Loss of Nitrogen from Ammoniacal Fertilizers Incubated under Different Soil and Termperature Conditions.

Abstract

Ammonium sulfate and urea were added to three soils of widely different composition. After incubation for 28 days at 20o C, from 13 to 89% of the N from ammonium sulfate, and 8 to 71% of the N as urea were not recovered, and at 40oC, 44 to 95% of the N as ammonium sulfate, and 33 to 81% of the N as urea was not recovered as either ammonium-N or nitrate-N. Significantly more N was lost from a soil containing 3% calcium carbonate at pH 8.4 as compared to the two other soils containing 25 and 35% calcium carbonate, which have pH's of 7.7 and 7.5, respectively. An incubation temperature of 40oC appeared quite unfavourable for nitrification.