Decomposition of Urea Phosphate in Soils

Studies of the decomposition of urea phosphate (NH 2 CO‐NH 2 · H 3 PO 4 ) in soils showed that the phosphoric acid in this compound retards enzymatic hydrolysis of the urea by soil urease and reduces gaseous loss of urea N as ammonia. When soils treated with urea and urea phosphate were incubated at 20C for 14 days, the percentage loss of urea N as ammonia was 4.6–61.1% (average, 21.2%) for the soils treated with urea, but was only 0.1–1.1% (average, 0.7%) for the soils treated with urea phosphate. The studies reported support the conclusion from previous work that urea phosphate has significant potential advantages over urea as a fertilizer.