Title: Evaluation of ammonia and greenhouse gas emissions from the livestock production sector in Northern Ireland (DBS-90-17).

Project Team: Tianhai Yan, Conrad Ferris, Elizabeth Ball, Rachael Carolan, Rodrigo Olave, Dario Fornara and Alan Gordon.

Background:

Ammonia emissions are a particularly significant issue in Northern Ireland since per capita emissions are approximately four times higher here than in the rest of the UK. This reflects how NI differs from other parts of the UK as a food exporting region which is economically reliant on the agri-food sector and has relatively little cereal farming. Unlike Greenhouse Gases which impact on a global scale, the repercussions from relatively high ammonia emissions are localised and usually felt within our own region. The ammonia which is emitted from our farms is deposited back on land locally, including designated sites, and priority habitats, potentially causing environmental damage 

 

The UK inventory for ammonia emissions from Agriculture uses UK-averaged-emission factors to estimate ammonia emissions from livestock enterprises in Northern Ireland. However, this approach may not be fully applicable to farming conditions in Northern Ireland. For example, in the development of Nitrate Directives in Northern Ireland, we found that dairy cows in Northern Ireland produced less manure N than those in the Great Britain (91 vs. 108 kg/head per year) because our cows produced less milk. It is therefore logical to suggest that ammonia emissions (kg/head/year) from dairy production in Northern Ireland should be lower than those in the Great Britain. A second example relates to the straw bedding, unlike in England, cattle and pigs in Northern Ireland are managed mainly in slurry-based systems because there is a general lack of straw for bedded systems in Northern Ireland. Additionally, it has been demonstrated that the nutrient content of broiler litter and manure from other production systems within Northern Ireland is different from current regulation values and this lends support to suggest that air emission factors may no longer be appropriate. Furthermore, due to the change in heating systems in NI poultry houses, the DM of litter and manure has increased and it is highly probable that ammonia emissions have been reduced as a result, however the magnitude of change is not possible to predict due to a lack of comparable data in the literature. Therefore, there is an urgent need to develop ammonia emission data for livestock production and manure management in Northern Ireland. 

 

The present proposal is therefore designed to address the above knowledge gap with the objectives to develop ammonia emission data under our own farm conditions which can be used to robustly quantify ammonia emissions from livestock production and manure management in Northern Ireland. The emissions of greenhouse gases (CO2, CH4 and N2O) from manure management will also be measured in the present project. In addition, other air emissions including particulate matter will be assessed from broiler production. The outcome of this project will provide policy makers and livestock industries with the scientific evidence to develop robust mitigation strategies to reduce ammonia and GHG emissions from livestock production in Northern Ireland.

 

Objectives:

The aim of this project is to increase the scientific robustness of ammonia emission factors and investigate mitigation strategies to reduce ammonia emissions for the livestock sectors in NI. While in measuring ammonia emissions from manure management of livestock production, we will also measure effects of different feeding and management factors on greenhouse gases (CO2, CH4 and N2O) emissions from manure storage. Such information is important for providing the baseline environmental footprint associated with livestock production in Northern Ireland. 

To support this aim, this project has the following objectives. 

 

1. Investigation of dietary factors to reduce ammonia emissions for dairy cattle, beef cattle, sheep and pig sectors 

1a. Collecting samples of faeces and urine from dairy cows, beef cattle, sheep and pigs. The experimental animals will be offered different diets (e.g., variation in crude protein levels, and ingredient composition). The samples for grazing cattle and sheep will be collected in simulating zero-grazing studies.  

1b. Measuring ammonia and GHG (CO2, CH4 and N2O) emissions from slurry using respiration calorimeter chambers. The samples from zero-grazing studies for cattle and sheep will also be measured in grazing fields in the simulated-grazing studies.  

1c. Developing models using data collected in the present study to identify mitigation strategies to reduce ammonia and GHG emissions for the livestock sectors in Northern Ireland and to predict ammonia and GHG emissions from manure management.  

 

2. Development of robust ammonia emission factors for the poultry sector in NI  

2a.Establish up-to-date emission factors for NH3 and other air emissions from NI production systems to “sharpen the inventory”. 

2b.Quantify the relationship between poultry litter DM and NH3 and other air emissions.  

 

3 Investigation of relationships between slurry and fertiliser applications and ‘dry’ and ‘wet’ ammonia deposition monitored at AFBI Hillsborough