SNHS – Soil sampling update and results

The fourth and final year of soil sampling in the Soil Nutrient Health Scheme (SNHS) is now well underway. This phase focuses on farms in Co. Antrim and includes any remaining farms across Northern Ireland that were not previously registered.

To date, the scheme has achieved significant coverage. Since its launch in 2022, approximately 440,000 fields have been sampled and 22,750 farm businesses have registered, representing around 93% of all farms in NI. Sampling is typically carried out between November and February with results sent to farmers within 4-6 weeks through the post. After receiving results by post, farmers can also access detailed soil sample analyses and runoff risk maps online via their Government Gateway account.

The fourth and final phase of the Soil Nutrient Health Scheme focuses on farms in Co. Antrim and includes any remaining farms across Northern Ireland that were not previously registered.

placeholder image — The fourth and final phase of the Soil Nutrient Health Scheme focuses on farms in Co. Antrim and includes any remaining farms across Northern Ireland that were not previously registered.

The soil reports and online maps contain essential information on soil nutrient status, including soil pH, soil phosphorus, potassium and sulphur levels. Sampling Programme Project Lead, Alex Higgins, identified some of the trends thus far:

“Soil pH averaged 5.8 across Zones 1, 2 and 3 but varied considerably by farm type and intensity. There was a general decrease from east to west which is likely due to higher rainfall and increased leaching potential in western areas. For many farms the average pH sits below the optimum crop levels which would be most effective at maximising nutrient uptake. For intensive grass or silage fields, lime applications are one of the quickest and most cost-effective methods to increase nutrient use efficiency. When applying lime, the best approach is to apply little and often to slowly raise the soil pH, as very large single applications can cause issues with nutrient availability (potassium in particular). If a soil has a high lime requirement we’d recommend splitting it over a few years. Another point to note is where farms might be considering a shift to multi-species swards or clover mixes that it would be worth getting some tailored advice from your advisor regarding the optimum pH, which may be higher to suit that mix”.

Optimising pH will improve the efficiency of plant uptake of nutrients in soils, including phosphorus (P). In large areas of Zone 1, 2 and 3, soil P Indices are above the soil target optimum of Index 2+ for intensively managed grassland, sitting at 26.7 mg/l Olsen P overall (Index 3). In Zone 1 the average soil P is 28.2 mg/l (Index 3), Zone 2 is 24.3 mg/l (Index 2+) and Zone 3 is 28.8 mg/l (Index 3). Farmers are encouraged to carefully consider their P applications to reduce surplus soil P, as this plant available form is also very susceptible to loss to waterways and can lead to issues there through encouraging algal growth.

The connectivity of land to water in NI is very high with around 5 km of watercourses (open drains, streams and rivers) in every square kilometre. The runoff risk maps being produced as part of the project are intended to highlight areas within fields where there is greatest risk of nutrient and soil loss during heavy rainfall events. Farmers are encouraged to look at these areas and see if there are any small steps that can be taken to break the connection between land and water at these times. This can be as simple as raising the ground level slightly where a runoff pathway goes through a hedge, to slow the flow of water temporarily and allow sediment and nutrients to settle out. There may also be funded measures in current, or future, agri-environmental schemes that could be applicable – such as vegetated buffer strips or sediment trapping features.

As each farm is unique it is essential that farmers consider their individual crop requirements and the environmental setting of their fields when planning any changes in nutrient management. Alex Higgins continues: “Participating farmers have access to resources which will help them to understand soil nutrient status and interpret their soil results. We would encourage farmers to avail of their online reports and maps and participate in the CAFRE online or face-to-face training sessions.”

Farmers are encouraged to complete their CAFRE SNHS training promptly to make the most of the Scheme’s benefits and resources. Register now at www.cafre.ac.uk/snhs-training. Taking part in the Scheme and completing the training is planned to be a conditionality for the new Farm Sustainability Payment from January 2026.