Mitigation of yield-scaled nitrous oxide emissions and global warming potential in an oilseed rape crop through N source management.

Enhanced-efficiency nitrogen (N) fertilizers, such as those containing nitrification or urease inhibitors, can mitigate the carbon (C) footprint linked to the production of bioenergy crops through a reduction in direct nitrous oxide (NO) emissions and indirect NO losses. These indirect emissions are derived from ammonia (NH) volatilization, which also have important environmental and health implications. The evaluation of the global warming potential (GWP) of different N sources using site-specific data of yield and direct and indirect emissions is needed for oilseed rape under rainfed semi-arid conditions, especially when meteorological variability is taken into account.

Global Research Alliance N O chamber methodology guidelines: Recommendations for deployment and accounting for sources of variability.

Adequately estimating soil nitrous oxide (N O) emissions using static chambers is challenging due to the high spatial variability and episodic nature of these fluxes. We discuss how to design experiments using static chambers to better account for this variability and reduce the uncertainty of N O emission estimates. This paper is part of a series, each discussing different facets of N O chamber methodology.

Nitrification inhibitor DMPSA mitigated N2O emission and promoted NO sink in rainfed wheat.

Fertilized cropping systems are important sources of nitrous oxide (NO) and nitric oxide (NO) to the atmosphere, and biotic and abiotic processes control the production and consumption of these gases in the soil. In fact, the inhibition of nitrification after application of urea or an ammonium-based fertilizer to agricultural soils has resulted in an efficient strategy to mitigate both NO and NO in aerated agricultural soils. Therefore, the NO and NO mitigation capacity of a novel nitrification inhibitor (NI), 2-(3,4-dimethyl-1H-pyrazol-1-yl) succinic acid isomeric mixture (DMPSA), has been studied in a winter wheat crop.

Determining the influence of environmental and edaphic factors on the fate of the nitrification inhibitors DCD and DMPP in soil.

Nitrification inhibitors (NIs) such as dicyandiamide (DCD) and 3,4-dimethylpyrazole phosphate (DMPP) provide an opportunity to reduce losses of reactive nitrogen (Nr) from agricultural ecosystems. To understand the fate and efficacy of these two inhibitors, laboratory-scale experiments were conducted with C-labelled DCD and DMPP to determine the relative rates of mineralization, recovery in soil extracts and sorption in two agricultural soils with contrasting pH and organic matter content. Concurrently, the net production of soil ammonium and nitrate in soil were determined.

The effect of nitrification inhibitors on NH and NO emissions in highly N fertilized irrigated Mediterranean cropping systems.

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.

"Hot spots" of N and C impact nitric oxide, nitrous oxide and nitrogen gas emissions from a UK grassland soil.

Agricultural soils are a major source of nitric- (NO) and nitrous oxide (NO), which are produced and consumed by biotic and abiotic soil processes. The dominant sources of NO and NO are microbial nitrification and denitrification, and emissions of NO and NO generally increase after fertiliser application. The present study investigated the impact of N-source distribution on emissions of NO and NO from soil and the significance of denitrification, rather than nitrification, as a source of NO emissions.

No tillage and liming reduce greenhouse gas emissions from poorly drained agricultural soils in Mediterranean regions.

No tillage (NT) has been associated to increased N2O emission from poorly drained agricultural soils. This is the case for soils with a low permeable Bt horizon, which generates a perched water layer after water addition (via rainfall or irrigation) over a long period of time. Moreover, these soils often have problems of acidity and require liming application to sustain crop productivity; changes in soil pH have large implications for the production and consumption of soil greenhouse gas (GHG) emissions.

N2O and CH4 emissions from a fallow-wheat rotation with low N input in conservation and conventional tillage under a Mediterranean agroecosystem.

Conservation agriculture that includes no tillage (NT) or minimum tillage (MT) and crop rotation is an effective practice to increase soil organic matter in Mediterranean semiarid agrosystems. But the impact of these agricultural practices on greenhouse gases (GHGs), such as nitrous oxide (N2O) and methane (CH4), is variable depending mainly on soil structure and short/long-term tillage. The main objective of this study was to assess the long-term effect of three tillage systems (NT, MT and conventional tillage (CT)) and land-covers (fallow/wheat) on the emissions of N2O and CH4 in a low N input agricultural system during one year.

Management of irrigation frequency and nitrogen fertilization to mitigate GHG and NO emissions from drip-fertigated crops.

Drip irrigation combined with split application of fertilizer nitrogen (N) dissolved in the irrigation water (i.e. drip fertigation) is commonly considered best management practice for water and nutrient efficiency.

Effectiveness of urease inhibition on the abatement of ammonia, nitrous oxide and nitric oxide emissions in a non-irrigated Mediterranean barley field.

Urea is considered the cheapest and most commonly used form of inorganic N fertilizer worldwide. However, its use is associated with emissions of ammonia (NH(3)), nitrous oxide (N(2)O) and nitric oxide (NO), which have both economic and environmental impact. Urease activity inhibitors have been proposed as a means to reduce NH(3) emissions, although limited information exists about their effect on N(2)O and NO emissions.