Update from the Signpost Demonstration Cattle Farmers

Siobhán Kavanagh¹, Tom O’Dwyer², Brian Moran³ and Cathal Buckley³

¹Teagasc, Kells Road, Kilkenny

²Teagasc, Animal and Grassland Research & Innovation Centre, Moorepark, Fermoy, Co. Cork

³Teagasc, Mellows Campus, Athenry, Co. Galway

Summary

• The Signpost cattle farmers have adopted many of the climate mitigation technologies recommended by Teagasc, but there is still scope to reduce greenhouse gas (GHG) and ammonia emissions on these farms.

• Nitrogen fertiliser use has decreased by 22% on the Signpost farms and 48% of it is now applied as NBPT-Urea (Protected Urea).

• Signpost cattle farms are finishing bulls, steers and heifers at 17.7, 23.8 and 22.5 months, respectively.

• It is advised that all cattle farmers sign up for the Signpost Advisory Programme to identify ways to reduce gaseous emissions.

Background

The Signpost Programme is designed to support and enable beef farmers to farm more sustainably. The demonstration farmers are the early-adopters of key technologies to reduce greenhouse gas (GHG) emissions.  They are following the “12 Steps to Reduce Gaseous Emissions” which includes technologies such as reducing reliance on chemical nitrogen (N) fertiliser, increasing the length of the grazing season, improving animal health, improving animal breeding performance, and reducing animal age at first-calving and age at finishing.  This paper aims to benchmark the uptake of these recommended climate mitigation practices for the beef farms participating in the programme. These Signpost beef farmers were not selected to be representative of the “typical beef farmer” and operate at a higher level of productivity and profitability relative to the average National Farm Survey beef farmers.  The Signpost beef demonstration farmers are part of the Future Beef Suckler Programme or the Dairy Beef 500 programme.  

Farm performance

There was a high level of technical performance on the Signpost cattle farms in 2023 with an average beef live weight output of 689 kg/hectare (ha) on the suckler beef farms and 1303 kg/ha on the dairy-beef farms (Table 1).  Average chemical N fertiliser use across the suckler beef and dairy-beef farms was 85 kg N/ha and average concentrates fed per livestock unit (LU) was 708 kg. This level of concentrate feeding was 27% greater than 2022, with the increase attributed to the inclement weather conditions that prevailed, particularly in the second half of the year.  Beef live weight output/ha decreased in 2023 compared to 2022, particularly on the dairy-beef farms where stocking rate declined from 2.62 to 2.44 LU/ha. The challenging weather conditions in 2023 led to poor grazing conditions, reduced cattle growth rates and difficulty in finishing animals.  On average, Family Farm Income was €516/ha during 2023, which is a slight decrease from 2022 (€587/ha).

Table 1. Performance of Signpost cattle farms over three years

Teagasc 12 Steps to Reduce Gaseous Emissions

Teagasc have identified 12 key steps to reducing gaseous emissions on cattle farms.  Significant progress has been made by Signpost Cattle farmers to adopt key technologies to reduce emissions (Table 2). 

Steps 1-6

Steps 1 to 6 relate to reducing chemical N fertiliser use and a change in chemical N fertiliser type to NBPT-Urea (Protected Urea). These are two of the key factors influencing GHG emissions.  Nitrogen fertiliser use on the Signpost cattle farms has decreased by 22% since commencing the programme in 2021.  This was achieved by:

• Optimising soil fertility: On Signpost cattle farms, 25% of all soils sampled were optimum for pH, phosphorus (P) and potassium (K). This compares with a national average of 13%.
• Applying lime to correct low soil pH, which will release N from the soil: the Signpost farms were extensively soil sampled in late 2021 and early 2022. The farmers have used the results to target lime applications during both 2022 and 2023. On average in 2023, 33.8 tonnes of lime was spread per farm, equivalent to 0.58 tonnes per hectare farmed.
• Better use of slurry: the adoption of low emission slurry spreading (LESS) on Signpost farms has been significant. In 2023, over 80% of the slurry produced was spread using LESS.  Furthermore, 58% of all slurry was spread during the spring, optimising its N value. 
• Using clover: Signpost cattle farms will be ‘clover-scored’ in 2024; however, evidence from farm visits and discussions with the farmers indicates an increase in white clover, red clover and multi-species swards on these farms.
• Almost half of the fertiliser N applied on Signpost cattle farms was applied as NBPT-Urea (protected urea), a substantial increase compared to just 14% in 2021. The national average for beef farmers in 2022 was 4% (National Farm Survey Sustainability Report 2022).

Table 2. Adoption of the “12 Steps to Reduce Gaseous Emissions” on Signpost cattle farms over three years

Steps 6-10

Steps 6 to 10 focus on increased efficiency, output and reduced age at finishing.  Signpost cattle farms have a relatively long grazing season. Cattle were at grass for 229 days in 2023, despite the difficult grazing conditions experienced on many farms.  Replacement Index for suckler cows increased by €12 since 2021 - the target is an increase of €5 per year. Eighty-two percent of the heifers calved at 22 to 26 months in 2023, up from 71% in 2021. The aforementioned difficult grazing conditions in 2023 had an adverse effect on animal growth performance at pasture, which may have contributed to an increase in age at finishing. The average age at finishing over the 3 years of the project was 16.9, 22.5 and 23.9 months for bulls, heifers and steers, respectively. The building blocks of improved animal breeding, grassland management and herd health management are all being implemented to allow further progress in this area.

Steps 11-12

Step 11 refers to the better management of existing hedgerows and planting of trees on Signpost cattle farms with benefits to biodiversity accruing on these farms as well as increasing carbon sequestration potential.  Step 12 refers to looking after the health of our soils, which includes actions such as, avoiding soil compaction, use of clover/multi-species swards, extended grazing, improving hedgerows and planting trees/hedgerows.

Gaseous emissions on Signpost cattle farms

Total GHG emissions for the Signpost cattle farms is 365 tonnes CO₂ equivalents (CO₂-eq) per farm, corresponding to an emissions per ha of 6.1 tonnes CO₂-eq.  The national average for cattle farms was 4.4 tonnes CO₂-eq per ha in 2022 (NFS Sustainability Report 2022); however these farms have a comparatively lower stocking rate.  Total emissions on the Signpost cattle farms decreased by 2% since the start of the programme in 2021.  The key drivers of the change in emissions on the Signpost cattle farms are:

Chemical N fertiliser use

There was a change in the total quantity of N fertiliser applied and in the ‘composition’ of fertilisers used (Table 3). Total fertiliser N use decreased by 22% from 2021 to 2023.  In 2021, 69% of the chemical N was applied as calcium ammonium nitrate (CAN) and associated compounds, with this reducing to just 34% in 2023.  A reduction in CAN and chemical N in compounds contributes to a reduction in GHG emissions. The quantity of straight urea used in 2023 decreased by 7 percentage units, compared to 2022. Although this decrease in urea application has minimal impact on GHG emissions, it does further decrease ammonia emissions.  The quantity of NBPT-Urea (protected urea) used more than tripled between 2021 and 2023, corresponding to 47% of total chemical N applied as NBPT-Urea (protected urea) in 2023. An increase in NBPT-Urea (protected urea) is positive in terms of reducing both GHG and ammonia emissions.

Table 3. The percentage of chemical nitrogen (N) fertilisers used on Signpost cattle farms in 2021, 2022 and 2023

Lime use

Average lime usage increased from 29.6 to 33.8 tonnes per farm between 2021 and 2023.  Despite an initial increase in GHG emissions associated with the application of lime, this increase in lime use is positive, as optimum soil pH will ultimately permit lower N fertiliser application rates and increased N and P use efficiency.

Change in livestock numbers

There was a slight decrease in livestock numbers (2.9%) on the Signpost cattle farms from 2021 to 2023.  Livestock numbers contribute to over 70% of the total emissions associated with cattle farming; therefore, any change in livestock numbers, however small, can contribute to a change in GHG emissions.    

Conclusion

Considerable progress has been made on the Signpost cattle farms to implement the technologies for reducing GHG and ammonia emissions.  There is still potential to reduce total GHG emissions on the Signpost farms.  This can be achieved by further reducing chemical N use, and increasing the proportion of chemical N applied as protected urea. Other areas for improvement include reducing cattle age at finishing and reducing heifer age at first-calving.  The Signpost farms show what is possible in terms of the use of climate mitigation technologies, and Teagasc believes that they can point the way forward for all farmers.