Fate of urea nitrogen in soils

Adequate fertilization is a prerequisite for modern agriculture to achieve high yields in quality and quantity. Among the key elements of this, nitrogen is frequently mentioned. It is often found in the soil in insufficient quantities to allow for optimal crop growth. Even when it has been applied to the soil, because of its dissipation in various forms: leaching and volatilization in particular, it is always a problem.Hence the objective of this study to evaluate, in the laboratory, the mineralization kinetics of urea used in a Arenoferralsol and a Ferralsol by evaluating the ammonia loss and nitrification rates. At the same time, the amount of CO2 (soil respiration) was also monitored under controlled conditions for 15 days. Ammonia and nitric nitrogen in the soil were measured periodically (days 0, 3, 7, 11 and 15). By trapping, NH3 was retained in H2SO4 and CO2 in caustic soda.