Straw amendment with nitrate-N decreased N2O/(N2O+N2) ratio but increased soil N2O emission: A case study of direct soil-born N2 measurements

Effect of legume intercropping on N<sub>2</sub>O emissions and CH<sub>4</sub> uptake during maize production in the Great Rift Valley, Ethiopia

“…3 (Wu et al, 2018). Mulching and the incorporation of crop residues lead to increased N mineralization and respiratory O 2 consumption, thus potentially enhancing N 2 O emissions both from nitrification and denitrification (Drury et al, 1991) if soil moisture is sufficient to support microbial activity and restrict O 2 diffusion into the soil.…”

Straw amendments did not induce high N2O emissions in non‐frozen wintertime conditions: A study in northern Germany

“…The addition of both straw and N fertilizer increased the emission of N 2 O (Köbke et al., 2018; Wu et al., 2018). We observed small increases in N 2 O emissions in the fertilized soils.…”

“…The straw residues of wheat or oilseed rape crops are commonly left in fields after the autumn harvest in wheat‐barley‐oilseed rape rotation systems in Germany. Mineralization of the straw residues can increase the availability of both soil organic carbon (C) and nitrate (NO 3 − ) and, in turn, nitrous oxide (N 2 O) emissions (Senbayram, Chen, Budai, Bakken, & Dittert, 2012; Wu et al., 2018). N 2 O is a potent greenhouse gas with a warming potential 300 times higher than that of carbon dioxide (CO 2 ) (Intergovernmental Panel on Climate Change, 2013) and is also the most important chemical species in the depletion of atmospheric ozone (Ravishankara, Daniel, & Portmann, 2009).…”

“…Glucose was applied as a rapid organic C source (Blagodatskaya, Blagodatsky, Anderson, & Kuzyakov, 2007) compared to slowly decomposing oilseed rape straw. We also included different N fertilizer levels for the following reasons: (a) to create different C:N ratios with the additions, because this ratio is an important factor for denitrifying bacteria, and thus for soil N 2 O emission (Senbayram et al., 2012; Wu et al., 2018); (b) to investigate whether nitrate is a constraining factor on soil N 2 O emission in non‐frozen wintertime; and (c) to avoid N limitations on straw decomposition; it has been reported that mineral N availability is an important factor controlling plant residue decomposition under field conditions (Mary et al., 1996). Our hypotheses were as follows: (a) the addition of glucose would increase CO 2 and N 2 O emissions sharply and (b) the addition of straw would increase CO 2 and N 2 O emissions more slowly and continuously.…”

Regulation of the product stoichiometry of denitrification in intensively managed soils

“…Soil labile C content affects denitrification by supplying easily decomposable C to denitrifying micro‐organisms and lowering the oxygen level at microsites where decomposition occurs (Lan et al., 2015). It is well accepted that high nitrate concentrations in soil inhibit N 2 O reduction to N 2 (Blackmer & Bremner, 1978; Firestone et al., 1979; Qin et al., 2017; Senbayram et al., 2012; Wu, et al., 2018). Furthermore, Senbayram et al.…”