Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2006
Publication Date: 4/20/2007
Citation: Liu, G.D., Li, Y.C., Alva, A.K. 2007. High water regime can reduce ammonia volatilization from soils. Communications in Soil Science and Plant Analysis. 38: 1203-1220. Interpretive Summary: All forms of nitrogen (N) fertilizers applied to the soil eventually are transformed into ammonium and nitrate forms. The ammonium form may be lost in gaseous form as ammonia, depending on the soil and environmental factors. This form of N loss is referred to as 'ammonia volatilization'. Volatilization loss of N was examined in two soils from a major potato growing area in Washington and two soils from Florida, with application of 75 kg/ha N as either potassium nitrate, ammonium nitrate, ammonium sulfate, or urea at two soil water regimes (20% or 80% of field capacity) and at three incubation temperatures (11, 20, or 29 degrees C). This study revealed that ammonia volatilization loss was greater in dry soil conditions.
Technical Abstract: Ammonia volatilization is an important mechanism of nitrogen (N) loss from soils which is dependent on several soil and management factors. This research was conducted with Biscayne Marl Soil and Krome Gravelly Loam from Florida and Quincy Fine Sand and Warden Silt Loam from Washington to determine ammonia volatilization at various temperature and soil water regimes using either potassium nitrate (KNO3), ammonium nitrate (NH4NO3), ammonium sulfate ((NH4)2SO4), or urea applied to the soil at 75 kg/ha N rate. Soil water regime was maintained at either 20% or 80% of field capacity (FC), and incubated at either 11, 20, or 29º C which represent the minimum, average, and maximum temperatures, respectively, during potato growing season in Washington. Results indicated that the ammonia volatilization rate at 20% FC soil water regime was 2- to 3-fold greater than that at 80% FC. The cumulative volatilization loss over 28 days accounted for 0.21% loss of N applied as NH4NO3. This loss increased to 25.7% for (NH4)2SO4. Results of this study demonstrate that NH3 volatilization was accelerated at low soil water regimes. Thus, maintaining near optimum soil water regime is important to minimize volatilization loss of N and to improve N uptake efficiency in addition to its direct effects on plant growth and nutrient uptake.