Ammonia Volatilization Reduction Induced by Bentonite Application to Sandy and Calcareous Soils

Ibrahim, M.S. 1; A. Abd El-Galil1; M.A. El-Desoky2; O.E. Negim1 and

Fatma N. Th1

A laboratory incubation experiment was carried out to study the effect of bentonite application on ammonia volatilization from applied urea fertilizer to sandy and calcareous soils using a closed dynamic air flow system. Four bentonite levels of 0, 1.25, 2.5 and 5% and two urea levels of 250 and 500 kg urea fed-1 wt/wt. All treatments were arranged in a completely randomized design with three replications. The soils treated with these treatments were moistened to field capacity and incubated for 29 days. The volatilized NH3 was collected from the soil chambers every 24 hours. The results revealed that amending the soil with bentonite reduced the average percentage of ammonia loss from 26.07 and 67.09% in control to 8.27 and 24.61% for the high level of bentonite application to the sandy and calcareous soils, respectively. Bentonite may be recommended as an amendment in sandy and calcareous soils.