The effect of nitrification inhibitors on NH3 and N2O emissions in highly N fertilized irrigated Mediterranean cropping systems

Abstract

There is an increasing concern about the negative impacts associated to the release of reactive nitrogen (N) from highly fertilized agro-ecosystems. Ammonia (NH) and nitrous oxide (NO) are harmful N pollutants that may contribute both directly and indirectly to global warming. Surface applied manure, urea and ammonium (NH) based fertilizers are important anthropogenic sources of these emissions. Nitrification inhibitors (NIs) have been proposed as a useful technological approach to reduce NO emission although they can lead to large NH losses due to increasing NH pool in soils. In this context, a field experiment was carried out in a maize field with aiming to simultaneously quantify NH volatilization and NO emission, assessing the effect of two NIs 3,4‑dimethilpyrazol phosphate (DMPP) and 3,4‑dimethylpyrazole succinic acid (DMPSA). The first treatment was pig slurry (PS) before seeding (50 kg N ha) and calcium ammonium nitrate (CAN) at top-dressing (150 kg N ha), and the second was DMPP diluted in PS (PS + DMPP) (50 kg N ha) and CAN + DMPSA (150 kg N ha) also before seeding and at top-dressing, respectively. Ammonia emissions were quantified by a micrometeorological method during 20 days after fertilization and NO emissions were assessed using manual static chambers during all crop period. The treatment with NIs was effective in reducing c. 30% cumulative NO losses. However, considering only direct NO emissions after second fertilization event, a significant reduction was not observed using CAN+DMPSA, probably because high WFPS of soil, driven by irrigation, favored denitrification. Cumulative NH losses were not significantly affected by NIs. Indeed, NH volatilization accounted 14% and 10% of N applied in PS + DMPP and PS plots, respectively and c. 2% of total N applied in CAN+DMPSA and CAN plots. Since important NH losses still exist even although abating strategies are implemented, structural and political initiatives are needed to face this issue.

Successive straw biochar amendments reduce nitrous oxide emissions but do not improve the net ecosystem economic benefit in an alkaline sandy loam under a wheat–maize cropping system

“…N 2 O is often emitted after N fertilization and it becomes most rapid with above 60% WFPS (Skiba & Ball, ). After heavy rainfall and precipitation events, or under the impetus of irrigation, high WFPS soil is conducive to denitrification (Recio et al, ). The BC application decreases the soil BD and increases the soil aeration and has been shown to contribute to the suppression of N 2 O emissions (Case et al, ).…”

Long-term changes in greenhouse gas emissions from French agriculture and livestock (1852–2014): From traditional agriculture to conventional intensive systems

“…However, taking into account the annual scale of our study, pulses of N 2 O emissions cannot be represented as observed after fertiliser applications (Bouwman, 1996;Hénault et al, 1998;Laville et al, 2011;Plaza-Bonilla et al, 2014;Benoit et al, 2015a;Recio et al, 2018), rainy events (Zheng et al, 2000;Lu et al, 2006;Beare et al, 2009) and during freeze and thaw periods and rewetting in semi-arid regions (Vilain et al, 2010;Lu et al, 2015;Wertz et al, 2016;Sanchez-Martín et al, 2010). However, the N 2 O emissions data gathered here were selected Fig.…”

Feasibility of stabilised nitrogen fertilisers decreasing greenhouse gas emissions under optimal management in sprinkler irrigated conditions

“…NIs depress the activity of Nitrosomonas bacteria in the soil, delaying the first step of the nitrification, which is the oxidation of NH4 + to NO2 - (Zerulla et al, 2001a(Zerulla et al, , 2001b. NIs contribute to the reduction in N2O emissions (Cayuela et al, 2017;Recio et al, 2018;Sanz-Cobena et al, 2017) and nitrate leaching losses (Díez-López et al, 2008;Díez et al, 2010;Quemada et al, 2013) but can increase the risk for NH3 volatilisation (Ferguson et al, 1984).…”