On alkaline and close-to-neutral soils, urea must be embedded in the soil no later than 2 to 6 hours after application or applied directly to a depth of 4-6 inches. This will help reduce nitrogen losses in the form of ammonia as a result of hydrolysis and activity of urease soil enzymes. The use of urea as a pre-seed fertilizer is possible only if the distance from the seeds is at least 2 inches in order to avoid damage to seedlings and root hairs with a high concentration of NH₃ in the urea appearing during hydrolysis.