Nitrous Oxide Emissions with Enhanced Efficiency Nitrogen Fertilizers in a Rainfed System

Abstract

The use of enhanced efficiency N fertilizers can increase crop N utilization and lead to lower emissions of the greenhouse gas N 2 O. To determine the potential benefit of four enhanced efficiency fertilizers with rainfed corn (Zea mays L.) production in central Pennsylvania, N 2 O emissions and grain yield were monitored during a 4-yr field study and compared with untreated urea prills and urea-NH 4 NO 3 (UAN). The tested enhanced efficiency products were ESN (polymer-coated urea), SuperU (urease and nitrification inhibitor treated urea), UAN treated with AgrotainPlus (urease and nitrification inhibitors), and PiNT (cationstabilized amine-N). Additionally, 28-d laboratory incubations were conducted to verify the potential differences in N cycling rates among N sources. The laboratory incubations indicated that ESN, SuperU, and treated UAN all had the potential to delay accumulation of NO 3 relative to untreated urea and UAN, but N cycling was similar with PiNT and the untreated fertilizers. Extended dry periods limited the denitrification potential and overall N 2 O emissions in the field, but spikes of N 2 O emission were seen within 1 mo after fertilizer application in each year. However, variation in emission rates was high within treatments, and no consistent differences among N sources were seen. Cumulative growing season N 2 O emissions and grain yield were similar for all N sources in each year of the study. Enhanced efficiency fertilizers do not appear to be an effective means to reduce N 2 O emission in a rainfed system, at least when rainfall is inconsistent.

Impacts of Enhanced‐Efficiency Nitrogen Fertilizers on Greenhouse Gas Emissions in a Coastal Plain Soil under Cotton

“…Few other patterns were observed except that the control tended to have the lowest N 2 O flux throughout most of the study, which is logical given that no N was applied. While some researchers have reported reductions in daily N 2 O flux with use of nitrification inhibitors (Mosier et al, 1998; Jumadi et al, 2008) or EENFs (Halvorson et al, 2010a,b; Halvorson et al, 2011; Halvorson and Del Grosso, 2012; Asgedom et al, 2014), others have reported few differences between commercial fertilizers and EENFs (Parkin and Hatfield, 2014; Dell et al, 2014) as seen in the current study. Sistani et al (2011) found that ESN had lower daily N 2 O emissions early in the growing season but higher emissions after a 3 to 4 wk delay compared with other fertilizers.…”

“…Soil N 2 O production primarily occurs through nitrification and denitrification processes (Firestone and Davidson, 1989). Nitrification has been identified as the primary source of N 2 O in many aerobic soils, and denitrification being the primary source under anaerobic conditions (Bremner, 1997; Dell et al, 2014). Denitrification has been reported to occur in anaerobic microsites within partially aerated soils, which also contributes to the N 2 O loss budget (Parkin, 1987).…”

Agro‐Environmental Consequences of Shifting from Nitrogen‐ to Phosphorus‐Based Manure Management of Corn

“…Vented chambers were constructed following a design presented in Dell et al (2014). Stainless steel cafeteria serving pans (Vollrath Corporation, Sheboygan, WI) were used with a port fitted on top for sampling with a needle and syringe.…”

“…Most research suggests greater N 2 O emissions will occur with a higher N rate (Lessard et al, 1996;Jarecki et al, 2009;Dell et al, 2014;Halvorson et al, 2014). For example, Lessard et al (1996) reported a 0.47 kg ha -1 increase in N 2 O emissions when dairy manure rates increased from 170 to 339 kg N ha -1 .…”

Enhanced Efficiency Fertilizers: A Multi‐Site Comparison of the Effects on Nitrous Oxide Emissions and Agronomic Performance

“…In cotton production in the southeast, there was no effect of EEF materials on yield or fiber quality (Watts et al, 2014). The majority of the studies evaluated the effect of EEF materials on corn yield and showed inconsistent effects on grain yield (Dell et al, 2014;Halvorson and Bartolo, 2014). The use of EEF materials caused an increased greenness in corn canopies in Iowa and increased grain yield because of the delayed senescence of the plant canopy .…”