The following is a recent short paper that John Corbett produced for the Farm Efficiency Committee of the ITBA, which he kindly chairs. John is better known as the grassland and nutrition specialist at Coolmore Stud. Whilst focused on Ireland, much of the paper’s content applies to all stud farms.

The Irish equine industry understands its duty to protect the natural environment through conservation and farming in a sustainable way. It is essential to continue to reduce the environmental  footprint by employing best farm practice to maintain and improve climate, water and air quality, biodiversity, ecosystems and soil fertility.

Climate

Agricultural carbon sources

Due to the lack of heavy industry, agriculture is responsible for 33% of Ireland’s greenhouse gas (GHG) emissions. In most European countries agriculture produces approximately 10% of the total GHG emissions.

Methane is responsible for 64% of total agricultural emissions in Ireland. Enteric fermentation leading to cattle belching, releasing methane, accounts for 90% of this. The remaining 10% is from the storage and management of animal manures.

Nitrous oxide is responsible for 35% of total agricultural emissions. These are associated with the application of nitrogen-based fertilizers and animal slurries to agricultural soils.
The release of GHG from tillage farming is small compared to the livestock sector and has been reduced further by growing cover crops, incorporating straw and reducing ploughing.

Ammonia is an air pollutant that can indirectly lead to nitrous oxide production. As a principal loss pathway for agricultural nitrogen, ammonia emission reduction is crucial in improving farm  efficiency and sustainability. Animal manures produce around 90% of ammonia emissions in agriculture. Chemical fertilizers and road transport combined account for the remaining 10%.

Agricultural carbon sinks
Carbon dioxide is removed from the atmosphere by trees, hedges, plants and crops through photosynthesis and stored as carbon in biomass in tree trunks, branches, foliage, roots and soils.  Woodlands and permanent pastures are referred to as carbon sinks because they can store large amounts of carbon in their vegetation and root systems for long periods of time, a process known as sequestration.

 

Carbon footprint

On-farm GHG production studies have identified animal emissions from enteric fermentation, manure storage and handling (84%) as the largest contributor to farm GHG emissions. This is  followed by chemical fertilizer use (13%), diesel (2%), nitrate leachate (0.5%) and electricity (0.2%).

If the industry can make small changes in the way farmyard manures are used and by managing our chemical fertilizer inputs as efficiently as possible and employing best farm practice for sustainable agriculture, a positive environmental impact can be achieved.

The key areas are how we manage our natural resources, which are clean water, fresh air, healthy fertile soils, biodiversity and vibrant ecosystems.

Clean water

Nutrient pollution (caused by too much nitrogen and phosphorous in waterways) is the key environmental issue impacting on the state of Irish surface waters.

Nutrients, such as phosphate and nitrate, are responsible for eutrophication which is the enrichment of water leading to an increase in the growth of algae and aquatic plants, depleting fish numbers and leading to a general deterioration in water quality.

  1. Respect and protect buffer zones when spreading fertilizer and spraying.
  2. Protect from run-off and leaching by planting hedges as a line of defense.
  3. Hedgerows and woodland act as buffers, intercepting overland flow, retaining sediment. and phosphorous, thereby improving water quality and reducing flood risk.
  4. Apply fertilizers at the optimum time for plant growth.
  5. Test water quality regularly.

Fresh air (ammonia and GHG emissions)
Ammonia and GHG emissions by producing food more efficiently with fewer inputs

  1. Extensive grazing. Low stocking rates (75 kg/Ha). Lightly stocked farms have a lower negative environmental impact than heavily stocked farms.
  2. Extend grazing season.
  3. Addition of aerobic microbes/bacteria to manures to stabilize nitrogen volatility and speed up composting process.
  4. Limit manure/slurry storage times by processing (compost) and recycling onto land.
  5. Use Low Emission Slurry Spreading (LESS). Trailing shoe.
  6. Harvest lab. Measures the amount of nutrients applied.
  7. Keep chemical fertilizer use to a minimum.
  8. Variable rate fertilize application. GPS for accuracy.

 

Soil fertility

Increased focus on environmental sustainability on farms will lead to accurate monitoring requirements for balancing soil fertility and crop nutrition with lime fertilizers, and organic manure recycling.

  1. Soil analysis. Grassland, 4 Ha every four years.
  2. Nutrient management planning.
  3. Improve soil organic matter content.
  4. Increase soil microbial communities and populations.
  5. Lime according to soil results.
  6. Target low fertile soils with organic fertilizers.

 

Biodiversity and ecosystems

Biodiversity refers to the variety of plants, animals, and microorganisms above and below the soil that interact within an ecosystem.

  1. Stud farms have a good diversity of habitats such as field boundaries, hedges, streams, native woodland, trees, and species rich pastures.
  2. 90% of grassland fields are below 5 Ha in size.
  3. Hedgerows are an important feature of stud farm landscape. They provide a multitude of ecosystem services and sequester carbon in both above and below ground biomass. They give stud
    farms their distinctive character and field pattern.
  4. Hedgerows and woodland act as buffers, intercepting overland flow, retaining sediment and phosphorous, thereby improving water quality and reducing flood risk. Stud farms can protect the watercourses further from nutrient runoff by planting hedges along the water buffer zones.
  5. Having a yearly plan to plant a small line of native hedgerows will have a significant effect on biodiversity and above/below ground woody biomass over time.

There is ample room for both agriculture and biodiversity to develop side by side if effectively managed space is left for nature. Irish stud farms can be a good example of this.

 

Renewable energy

In addition, emphasis should be placed on researching renewable energy production to dilute fossil fuel use in the future.

  1. Willow plantation.
  2. Anaerobic digestion, solar and wind energy.
  3. Water harvesting.

Conclusion

Each farm and farmer is unique. Policy makers must develop a better understanding of farming decisions and behaviour if policy is to be effective and to encourage the adoption of practices that will improve environmental stewardship.