Nitrogen fertilizers supply nitrogen in one of three chemical forms: amide (urea), ammonium (NH₄⁺) or nitrate (NO₃⁻). Plants take up ammonium and nitrate directly; amide nitrogen must first hydrolyse to ammonium. Ammonium is held on soil exchange sites and resists leaching until soil bacteria oxidise it to nitrate, a process that releases hydrogen ions and acidifies the root zone. Nitrate moves freely with soil water and is prone to leaching and, in waterlogged soil, to denitrification. Form therefore governs timing, placement and loss pathway.
Nitrogen fertilizer grades
This category covers 26 product pages built on 3 substances. Grades differ by physical form, purity tier and production route; the chemical identity is stated on every page by CAS number.