Make Lime a priority in 2025

Lime is the key to unlock and increase the efficiency of the main sources of nitrogen (N) – Soil N, Organic N (Cattle slurry / FYM) and Chemical N (fertiliser).  Nitrogen is a key driver of our productive agricultural systems and with a growing world population the demand for food is now greater than ever before and will increase in the next 25 years. 

Improving nitrogen use efficiency (NUE) can help to optimise the use of nutrients on the farm, maintain and improve soil health, reduce excessive N build-up (surpluses) and lessen potential losses of N to the environment. Improving NUE is a key sustainable farming practice and plays a significant role in mitigating the impacts of climate change.

Increasing Soil N Supply

Correcting soil pH to the optimum level for the specific crop is the starting point for improving the supply of soil N.  High levels of soil acidity will impede soil N supply from soil organic matter, and  increasing the soil pH has the potential to increase N supply by up to 30 kg N/ha/year on a drystock farm and 70 kg N/ha/year on a dairy farm. Target pH 6.3 to 6.5 for grass and pH 6.5 to 6.8 grass-clover swards on mineral soil types. This offers a financial savings in fertiliser N bills from €35 to 80/ha/yr.  It is very important to adjust N application rates to account of increased soil N supply when soil pH has been optimised.

Lime and reducing GHG emissions

Research from Teagasc, Johnstown Castle shows that maintaining higher soil pH levels reduces nitrous oxide (N₂O) emissions by up to 39%.  Nitrous oxide is one of the most powerful and destructive greenhouse gases (GHG’s).  Lime is the regulator of soil pH level which has a large effect on the biological processes responsible for the release of nitrous oxide from our soils. 

Take Action Now

Now is the ideal time of the year to check soil test results, identity total farm lime requirements, prepare a liming plan and put a budget in place for lime in the months ahead. 

Rules of thumb & Lime

1. Only apply lime based on a recent soil test report
2. Leave 7 days between applying urea / slurry and lime (no interval for Protected Urea)
3. Leave 3 months between liming and cutting grass silage
4. Don’t exceed 7.5ton/ha in a single application
5. For reseeds / tillage crops work lime into the seedbed prior to sowing

Correcting soil pH is the first step to reducing farm carbon emissions thus the carbon footprint of the food that we produce.  Make lime a priority in 2025 while reducing our dependence on imported chemical N.