Grazing behaviour, urine composition and soil properties are key drivers of nitrous oxide emissions from livestock urine in the uplands (Uplands-N2O)

Lead Research Organisation: Bangor University
Department Name: Sch of Environment and Natural Resources

Abstract

The aim of this project is to develop an improved understanding of the spatial and temporal interactions between grazing behaviour, forage selection, urine composition and edaphic conditions and to use the insights garnered to improve the accuracy of nitrous oxide (N2O) emission estimates from contrasting semi-improved and unimproved upland grazed pastures in the UK. This is of major importance because (1) urine patches are a significant source of N2O; ca. 19% of the total N2O losses from agriculture, and (2) N2O losses from upland systems are highly uncertain. Current methods of estimating emissions from urine patches ignore the effect that livestock diet, soil type, soil physico-chemical properties and climate have on N2O fluxes. For example, urine N content varies with protein intake, and the metabolic product in the urine (known to affect N2O production) is affected by what livestock graze. Vegetation in different upland areas varies enormously, with diet selection operating in both systems. Hence it is important to link urine composition to animal movement and diet selection.

Soils in the uplands are dominated by peats and podzols with high carbon content and low pH, influenced by cool, wet climates and topography. These factors will also exert systematic controls on rates of N2O fluxes which are likely to be exacerbated following urine deposition. Moreover, the vegetation in different upland areas influences stocking densities and the consequent potential for urine patch overlap, resulting in disproportionate N2O emissions in areas receiving high N loading rates. Soil in these areas can become compacted due to livestock trampling, reducing air filled pore space, increasing anaerobicity and enhancing conditions for N2O losses via denitrification. It is, therefore, essential to establish the relationships between urine composition (the result of grazing preference), soil type, soil physico-chemical properties (which might be influenced by topographic effects on hydrology) and climate in order to generate improved N2O flux estimates, emission factors and carbon footprints from livestock production.

We will address these knowledge gaps through a combination of:
i) Fine-scale mapping of 'static' factors controlling N2O fluxes, i.e. topography, soil type, vegetation type and soil compaction, using high resolution remotely sensed imaging over contrasting upland areas
ii) Mapping of the 'mobile' factors controlling N2O fluxes, i.e. measuring livestock movement and grazing patterns in these two grassland systems using GPS collars, and observing urination events
iii) Collection of urine from sheep grazing dominant vegetation types and relating the urine composition to dietary preference
iv) Measurement of N2O fluxes following the application of collected urine to soil under typical vegetation types, and calculation of robust urine direct N2O emission factors over a 12 month period
v) Conducting controlled replicated experiments to explore the factors controlling N2O fluxes from soil from contrasting field sites (e.g. changing urine composition, water content and levels of compaction)
vi) Developing a novel model framework to predict the statistics of animal occupancy and to integrate predicted urine emissions with spatial and temporal information of landscape-scale explanatory factors in order to quantify aggregate N2O emissions for upland pastures

Uniquely, we will gain improved understanding of the spatial and temporal interactions between grazing patterns, forage choice, urine composition, soil and climate factors and N2O fluxes in upland systems. Outputs from the project will be compared with IPCC Tier 1 and Tier 2 approaches for estimating N2O emissions from livestock grazing in the UK and provide the basis for robust and scientifically defensible alterations to standard inventory approaches, if required, along with inputs to carbon footprinting and to the spatial targeting of mitigation practices.

Planned Impact

The outputs of this research will impact on society and the economy by influencing the:
SCIENTIFIC COMMUNITY: Our research will inform scientists working in several areas of research e.g. livestock behaviour, grazing management, ruminant nutrition, GHG emissions and modelling. The unique synthesis of the information generated by this project bridges the gap between research which focusses on dietary preference, food production and nutrient/energy balances, and research which focusses on quantifying the impact of soil amendments on N2O emissions from soils. It will link dietary preferences to soil function in contrasting grassland upland pastures using monitoring and observation, mapping, field and laboratory based measurements, all synthesised in a spatially explicit model.
The project strengthens existing research links on GHG emissions and mitigation between Bangor and RRes-North Wyke, and initiates a new collaboration with Cranfield and Leicester Universities in highly complementary disciplines. Chadwick represents the UK in the Livestock Research Group of the Global Research Alliance on Agricultural GHGs. He also leads the UK GHG Platform project to Improve the Agricultural Greenhouse Gas Inventory for Nitrous oxide (http://www.ghgplatform.org.uk/). Cardenas is responsible for the collation and submission of the UK Agriculture GHG inventory. She is also part of the consortium project to deliver the new Tier 2 GHG inventory for agriculture. Perotto-Baldivieso has worked with GPS collars and spatial analysis in the Caribbean and the United States. He has been the president of the International Affairs Committee for the Society for Range Management (2008-2009). We will raise awareness of this project through these networks, and demonstrate the importance of moving to a more sophisticated approach to reflect the effect of dietary preference on direct N2O emissions.
Participation at International conferences will help communicate results and generate interest for future work. The Nitrogen Workshop (in2016/7) attracts researchers mostly from Europe on all aspects of nitrogen cycling, whilst the International Greenhouse Gases and Animal Agriculture Conference in Melbourne (2016) represent a tremendous opportunity to discuss initial research findings and project goals with researchers from outside Europe.
POLICY COMMUNITY: Results from monitoring of livestock movement at the field and landscape scale, offers the opportunity to explore where targeted mitigation strategies could be cost-effective, e.g. through the use of inhibitors to reduce N2O emissions from hot-spots, or through the frequent moving of feeders. Results could prove N2O emission factors (EFs) from urine to be much lower/larger than the IPCC value due to interactions of urine composition, soil properties and climate, with important policy implications re: improving national inventories.
As part of the GHG Platform, Chadwick and Cardenas are regularly invited to give oral presentations to various audiences; policy makers, farmers and industry, providing opportunities to communicate the findings of this project.
INDUSTRY: Research findings will be communicated to the livestock industry, which has set its own targets for GHG mitigation. Our results will be of interest to them, from an EF point of view, but also in terms of development of mitigation strategies, and in the carbon foot printing of their products for comparison with competing countries, such as New Zealand lamb.
WIDER COMMUNITY: A web page on the Bangor website will provide information on the project and its results. Different aspects of the project will be used for teaching at Bangor, Cranfield and Leicester, generating student projects, and will be presented at annual 'tours' of experiments at RRes-North Wyke and Bangor. We will also feature the project in School Science Week, using visualisation of animal 'movement's to stimulate wider discussion about livestock production and the environment.

Publications


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Marsden K (2016) The urine patch diffusional area: An important N2O source? in Soil Biology and Biochemistry
 
Description Early indications are that the nitrous oxide emissions from the urine patches in the upland appear to be low (at least following the first two experiments). We are investigating why this might be, and what the fate of the deposited urinary nitrogen is.

We have also detected urination events using accelerometers attacehd to the sheep.
Exploitation Route These are interim results, as we are only part way throught the experimental part of the project. Once we are confident in the results we will make them available to others.
Sectors Agriculture, Food and Drink,Digital/Communication/Information Technologies (including Software),Electronics,Environment,Government, Democracy and Justice
 
Description @UplandsN2O twitter account set up 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact We recentyl set up an @UplandsN2O twitter account
Year(s) Of Engagement Activity 2017
 
Description Capital FM (Wales). Marsden - Radio Interview 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Radio station Capital FM (Wales) interviewed the new post-doc at Bangor University, Karina Marsden about greenhouse gas emissions in Wales, and especially the role of urine patches of grazing livestock in the uplands.
Year(s) Of Engagement Activity 2015
 
Description GGAA2016, Melbourne Oral presentation and Abstract Marsden et al (2016) Disentangling the effect of sheep urine patch size and N loading rate on cumulative N2O emissions. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Kara Marsden (Bangor Univ post-doc) presented at the Greenhouse Gases and Animal Agriculture Confernece in January 2016, Melbourne. The presentation and abstract was called: Disentangling the effect of sheep urine patch size and N loading rate on cumulative N2O emissions, and included slides showcasing the plans for the Uplands-N2O project.
Year(s) Of Engagement Activity 2016
 
Description Global Farm Platform Conference Poster and Abstract: Cardenas et al (2016) Grazing behaviour, urine composition and soil properties are key drivers of nitrous oxide emissions from livestock urine in the uplands (Uplands-N2O) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Laura Cardenas (Co-I at Rothamsted Research) presented a poster and abstract at the Global Farm Platform Conference, Grazing behaviour, urine composition and soil properties are key drivers of nitrous oxide emissions from livestock urine in the uplands (Uplands-N2O)
Year(s) Of Engagement Activity 2016
 
Description N Workshop (Sweden) Poster and abstract: Cardenas et al. (2016) Grazing behaviour, urine composition and soil properties are key drivers of nitrous oxide emissions from livestock urine in extensive systems (Uplands-N2O) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Laura Cardenas (Co-I at Rothamsted Research) presented a poster and abstract at the Nitrogen Workshop (Sweden). Title: Grazing behaviour, urine composition and soil properties are key drivers of nitrous oxide emissions from livestock urine in extensive systems (Uplands-N2O)
Year(s) Of Engagement Activity 2016
 
Description Press releases: No laughing matter: new research to study nitrous oxide from sheep urine patches in the uplands 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Media (as a channel to the public)
Results and Impact Press releases were made by the individual project partners. This resulted in a number of articles in local press.
Year(s) Of Engagement Activity 2015
 
Description RDF NRN Workshop on Sensors and Sensing Technologies. Poster Marsden et al (2016). Grazing behaviour, urine composition and soil properties are key drivers of nitrous oxide emissions from livestock urine in extensive systems (Uplands-N2O) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Kara Marsden (post-doc at Bangor University) presented a poster at an RDF NRN Workshop on Sensors and Sensing Technologies, at Henfaes REsearch Centre (June 2016). Grazing behaviour, urine composition and soil properties are key drivers of nitrous oxide emissions from livestock urine in extensive systems (Uplands-N2O)
Year(s) Of Engagement Activity 2016
 
Description Rory Wilson demonstrated daily diary tags and ability to detect urination events in sheep at the RDF NRN Sensors and Sensing Technologies Workshop, Henfaes Research Centre, Bangor in 2016 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Rory Wilson demonstrated daily diary tags and ability to detect urination events in sheep at the RDF NRN Sensors and Sensing Technologies Workshop, Henfaes Research Centre, Bangor in June 2016. This Workshop was aimed at bringing together developers and users of sensors to optimise resource use in the agricultural landscape. IF focussed on livestock systems.
Year(s) Of Engagement Activity 2016
 
Description Soil Security Programme news item: Marsden (2016) Improving the accuracy of nitrous oxide (N2O) emission estimates from extensively grazed grassland systems. 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Kara Marsden, the Bangor University post-doc, offered a news item for the Soil Security Programme newsletter. It was called: Improving the accuracy of nitrous oxide (N2O) emission estimates from extensively grazed grassland systems.
Year(s) Of Engagement Activity 2016
 
Description Uplands-N2O website was created: http://uplands-n2o.bangor.ac.uk/. 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact The Uplands-N2O website: http://uplands-n2o.bangor.ac.uk/, was set up to increase awareness of the project and provide regular updates of results.
Year(s) Of Engagement Activity 2016
URL http://uplands-n2o.bangor.ac.uk/
 
Description Yorkshire Dales LFA Farmer Group visit to Henfaes Research Centre - Summer 2016 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact A group of Yorkshire Dale LFA farmers visited HEnfaes Research Centre, BAngor University, and we took them to see the Uplands-N2O field site where N2O emissions were being measured from urine patches. This stimulated discussion about carbons storage in soils and carbon footprinting of lamb from upland systems.
Year(s) Of Engagement Activity 2016