Moisture Quotients for Ammonia Volatilization from Four Soils in Potato Production Regions

Abstract

Ammonia (NH 3 ) emission from nitrogen (N) fertilizers used in agriculture decreases N uptake by the crop and negatively impacts air quality. In order to better understand the factors influencing NH 3 emission from agriculture, this research was conducted with four major soils used for potato production: Biscayne Marl Soil (BMS, pH 7.27), and Krome Gravelly Loam (KGL, pH 7.69) from Florida; and Quincy Fine Sand (QFS, pH 6.65), and Warden Silt Loam (WSL, pH 6.46) from Washington. Potassium nitrate (KNO 3 ), ammonium nitrate (NH 4 NO 3 ), ammonium sulfate ((NH 4 ) 2 SO 4 ) or urea ((NH) 2 CO) sources were evaluated for ammonia volatilization at 75 kg N ha −1 rate. The soil water regime was maintained at either 20 or 80% of field capacity (FC), and incubated at 11, 20 or 29°C. Results indicated that NH 3 volatilization rate at 20% FC was 2 to 3-fold greater than that at 80% FC. The cumulative volatilization loss over 28 days ranged from 0.21% of N applied as NH 4 NO 3 to 25.7% as (NH 4 ) 2 SO 4 . Results of this study demonstrate that NH 3 volatilization was accelerated at the low soil water regime. Moisture quotient (Q) is defined as a ratio of NH 3 emission rate at 20% FC to that at 80% FC both at the same temperature. The peak Q values of NH 3 volatilization were up to 20.8 for the BMS soil at 20°C, 112.9 for the KGL soil at 29°C, 19.0 for the QFS soil at 20°C, and 74.1 for the WSL soil at 29°C, respectively. Thus, maintaining a suitable soil water regime is important to minimize N-loss via NH 3 volatilization and to improve N uptake efficiency and air quality.

Environmental Conditions in Beef Deep-Bedded Mono-Slope Facilities: A Descriptive Study

“…The results for all four soil types showed that the lower the soil moisture content, the higher the amount of NH 3 volatilization (Liu et al, 2007). Water acts a solvent to transport NH 4 + away from the soil surface (Liu et al, 2007). The drier bedded pack during the hot months may have contributed to higher concentration of NH 3 in the air samples from the pen surface of BDMF.…”

“…Jeppsson (1999) reported an increase in NH 3 emissions in deep-bedded dairy barns when the temperature of the bedded pack increased from 21.4°C to 30.0°C. Elevating the temperature of the soil has been shown to increase NH 3 losses from the surface of open feedlots (Sherwood et al, 2006) and from soils receiving urea fertilizer (Liu et al, 2007). Higher temperatures also increased NH 3 losses from waste treatment lagoons (Aneja et al, 2001) and poultry litter (Liu et al, 2006).…”

“…In dry soil, the transport of NH 4 + ions from the soil surface down to the deep soil horizon is restricted; hence, increased losses of nitrogen occur as NH 3 emissions from the soil (Liu et al, 2007). Sherwood et al (2007) reported an increase in NH 3 losses from the surface of open feedlots when the moisture content of the soil was decreased.…”

“…Sherwood et al (2007) reported an increase in NH 3 losses from the surface of open feedlots when the moisture content of the soil was decreased. Liu et al (2007) measured NH 3 volatilization following application of N fertilizer on four different soil types. The results for all four soil types showed that the lower the soil moisture content, the higher the amount of NH 3 volatilization (Liu et al, 2007).…”

“…Liu et al (2007) measured NH 3 volatilization following application of N fertilizer on four different soil types. The results for all four soil types showed that the lower the soil moisture content, the higher the amount of NH 3 volatilization (Liu et al, 2007). Water acts a solvent to transport NH 4 + away from the soil surface (Liu et al, 2007).…”