Nitrous oxide emissions from denitrification and the partitioning of gaseous losses as affected by nitrate and carbon addition and soil aeration

Abstract

. 2008. Nitrous oxide emissions from denitrification and the partitioning of gaseous losses as affected by nitrate and carbon addition and soil aeration. Can. J. Soil Sci. 88: 133Á143. National inventories of N 2 O emissions from agricultural situations are being developed; however, the factors controlling such emissions may vary with soil and environmental conditions and management practices. This study determined the relative importance of soil aeration, as measured by water-filled pore space (WFPS), NO , N 2 O emissions and denitrification were low and were increased by both NO ( 3 and C addition treatments. Carbon source was investigated by amendment with glucose, red clover or barley straw. Based on the quantity of soil respiration per unit of C added in the amendment, C in the red clover and barley straw was estimated to be 48 and 28% as available as glucose C. When corrected for C availability, cumulative N 2 O emissions averaged 0.010, 0.011 and 0.002 mg N kg(1 soil, and cumulative denitrification averaged 0.014, 0.014 and 0.003 mg N kg (1 soil, for each 1.0 mg C kg (1 soil of available C added as glucose, red clover or barley straw, respectively. NO ( 3 addition had no effect on denitrification, but increased N 2 O emissions, especially where C availability was high. The amount of denitrification was controlled primarily by soil O 2 supply, as controlled by WFPS and C availability. The N 2 O:(N 2 O'N 2 ) ratio was generally high in cases where the supply of O 2 or NO 3 Á was sufficient to meet the demand for terminal electron acceptors. For personal use only.

Non‐Legume Cover Crops Can Increase Non‐Growing Season Nitrous Oxide Emissions

“…This is consistent with other studies that found NO 3 levels greater than 5 to 10 mg N kg -1 did not limit N 2 O production (Ryden, 1983;Gillam et al, 2008). It appeared over-winter soil conditions favored the use of NO 3 by facultative anaerobes as a terminal electron acceptor.…”

“…5a) [2013][2014]. This is consistent with other studies that have shown that N 2 O production was limited by NO 3 in low NO 3 soils and mineralizable C in high NO 3 soils (Weier et al, 1993;Gillam et al, 2008;Mitchell et al, 2013).…”

“…Thus, the risk of N 2 O emissions may be mitigated when soil NO 3 concentrations are low (Lemke et al, 1998;Wagner-Riddle and Thurtell, 1998;Burton et al, 2008;Chantigny et al, 2010). Other studies have reported that low available C appeared to limit N 2 O emissions (Lemke et al, 1998;Rochette et al, 2004;Gillam et al, 2008;Chantigny et al, 2010;Pelster et al, 2012), but this depends on soil characteristics, climate and cropping system (Rochette et al, 2004), with no clear distinction between C and NO 3 limitation. Overall, the NO 3 concentration at any given time may not be strongly correlated to the instantaneous N 2 O flux, but over the course of a growing season, or non-growing seasons in our case, the mean NO 3 level or intensity was an important control on the potential magnitude of N 2 O fluxes Chantigny et al, 2010).…”

Effect of fertilizer nitrogen management on N2O emissions in commercial corn fields

“…This is consistent with denitrification being the primary source of N 2 O emissions. Similarly, other field and laboratory studies within this region provided evidence that N 2 O emissions from agricultural soils are associated primarily with denitrification Gillam et al 2008;Zebarth et al 2008). for the denitrification process becomes limiting .…”

Effect of split application of fertilizer nitrogen on N2O emissions from potatoes

“…Soil NO 3 ( availability, aeration, and carbon availability are commonly identified as important factors controlling N 2 O emissions and denitrification (Knowles 1982;Weier et al 1993;Granli and Bøckman 1994;Gillam et al 2008). Soil water content is a major determinant of soil aeration through its effect in displacing the air-filled pore space.…”