Preconditions for Including the Effects of Urease and Nitrification Inhibitors in Emission Inventories.

Urease and nitrification inhibitors can reduce ammonia and greenhouse gas emissions from fertilizers and manure but their effectiveness depends on the conditions under which they are used. Consequently, it is essential for the credibility of emission reductions reported in regulatory emission inventories that their effectiveness is assessed under real-world conditions and not just in the laboratory. Here, we specify the criteria we consider necessary before the effects of inhibitors are included in regulatory emission inventories.

Mitigation of ammonia and methane emissions with manure amendments during storage of cattle slurry.

This study aimed at assessing the efficacy of manure amendments in abating ammonia (NH) and methane (CH) emissions during storage. Two experiments were carried out. Experiment 1 was conducted using 20 L of slurry for 98 days.

Revisiting sampling duration to estimate NO emission factors for manure application and cattle excreta deposition for the UK and Ireland.

According to the available guidelines, good practices for calculating nitrous oxide (NO) emission factors (EFs) for livestock excreta and manure application include that sampling duration should be of at least one year after the nitrogen (N) application or deposition. However, the available experimental data suggest that in many cases most emissions are concentrated in the first months following N application. Therefore resources could be better deployed by measuring more intensively during a shorter period.

Low NO emissions associated with sheep excreta deposition in temperate managed lowland grassland and extensively grazed hill pasture.

Nitrous oxide (NO) is a potent greenhouse gas (GHG) whose emission from soil can be enhanced by ruminant excretal returns in grasslands. The default (Tier 1) emission factors (EF; i.e.

Effect of contrasting phosphorus levels on nitrous oxide and carbon dioxide emissions from temperate grassland soils.

Agricultural practices such as repeated fertilization impact carbon (C), nitrogen (N) and phosphorus (P) cycling and their relationships in the plant-soil continuum, which could have important implications for the magnitude of greenhouse gas emissions. However, little is known about the effect of C and N additions under contrasting soil P availability status on nitrous oxide (NO) and carbon dioxide (CO) emissions. In this study, we conducted a field-based experiment that investigated the impact of long-term (23 years) P management (no (P0, 0 kg P ha), low (P15, 15 kg P ha) and high (P45, 45 kg P ha) P inputs) on NO and CO emissions following two C + N application events in two managed grassland ecosystems with loam and sandy loam soils.

Full Inversion Tillage (FIT) during pasture renewal as a potential management strategy for enhanced carbon sequestration and storage in Irish grassland soils.

It has been suggested that the sequestration of CO by agricultural soils offers a means to reduce atmospheric greenhouse gas (GHG) concentrations and in turn mitigate the impacts of climate change. Carbon sequestration by grassland soils, which account for more than 60% of agricultural land use in Ireland, could contribute to a successful net reduction of atmospheric GHG emissions in accordance with the COP21 Paris Agreement. However, current estimates of soil carbon sequestration are variable and it is likely that many permanent grasslands are close to saturation.

Uncertainties in direct NO emissions from grazing ruminant excreta (EF) in national greenhouse gas inventories.

Excreta deposition onto pasture, range and paddocks (PRP) by grazing ruminant constitute a source of nitrous oxide (NO), a potent greenhouse gas (GHG). These emissions must be reported in national GHG inventories, and their estimation is based on the application of an emission factor, EF (proportion of nitrogen (N) deposited to the soil through ruminant excreta, which is emitted as NO) Depending on local data available, countries use various EFs and approaches to estimate NO emissions from grazing ruminant excreta. Based on ten case study countries, this review aims to highlight the uncertainties around the methods used to account for these emissions in their national GHG inventories, and to discuss the efforts undertaken for considering factors of variation in the calculation of emissions.

Ammonia and nitrous oxide emission factors for excreta deposited by livestock and land-applied manure.

Manure application to land and deposition of urine and dung by grazing animals are major sources of ammonia (NH ) and nitrous oxide (N O) emissions. Using data on NH and N O emissions following land-applied manures and excreta deposited during grazing, emission factors (EFs) disaggregated by climate zone were developed, and the effects of mitigation strategies were evaluated. The NH data represent emissions from cattle and swine manures in temperate wet climates, and the N O data include cattle, sheep, and swine manure emissions in temperate wet/dry and tropical wet/dry climates.

Beneficial effects of multi-species mixtures on NO emissions from intensively managed grassland swards.

In a field experiment, annual nitrous oxide (NO) emissions and grassland yield were measured across different plant communities, comprising systematically varying combinations of monocultures and mixtures of three functional groups (FG): grasses (Lolium perenne, Phleum pratense), legumes (Trifolium pratense, Trifolium repens) and herbs (Cichorium intybus, Plantago lanceolata). Plots received 150 kg ha year nitrogen (N) (150 N), except L. perenne monocultures which received two N levels: 150 N and 300 N.

Source partitioning using NO isotopomers and soil WFPS to establish dominant NO production pathways from different pasture sward compositions.

Nitrous oxide (NO) is a potent greenhouse gas (GHG) emitted from agricultural soils and is influenced by nitrogen (N) fertiliser management and weather and soil conditions. Source partitioning NO emissions related to management practices and soil conditions could suggest effective mitigation strategies. Multispecies swards can maintain herbage yields at reduced N fertiliser rates compared to grass monocultures and may reduce N losses to the wider environment.

DATAMAN: A global database of nitrous oxide and ammonia emission factors for excreta deposited by livestock and land-applied manure.

Nitrous oxide (N O), ammonia (NH ), and methane (CH ) emissions from the manure management chain of livestock production systems are important contributors to greenhouse gases (GHGs) and NH emitted by human activities. Several studies have evaluated manure-related emissions and associated key variables at regional, national, or continental scales. However, there have been few studies focusing on the drivers of these emissions using a global dataset.

Sward composition and soil moisture conditions affect nitrous oxide emissions and soil nitrogen dynamics following urea-nitrogen application.

Increased emissions of NO, a potent greenhouse gas (GHG), from agricultural soils is a major concern for the sustainability of grassland agriculture. Emissions of NO are closely associated with the rates and forms of N fertilisers applied as well as prevailing weather and soil conditions. Evidence suggests that multispecies swards require less fertiliser N input, and may cycle N differently, thus reducing N loss to the environment.