Steps to improving the sustainability of Irish tillage farms
The recently published Teagasc Farm Sustainability Report shows that tillage farms have the lowest carbon footprint at 2.5 t/ha, compared to other farming enterprises.
Under the tillage Signpost programme a number of farm practices are been implemented to further improve the sustainability of Irish tillage systems. These measures are focused at improving environmental, economic and social sustainability. Greater emphasis now placed on improving nitrogen (N) efficiency, reducing N leaching and improving soil health as follows:
Step 1. Correct soil pH - Maintain optimum soil pH 6.5+ to increase nutrient availability and efficiency. Soil test results for Signpost tillage farms show that 61% of soils have optimum soil pH and the majority of remaining soils require a maintenance application of lime.
Step 2. Balanced Soil Fertility - Maintain optimum levels of major and minor nutrients to maximise N efficiency. The soil fertility target is to achieve 90% of soils with optimum soil fertility (Soil pH >6.5, P & K Index 3). Currently 42% of tillage fields have optimum pH, P & K. Recent research shows compound fertilisers such as 10-10-20 has lower GHG emissions potential.
Step 3. Increase N Efficiency – When applying fertiliser N check soil temperatures / trafficability and weather conditions at time of application to increase uptake and reduce potential losses.
Step 4. Apply optimum rates of N – Apply economic optimum N rates based on the cost of N per kilo and grain value per tonne. Calculate the break-even ratio (BER) this is the number of kilos of grain to pay for 1 kilo of N. For example, in the past the BER for cereals was 6:1, today ~12:1.
Step 5. Split N applications – Splitting N applications can increase N efficiency and reduce N losses.
Step 6. Grow legume crops – Aim to include 15% of legumes in the crop rotation to reduce overall farm N requirements and reduce N up to 30kg N/ha depending on the following cereal crop.
Step 7. Grow Cover Crops – Cover crops have the ability to take up significant amounts of N over the winter period thus reducing N leaching. In addition, over winter cover crops bring many soil health benefits from protecting soils from winter rainfall to capturing and improving soil carbon.
Step 8. Apply Organic Manures – Where available apply organic manures to replace and reduce chemical fertilisers. Organic manure additions add valuable soil organic matter to continuous tillage soils and increase their biological activity.
Step 9. Chop Straw – Chopping straw brings many benefits to soils from improving soil carbon to soil structure. Chopped straw will return significant amounts of potassium (K) for example 50% of total crop K returned in straw at harvest time.
Step 10. Apply Protected Urea – Protected urea is an efficient ammonium based fertiliser and has lower greenhouse gas emissions compared to CAN. Protected urea offers cost savings per kilo of N compared CAN based fertilisers.
Step 11. Apply Sulphur – Sulphur plays an important role in N use efficiency. Recent research shows that applying the optimum rate of S increases N efficiency and reduces N leaching. Aim to apply 15 to 20 kg S/ha to cereal crops to improve N efficiency.
Step 12. Manage Hedgerows – Hedgerows are a valuable habitat for wildlife, biodiversity and carbon storage. Planting trees / hedges a good option to sequester carbon for long-term storage. Prepare a hedgerow management plan to help improve farm biodiversity, carbon capture and storage on tillage farms.
For further information, see link https://www.teagasc.ie/media/website/environment/climate-change/signpost-programme/12-Steps-to-Reduce-Gaseous-Emissions-on-Tillage-Farms.pdf