Practical actions for efficient and environmentally sustainable farms

Owen Fenton and Bridget Lynch discuss integrating technologies into farming systems to improve soil health, carbon sequestration, biodiversity, emissions reduction, and water quality, encouraging farmers to adopt one new technology each season.

Integration of actions into farming systems

The aim of the Johnstown Castle Open Day was to make our research and technologies farm ready with scientific rigor leading the way. Our proposal to you is: implement one additional technology on your farm (or with your customers) in each farming season over the next 12 months.

We acknowledge that it has been an extremely testing 12 months on Irish farms with all farm enterprises negotiating difficult weather conditions from harvest 2023 through to early summer 2024. However, as an industry our environmental reduction targets remain. It is acknowledged that farmers are weary and that, the ask to do more for the future of our agricultural industry by adopting more and perhaps new technologies on farm may seem overwhelming and a challenge for next year.

Table 1 maps out scientifically proven effective technologies as they apply in the farming system and season. When stacked, the accumulative benefit of multiple technologies will move the dial for the improvement of soil health and fertility, enhancement of farmland biodiversity, reduction in agricultural gaseous emission and improved quality of waterbodies. Indeed, many of the technologies and underlying principles are cross-cutting with benefits for two or more pillars for each action, and can also have positive benefits for farm efficiency/profitability.

Table 1. Mitigation targets and application to farming system and season.

Actions to enhance soil health, carbon sequestration and fertility

Soil health

Our soils are precious resources that underpin sustainable food production and many other important ecosystem services for society. Our soils support the production of food, feed and fibre. There are many other functions supported by soil including, the re-cycling of nutrients, sequestration of carbon & regulation of our climate, purification and storage of water. Soils are also an important habitat for biodiversity, containing nearly 60% of all life on the planet. In Ireland our grass-based animal production and high yielding arable cropping systems rely heavily on the availability of healthy soils to deliver high quality, profitable and sustainable food production on farms. The traditional view of high quality soil, measured by the soils performance for crop production alone, is now considered inadequate, as it does not consider the wider impact that soils have in the environment and for society. A decline in soil structural quality which leads to soil degradation and compaction is often the consequence of more intensive management practices. This can also lead to reduced capacity for water to infiltrate and drain through the soil, to store water and to purify water in the landscape. Chemical indicators in soils provide much information in relation to nutrient cycling, primary production and carbon sequestration functions in soils. In particular soil pH and soil organic matter are key factors, which regulate nutrient availability in soils and the delivery of different soil functions including carbon sequestration and macro/micro nutrient cycling. Soil biology is the “engine of the soil” and soil biodiversity and the soil microbiome is at the centre of soil functioning. Biological indicators provide valuable information on the effects of past and current management on soil health. For example, the abundance and presence of earthworms is a useful and easily identifiable soil health indicator. However, much of the soil biology cannot be seen with the naked eye and requires more sophisticated analysis, which may not always be practical for routine in-field soil health assessments. However, much can be inferred about biological health of the soil by visually examining the soil habitat. Strategies to avoid soil compaction in grassland include maintaining soil organic matter, keeping a living root in the soil, avoiding trafficking wet soils with heavy machinery and high stocking rates. Soil structure is weaker when wet and prone to damage. In grasslands, pugging and poaching from livestock treading, as well as machinery rutting, will occur if soils are wet, and must be avoided. When driving machinery across soil, stick to tramlines or straight passes and avoid trafficking the entire field, even in dry conditions. Controlled traffic farming, which uses GPS technology is designed to ensure machinery uses defined and permanent paths. Also traffic during appropriate soil moisture conditions, reduce number of passes and manage headlands. Try also to reduce axle loads by using trailers with multiple axles. Lowering tyre pressures (to safe levels, use larger tyres, VF/IF tyres and more wheels are options) helps to spread weight over greater surface areas and can greatly reduce the risk of soil compaction. Tracks, wide tyres or duel wheels work on the same principle and can also be beneficial.

Soil carbon sequestration

Soil carbon sequestration is an important mechanism that removes carbon dioxide from the air and stores it in the soil. Strategies for carbon sequestration include avoiding soil compaction, increasing the proportion of grazing on the farm, improving existing hedgerows, improving soil fertility, establishing clover and multi-species swards, planting extra hedgerows and additional woodlands/forests and restoring a wetland. On tillage farms strategies include improving soil fertility, including organic manures applied to crops, and during non-cropping times introducing cover crops and incorporating straw. There are a number of factors that influence the rate of carbon sequestration in agricultural ecosystems including: climate; soil type and land-use.

Soil fertility

Good productive soils are the foundation of any successful farming system and key for growing sufficient high quality grass to feed the herd. Therefore, the management of soil fertility levels should be a primary objective of every farm where maintained or enhanced production is an aim. To measure soil fertility we test soil to identify the pH level, phosphorus (P) level, and potassium (K) level. A recent review of soils tested at Teagasc indicates that the majority of soils in Ireland are below the target levels for pH (pH 6.3), P and K (i.e. Index 3) and will be very responsive to application of lime to increase pH, and also P & K. On many farms sub-optimal soil fertility is leading to a drop in output and income if allowed to continue.

Five steps to soil fertility management are:

1. Take soil samples for the whole farm and repeat over time (3 to 5 years).
2. Lime should be applied to neutralise soil acidity and raise the soil pH to the target soil pH for the crop been For mineral soils, a soil pH 6.3 is recommended for grassland. The soil pH should be higher (Barley/Beet) for tillage crops and aim to maintain at pH 6.5 to 6.8. Apply lime as a priority in line with the lime advice as per the soil test report.
3. Target Index 3 - aim to have optimum soil P and K (Index 3) fertility levels in all fields.
4. Use slurry/farmyard manure on the farm as efficiently as possible, and top up with fertiliser as required. Implement the 5R principles of right rate, right type, right application method (e.g. LESS), right timing and right place. Aim to apply slurry and manures to fields that have high P and K requirements (e.g. grass/maize silage). Apply in spring time under cool and moist weather conditions to maximise N recovery.
5. Have a balanced nutrient supply.

Clover (white and red) offers an alternative to expensive artificial fertilizers and helps towards environmental sustainability. Incorporating clover in grassland swards has the potential to reduce costs, improve profitability, reduce greenhouse gas emissions and enhance soil biodiversity, and should also be considered within a nutrient management plan.

Teagasc provides tools to aid with Nutrient Management Planning (NMP) and grass production and utilisation. NMP Online is an online tool that allows agri-professionals to produce high quality nutrient management plans for farmers by combining their expert knowledge of soil fertility with a range of information sources. The key benefits of NMP Online are that it helps to efficiently complete complex nutrient calculations, enables you to access latest aerial imagery and mapping, create user friendly reports and maps and training and ongoing updates for available for all users. PastureBase Ireland is another tool to help Irish dairy, beef, and sheep farmers manage their grass production and utilisation. Additional features are continuously being added to improve the user experience and the quality of the information available to the farmer user. Recently, nutrient use efficiency (NUE) calculator and mapping functionality for a farm have been added to PastureBase. In addition, AgNav is a new sustainability toolkit being jointly developed by Teagasc, ICBF and Bord Bia - with the support of the Department of Agriculture - that provides farmers with accurate and verifiable data to support decision making on farm to help meet agriculture’s Climate Action.

Biodiversity: actions to maintain, enhance, diversify, and connect existing habitats and create new habitats.

Biodiversity provides us with clean air, fresh water, healthy soil, fuel, fibres and the food we eat. It can help us to mitigate against and adapt to climate change. Despite the many benefits of biodiversity, it continues to decline and biodiversity loss has far-reaching consequences for future generations. Farmland has the capacity to make a big difference in halting biodiversity loss. The key message to communicate in relation to managing farmland biodiversity is to, maintain first, enhance second and create if not already in existence.

Protecting farmland biodiversity, while maintaining a productive farm business is achievable by following these key steps:

1. Identify what habitats are already present
2. Maintain, enhance, diversify and connect existing habitats
3. Where there are few existing habitats, create new habitats

Every farm has some value for biodiversity, but some farms offer more value than others. One way to enhance biodiversity on your farm is to manage hedgerows less intensively. Maintaining a diversity of habitats is important, as different habitats support different species. Different pollinators have different traits, thus supporting a higher species richness (diversity) of pollinators can contribute to increased pollination and increased pest control, which increases crop seed yield and economic value. Habitats in poor condition can be enhanced through sensitive management. If invasive alien species are present, aim to remove them because they displace native species. Noxious weeds such as docks, ragwort and thistle can be kept under control by mechanical means or by spot treatment. Linear farmland features such as hedgerows, field margins and watercourses, managed appropriately can act as corridors for nature through the landscape, allowing farming and biodiversity to co-exist. Maintaining and managing existing old hedgerows with high levels of associated fungi, lichen, moss and invertebrates is far more beneficial than planting new hedges. No matter which biodiversity-friendly areas are on the farm, it is vital that evidence-based actions are used to manage these, to protect and enhance farmland biodiversity. It is imperative that new habitats such as planting trees or incorporating a pond, are located in the right part of the farm and that they do not replace existing habitats.

Six actions farmers can take that will allow biodiversity to coexist within a productive farming system are:

1. Create nesting sites for solitary mining bees
2. Create nesting sites for cavity nesting bees
3. Plant native trees
4. Avoid the use of herbicides and fertiliser under hedges
5. Allow hedgerows and margins to flower and fruit
6. Identify and protect species rich grassland

Actions to reduce gaseous emissions

Three main greenhouse gases (GHGs) carbon dioxide, methane and nitrous oxide, and the two main GHGs for agriculture are methane and nitrous oxide. Nitrous oxide (N₂O) from nitrogen fertiliser, manures and urine accounts for c. 30% of agricultural emissions. The remaining 70% comes from slurry management and directly from the animals. Agricultural soils are a source of emission in the land use and forestry part of the inventory. Carbon sequestered in our mineral soils is four times lower than the carbon lost from agricultural peat soils. The strategies proposed to reduce emission on your farm include optimising soil fertility, which releases c.70kg N/ha from the soil and reduces fertiliser requirements. Soil fertility is important for clover/multi- species sward establishment and the opportunity to dramatically reduce nitrogen fertiliser use. Use of low emission slurry spreading (LESS) increases the nitrogen supply in slurry, reducing fertiliser requirements. Where chemical N is used then replacing CAN and urea with protected urea can reduce emissions by over 70%. Ammonia is not a greenhouse gas, but it can indirectly contribute to greenhouse gas emissions. Ammonia comes mainly from management of animal manures (housing, slurry storage and land-spreading) but also from grazing animals, and finally from spreading of synthetic fertiliser. Teagasc has carried out extensive research on technologies to reduce these emissions such as: protected urea, low emission slurry spreading (LESS), clover, extended duration grazing, slurry additives and others.

Better Farming for Water – 8 Actions for change

Abundant, clean and good quality water is a fundamental cornerstone of any thriving society and is necessary for a vibrant economy and enjoyable living environment. Read more about Better farming for water - 8 Actions for Change.

All farmers can play a role in protecting and improving water quality, by focusing on three critical management areas:

1. Nutrient management
2. Farmyard management
3. Land management

In terms of nutrient management: Reduce purchased N and P surplus per hectare; Ensure soil fertility is optimal for lime, P and K and only apply fertiliser and organic manure at appropriate time and conditions. In terms of farmyard management have sufficient slurry and soiled water storage capacity and manage and minimise nutrient losses from farmyards and roadways. In terms of land management fence off watercourses to prevent bovine access; target use of mitigation actions such as riparian margins, buffer strips and sediment traps to mitigate nutrient and sediment loss to water and maintain over-winter green cover to reduce nitrate leaching from tillage soils.

Conclusions

There are many actions for efficient and environmentally friendly farms spread across soil health, soil fertility, soil carbon sequestration, biodiversity, gaseous emissions and water quality. All of the actions mentioned are scientifically robust, which should give farmers the confidence for adoption out on farms. Our proposal to you is to select one additional technology to adopt on your farm (or with your customers) in each farming season to apply in the next 12 months. When stacked, the accumulative benefit of adoption on farm of multiple technologies will ensure we move the dial for the improvement of soil health and fertility, enhancement of farmland biodiversity, reduction in agricultural gaseous emission and water bodies. Indeed, many of the targets and underlying principles are cross-cutting with benefits for two or more pillars for action.

Read more from; Farming for a Better Future - Johnstown Castle 2024