7LMS0207 Agriculture and Environment Assignment
Module Code: 7LMS0207
Agriculture and Environment
Introduction, explanation and guidance for Assignment 2:
Development of a carbon footprint for a farm.
Module Coordinator: Dr Doug Warner
For MSc/PgD/PgC students on the MSc in Environmental Management for Agriculture pathway, full-time and part-time by distance learning in the workplace, as well as students sitting this module as a standalone module.
April 2023
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©University of Hertfordshire Higher Education Corporation (2023)
Contents…………………………………………………………………………………………….. 3
1.0 Introduction…………………………………………………………………………………. 4
2.0 Report……………………………………………………………………………………….. 5
3.0 Management scenarios…………………………………………………………………….. 7
5.0 CFT screenshots (setting up)……………………………………………………………. 14
Refer also to the lectures ‘Introduction to different farming systems, environmental pollutants and impacts’ and ‘Greenhouse gas emissions and carbon sequestration’.
For Assignment 2 you are required to input crop management data (provided in sections 3.1 and 3.2) based on actual crop / livestock production scenarios into the COOL Farm Tool® (CFT) https://coolfarmtool.org/ agricultural greenhouse gas calculator tool. Create an account (select green button top right hand side ‘Go to CFT’ – Create account – enter your details – for Organisation add ‘UoH’ – User type select ‘Academic’ – Country select ‘United Kingdom’ – agree to terms then Register).
Then select the downward arrow to the right of your username at the top of the screen (next to ?Help)
– select ‘Farm settings’ – enter the data as in the screenshot below then select Save:
You are now ready to use the tool and enter data. Hover the mouse icon over ‘New assessment’ – select ‘All crops’ – ‘Greenhouse gas’ then enter the data for Rapeseed provided in section 3.1. When you have completed this and saved it you can then create a second scenario, this time for livestock -go to ‘New assessment’ select ‘Other livestock’ – select ‘Cattle’ and enter the data provided in section 3.2.
1500 word assignment due Tue 9th May 2023
Please structure the assignment in report format to include:
- Summary (key emission sources in descending order of importance)
- Introduction
- Methods
- Results
- Discussion
- Conclusions
Refer to Departmental guidelines for e.g. reference format.
What are the key sources of emissions for each scenario? Focus in descending order of what you consider to be importance.
What are the reasons / mechanisms behind these emission sources (please make reference to the published literature – some key references are provided at the end but undertake your own literature search in e.g. Google Scholar).
Is the output you have generated for each farm with respect to dominant emissions sources on each crop type or livestock enterprise in agreement with other studies of this nature identified in your literature review? If not, are there any reasons e.g. differences in soil type, cultivation regime, manure storage method etc.
Are there any improvements that could be made to the scenarios e.g. source of nitrogen fertiliser or method of manure storage? Please give reasons.
Some farm operations may not as yet be included in the tool (it is continually being developed). Make a note of anything that you feel is missing and include as recommendations for improvement in a critical reflection of the tool to be included in the Discussion. Think about what additional sources of emissions (e.g. other farm operations, soil conditions, agro-chemicals) might be added to the tool.
The word limit is 1500 words. The word count excludes table content so you are advised to use them (and graphs) to summarise data – ensure you make reference to them in the text.
Example small sections of text for example scenarios, do not include it in the report, use your own: Summary
Overview of key findings in order of importance
The greenhouse gas emissions, expressed as tonnes of carbon dioxide equivalent (t CO2e), have been assessed for three agricultural production scenarios: winter oilseed rape, soft fruit and cattle. The main source of emissions were nitrogen fertiliser manufacture and fate in winter oilseed rape crops, enteric methane produced by cattle and deep tillage operations required for bed formation in soft fruit crops…
Introduction
Overview of the issue e.g. climate change, why it is important, how does agriculture contribute, what is unique about agriculture in terms of its contribution to greenhouse gas emissions…
Key greenhouse gas emissions from agricultural systems include carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) (Smith et al., 2019). Agriculture is a key source of CH4 and N2O, contributing over 50% of the total anthropogenic emissions of these two greenhouse gases globally (Smith and Ostle, 2020). Agricultural greenhouse gas emissions are likely to increase in the future as the global population and the resultant demand for food increases (Liu et al, 2019). There is a need therefore to reduce greenhouse gas emissions per unit of commodity produced…
Methods
A brief summary of what was done e.g.
The Cool Farm Tool version CFT v0.11.39 (2021) was used to calculate the CO2 equivalent from three agricultural production scenarios, summarised in Tables 1, 2 and 3…
Results
Briefly describe the key outputs from the graphs, focus on the farm operations with the highest sources of emissions for each scenario first, how do the scenarios compare.
The key greenhouse gas emissions for winter oilseed rape as calculated by the CFT are summarised in Figure 1…
Figure 1 shows that nitrogen fertiliser is the largest contributor to greenhouse gas emissions in spring wheat production, both during its manufacture and due to N2O emissions from soil. Other key sources of emissions in spring wheat include…
Discussion
For the emission sources provided by the CFT for the two scenarios think about what the type of emission is (CO2, CH4 or N2O), how e.g. the method of manure storage or dietary components (grass compared to cereal grain / wheat) may affect the quantity of emissions. How do inputs such as fertiliser and the type of fertiliser impact emissions. Any other key sources? What are the underlying reasons – search the literature. Critically discuss your results i.e. compare the data produced by the CFT with the emissions reported in the published literature (focus on the farm operations with the highest sources of emissions for each scenario first as these are the most important), do they agree, if not are there any reasons why not.
Tzilivakis et al (2005a) report mean UK greenhouse gas emissions from sugar beet production of 1.25 t CO2e ha-1. The sugar beet scenario evaluated in this assessment is larger (2.50 t CO2e ha-1) mainly due to differences in the nitrogen fertiliser application rate (150 kg N ha-1 as opposed to 100 kg N ha– 1). This additional nitrogen fertiliser increased both the emission of N2O from soils and from the fertiliser manufacture process. Supplementary nitrogen is a key factor in determining the overall greenhouse gas emissions associated with agricultural crop production also noted by other studies such as Goulding et al. (2018).
Nitrous oxide (N2O) is a potent greenhouse produced via the processes of nitrification and denitrification (Hillier et al, 2017) and was, according to the CFT, a key contributor to the total greenhouse gas emissions derived from oilseed rape. This observation is supported by several authors in the published literature. A total of 2 kg of N2O ha-1 was released, which agrees broadly with Goulding et al. (2018) who state a range in N2O emissions of between 2- 4 kg ha-1 in response to supplementary nutrient application using ammonium nitrate fertiliser. The figure obtained from the CFT is at the lower end of the range cited by Goulding et al. (2018), due partly to the sandy soil in this scenario requiring a lower input of nitrogen compared to the deep clay soils evaluated by Goulding et al. (2018).
Conclusions
What are the main findings, the key things that you think are important for the scenarios evaluated.
You are provided with a crop management scenarios from two different sectors: arable and livestock. Please complete each scenario so that you have a total of two profiles in the CFT, one from each of the two different sectors.
Arable
Rapeseed
Livestock
Semi-improved grassland: cattle
They are based on situations applicable in the UK and northern Europe, but with modifications to allow potential for management practices to be improved. You are required to create farm profiles in the CFT for each of the two selected scenarios from each sector and calculate the carbon footprint of the two scenarios chosen.
For the arable and horticulture scenarios the CFT has seven data input sheets:
- Crop
- Soil
- Inputs
- Fuel and Energy
- Irrigation
- Carbon
- Transport
The focus of the report is ‘on-farm’ emissions so transport is not included. Irrigation may not be required for arable crops. There is no assumed land use change so the ‘Carbon’ sheet does not require completion.
For livestock (use juvenile phase only) there are four data input sheets:
- General
- Herd and feed
- Energy and processing
- Transport
After you have entered your crop or livestock management data and move onto data input sheet 7 (or data input sheet 4 for livestock) and select ‘save’ you will be provided with detailed output in
table and graphical format (scroll down the page) as shown in Figures 1 and 2. It provides information on the contribution of each category, individual greenhouse gases and further breakdowns by e.g. machinery type. This can be extracted to construct your own graphs in e.g. Excel (for example an overview graph comparing all scenarios together).
For guidance an example emissions profile for a crop scenario is summarised below. The main thing is that you interpret the graphs / output that you have produced linking to the inputs provided in Sections 3.1 and 3.2 of the assignment brief.
Figure 1. Example of detailed CFT output.
Note the breakdown into the individual greenhouse gases CO2, N2O and CH4. [k = 1000 or 1 tonne]
Figure 2. Example of detailed CFT output.
You are advised to make all calculations for 1 ha for each crop or livestock type and area (it will aid interpretation of results and can be compared directly with the output reported in the peer reviewed literature).
Ensure you check all units i.e. whether g, kg or tonnes and convert them as necessary. If you are unable to find an appropriate place in the CFT to enter data please make a note of it and suggest it as a potential improvement to the tool.
- Arable scenario. Oilseed rape (Rapeseed)
Sand soil, low rainfall zone, SOM 2.0%, dry soil, good drainage, pH 6.5.
The field operations, total nitrogen and pesticides per ha per year to a crop of rapeseed on the farm are given in Table 1.
They are applied to 100% of each ha on a Soil Nitrogen Supply index of 1.
Nitrogen and P2O5 fertilisers are sourced from Europe, K2O and lime uses the World 2014 average. Nitrogen is applied by broadcast application. P and K are incorporated.
Farm machinery uses diesel – ignore section 4.1, just use CFT ‘4.2 Field operations energy use’ for cultivations, spraying etc.
Fungicide and insecticide applications are classed as ‘biocide spraying’. Crop protection products are applied at 0.25 kg ha-1, 50% active ingredient for each product.
There are no co-products, no irrigation, no waste water, no land use changes.
Table 1. Summary of inputs to rapeseed.
| Activity | Product and active ingredient per ha |
| lime | ground limestone (55% CaCO3) 750 kg product |
| P fertiliser base maintenance + K fertiliser base maintenance | 80 kg P2O5 units as triple superphosphate 48% P2O5 + 70 kg K2O units as muriate of potash |
| Tillage – moldboard plough | |
| Tillage – combine harrow (harrow + seed drill) | 5 kg seed ha-1 |
| crop protection – post emergence | herbicide 0.25 kg ha-1, 50% ai – spraying |
| N fertiliser | 30 kg N units as ammonium nitrate 33.5% N (granulated) |
| N fertiliser | 90 kg N units as ammonium nitrate 33.5% N (granulated) |
| N fertiliser | 100 kg N units as ammonium nitrate 33.5% N (granulated) |
| crop protection – post emergence | fungicide 0.25 kg ha-1, 50% ai – biocide spraying |
| crop protection – post emergence | fungicide 0.25 kg ha-1, 50% ai – biocide spraying |
| crop protection – post emergence | insecticide 0.25 kg ha-1, 50% ai – biocide spraying |
| crop protection – post emergence | fungicide 0.25 kg ha-1, 50% ai – biocide spraying |
| combine harvester | farm-gate yield 3.0 t ha-1 (total yield 3.5 t ha-1) |
| crop residues ‘Left distributed on field’ (6.61 t ha-1) | |
| drying (to 85% dry matter) | |
| transport off farm HGV >3.5 t 150 km |
Think about how inputs such as fertiliser and the type of fertiliser impact greenhouse gas emissions and the type of emission (CO2, CH4 or N2O).
Livestock Scenario. Other livestock – cattle
Evaluation of the juvenile phase only, 1 animal for 2 years.
Select ‘Other livestock’ then ‘Cattle’ in the CFT
Cattle are housed for 151 days per year (between 1st November and 1st April) and grazed on medium quality pasture for the remainder, a 41%:59% split.
Solid manures are stored in unconfined piles or stacks at an ambient temperature of <10oC during the housing period.
No co-products or waste water.
Table 2. Summary of inputs to semi-improved grassland per ha.
| Date | Activity | Product and active ingredient per ha |
| stocking rate | 1 animal, 500 kg | |
| daily dry matter intake – juvenile | 3 kg per animal per day | |
| 1st November to 1st April | housing – manure storage | solid |
| 1st November to 1st April | Facility (processing) housing | 250 kwh electricity (grid) |
| 1st April to 30th October | grazing (pasture) | medium quality – 60% of total nutrition as temperate grassland: permanent grass |
| supplementary feed | 35% of total nutrition as fodder legumes | |
| supplementary feed | 5% of total nutrition as wheat | |
| finished product | 450 kg | |
| transport | 300 miles by HGV truck >3.5t | |
Suggested reading and other resources
CALU – Centre for Alternative Land Use (2007) Managing Energy and Carbon. The farmer’s guide to energy audits. University of Bangor, Wales. www.calu.bangor.ac.uk.
Lillywhite, R.D., Chandler, D., Grant, W., Lewis, K., Firth, C., Schmutz, U. and Halpin, D. (2007) Environmental footprint and sustainability of horticulture (including potatoes) – A comparison with other agricultural sectors. 1 – 159, Defra, UK.
Moorby, J.M., Chadwick, D.R., Scholefield, D., Chambers, B.J. and Williams, J.R. (2007) A review of best practice for reducing greenhouse gases. Defra project report AC0206.
Monteny, G., Bannink, A. and Chadwick, D. (2006) Greenhouse gas abatement strategies for animal husbandry.
Agriculture, Ecosystems and Environment, 112, 163-170.
Newell Price, J.P., Harris, D., Taylor, M., Williams, J.R., Anthony, S.G., Duethmann, D., Gooday, R.D., Lord, E.I., Chambers, B.J., Chadwick, D.R., Misselbrook, T.H. (2011). An Inventory of Mitigation Methods and Guide to their Effects on Diffuse Water Pollution, Greenhouse Gas Emissions and Ammonia Emissions from Agriculture. Prepared as part of Defra Project WQ0106.
Tzilivakis, J., Jaggard, K., Lewis, K.A., May, M. & Warner, D.J. (2005a) An assessment of the energy inputs and greenhouse gas emissions in sugar beet (Beta vulgaris) production in the UK. Agricultural Systems, 85, 101- 119.
Warner, D.J. Davies, M., Hipps, N., Osborne, N., Tzilivakis, J. and Lewis, K.A. (2010) Greenhouse gas emissions and energy use in UK grown short-day strawberry (Fragaria xananassa) crops. Journal of Agricultural Science,148, 667–681.
Williams, A.G., Audsley, E. and Sandars, D.L. (2006) Determining the environmental burdens and resource use in the production of agricultural and horticultural commodities. Main Report. Defra Research Project IS0205. Bedford: Cranfield University and Defra.
Brentrup, F., Küsters, J., Kuhlmann, H. and Lammel, J. (2004) Environmental impact assessment of agricultural production systems using the life cycle assessment methodology I. Theoretical concept of a LCA method tailored to crop production. European Journal of Agronomy, 20, 247–264.
Dalgaard, T., Halberg, N. and Porter, R.P. (2001) A model for fossil energy use in Danish agriculture used to compare organic and conventional farming. Agriculture, Ecosystems and Environment, 87, 51-65.
De Vries, W., Kros, J., Oenema, O. and de Klein, J. (2003) Uncertainties in the fate of nitrogen II: A quantitative assessment of the uncertainties in major nitrogen fluxes in the Netherlands. Nutrient Cycling in Agroecosystems, 66, 71-102.
Dobbie, K.E. and Smith, K.A. (2003) Nitrous oxide emission factors for agricultural soils in Great Britain: the impact of soil water-filled pore space and other controlling variables. Global Change Biology, 9, 204-218.
Freibauer, A. (2003) Regionalised inventory of biogenic greenhouse gas emissions from European agriculture.
European Journal of Agronomy, 19, 135-160
IPCC – Intergovernmental Panel on Climate Change (2014). AR5 Synthesis Report: Climate Change 2014. IPCC: Geneva, Switzerland. Available from https://www.ipcc.ch/report/ar5/syr/.
Louwagie, G., Gay, S. H. and Burrell, A. (2009) Sustainable Agriculture and Soil Conservation (SoCo). Final report. EUR 23820 EN – 2009. DG Agriculture and Rural Development, European Commission.
Machefert, S.E., Dise, N.B., Goulding, K.W.T. and Whitehead, P.G. (2002) Nitrous oxide emission from a range of land uses across Europe. Hydrology and Earth System Sciences, 6, 325-337.
Milà i Canals, L., Cowell, S, J., Sim, S. and Basson, L., (2007) Comparing domestic versus imported apples: a focus on energy use. Environmental Science Pollution Research, 14, 338-344.
A good general text (available in the LRC) is:
Merrington, G., Winder, L., Parkinson, R., Redman, M. (2002). Agricultural Pollution: Environmental Problems and Practical Solutions. Spon Press, London (Taylor and Francis Group).
Research reports, industry guidance and latest developments are located on the following websites:
- Department for Environment, Food and Rural Affairs (Defra): http://www.defra.gov.uk/
- Environment Agency: http://www.environment-agency.gov.uk/
- European Commission – Joint Research Centre: http://ec.europa.eu/dgs/jrc/index.cfm?id=5270
- Natural England: http://www.naturalengland.org.uk/
5.0 CFT screenshots (setting up)
Select ‘Go to CFT’ – ‘Create account’ – – for Organisation type ‘UoH’ – under user type select ‘Academic’