Influence of Urea Fertilizer Placement on Nitrous Oxide Production from a Silt Loam Soil

Abstract

Urea placement in band or nests has been shown to enhance N use efficiency, but limited work has been done to assess its affect on N(2)O emissions. This study compared N(2)O emissions from urea prills applied to an Amsterdam silt loam (fine-silty, mixed, superactive, frigid Typic Haplustolls) using broadcast, band, and nest placements. Experiments were conducted in greenhouse pots (200 kg N ha(-1)) and in canola (Brassica rapa L.) seeded fields using rates of 100 kg N ha(-1) (recommended) and 200 kg N ha(-1). Urea placement affected N(2)O emission patterns and cumulative N(2)O losses in the greenhouse and field. Urea prills placed in nests, and sometimes bands delayed N(2)O production with peak flux activity occurring later, and elevated emission activity being more prolonged than for broadcast applications. Differences were more obvious at 200 kg N ha(-1). These effects were attributed to a delay in urea hydrolysis and inhibition of nitrification. The fraction of applied urea-N lost as N(2)O for broadcast, band, and nest placements applied at the recommended rate averaged 2.0, 2.7, and 5.8 g N kg(-1) N, respectively. The fraction of applied urea-N lost as N(2)O averaged 2.9, 10.4, and 9.2 g N kg(-1) N for broadcast, band, and nest placements when urea-N rate was increased from 100 to 200 kg N ha(-1), respectively. Greater N(2)O production with nest placement may in part be due to significant soil NO(2)-N accumulations. Potential benefits to crop fertilizer use efficiency that come with placement of urea in concentrated zones may lead to enhanced N(2)O production.

Enhanced Efficiency Urea Sources and Placement Effects on Nitrous Oxide Emissions

“…Burton et al (2008a) also reported no impact of double midrow-banding to increase N 2 O emissions from fertilizers applied at the same rate (80 kg ha -1 ) as in the current study. In contrast, other studies (Engel et al, 2010;Maharjan and Venterea, 2013) used higher rates (180-200 kg ha -1 ) in studies simulating siderow-banding by hand trenching compared to those done in the northern Great Plains in Canada and found greater N 2 O emissions compared to broadcast incorporation. Beside the method of band placement, the differing effect of banding on emissions between studies could be due to a higher N rate per area increasing emissions within bands.…”

“…Surface side-banding of N fertilizers increased N 2 O emissions compared to surface-broadcast at an irrigated grain corn site in Central Great Plains of Colorado (Halvorson and Del Grosso, 2013). Hand-trenching using a hoe to simulated banding of urea delayed and increased N 2 O emissions compared to surface-broadcast under canola at a site in Montana (Engel et al, 2010). Single midrow-banding (banding between all rows) also by hand-trenching using a hoe, doubled N 2 O emissions compared to broadcast-incorporation of urea applied at 180 kg ha -1 to a corn site in Minnesota (Maharjan and Venterea, 2013).…”

Northwest U.S. Agriculture in a Changing Climate: Collaboratively Defined Research and Extension Priorities

“…Some existing experimental and modeling studies in eastern Washington State and southwest Montana have found N 2 O emissions, as a percentage of nitrogen applied, that are lower than the current Intergovernmental Panel on Climate Change (IPCC) benchmark of 1% (0.1-0.9%; Cochran et al, 1981;Dusenbury et al, 2008;Haile-Mariam et al, 2008;Engel et al, 2010). However, other inland Northwest studies suggest emissions are more in line with, or even notably above, the IPCC benchmark (1.1-4.4%; Halvorson, 2010;Stöckle et al, 2012;Waldo, 2016).…”

Bagan Warna Daun: Alat untuk Meningkatkan Efisiensi Pemupukan Nitrogen pada Tanaman Padi

“…Dari total pupuk urea yang diberikan kepada tanaman, hanya 50% yang dapat diserap oleh tanaman, sedangkan sisanya hilang karena tercuci maupun menguap ke udara (de Datta 1981). Emisi gas N 2 O dari lahan sawah meningkat dengan semakin tingginya takaran pupuk N (Engel et al 2010;Weller et al 2015). Pembentukan N 2 O dipicu oleh kondisi hara N yang berlebihan di dalam tanah pada kondisi tidak jenuh air (Sander et al 2014).…”