Prilled Urea 46% consists of 46% of nitrogen (N) in ureic form, simply absorbed with the leaves of plants. Absorption through the basis system is slower, because urea in soil is transformed (being a result of enzymatic hydrolysis) into the ammonia form available for plants, and then into nitrate form. https://nebula-directory.com/listings1149702/not-known-details-about-urea-fertilizer-subsidy