Pure white free flowing without harmful substances.
Free Flowing: 100% anticaking treated.
Anti caking agent: 0.05% by weight.
Melting point: 132 degrees Celsius.
Granulation: 2-4 mm min. 90%.