Soils samples, can you afford not to take them?
Kevin O’Hara, Drystock Advisor, highlights the importance of soil sampling and nutrient management plans for farmers to comply with fertiliser regulations.
A question I often ask farmers nowadays when they visit my office is: ‘Have you taken soil samples?’ In many cases, the response I receive is: ‘No, I don’t need any.’ However, this is no longer the case for most farmers, even for low-stocked farms that only buy small amounts of fertiliser and feed each year.
I see problems repeatedly where a farmer has received either a conditionality (cross compliance) inspection or ACRES inspection. For these inspections all fertiliser used in the year previous and meal fed in the year before that, is required to allow DAFM to calculate what chemical fertilizer allowances each individual has.
Common Issues with Phosphorus Allowances
In a drystock situation, a typical issue is the Phosphorous (P) allowance. Many lowly stocked drystock holdings (<85kgs organic N/ha) have a smaller allowance for P than they think. In a situation where a farmer has no soil samples, his or her farm is all assumed to be soil index 3 for P. This means the maximum allowance of P per hectare is 7kgs (this includes P in bought-in concentrates, P in imported slurries and chemical P in the form of bagged fertiliser).
The problems typically arise in situations where a farmer is using what they deem to be small quantities of products such as 18/6/12 or 10/10/20 as they have always done. A 50kg bag of either product contains 3kg and 5kg of P respectively, and when spread at a low volume of 1 bag to the acre or 2.5 bags/ha you soon see where the issues arise.
To further exacerbate the problem, all bought in concentrates contain P. Each tonne of meal has 5kgs of P, so farmers who may be finishing cattle or feeding high levels of concentrates to weanlings or lambs may have little to no P allowance. Many of these farmers do not intentionally break the rules but are unaware of the legislation which is in place and can end up with substantial penalties, especially where ACRES contracts are involved.
Nitrogen Allowances on Intensive Farms
On more intensive farms P is still an issue, but so is the chemical Nitrogen (N) allowance, which is based on your previous years stocking rate and can vary greatly depending on overall farm stocking rate. As this is changing yearly you cannot assume you can use the same amount this year as in a previous year so this is something that needs to be monitored yearly.
Take Soil Samples to Protect Your Farm
To safeguard your farm and avoid these pitfalls, the first step is to take soil samples. Here’s how to do it effectively:
- Sample area: 2–4 hectares
- Depth: Top 10 cm of soil
- Number of cores: Approximately 20 per sample
- Tools: Use a suitable soil corer
- Timing: Wait 3–6 months after P & K applications
- Lime applications: Leave a two-year gap after applying lime
Like everything these samples come at a cost but that cost could save thousands in penalties and in fertiliser savings.
What Next?
After taking the soil samples and getting the results, it is impossible for any advisor or sales representative to give accurate fertiliser advice to a farmer without a nutrient management plan (NMP). Farmers previously enrolled in GLAS may have created an NMP, but these plans are likely outdated and need revision.
These NMPs account for all concentrates fed, the soil sample results, the farm stocking rate, if there is any peat soils on the farm (which have reduced P allowances) and any reseeding which was completed on the farm. Without these NMPs advisors will be shooting in the dark when it comes to fertiliser advice.
And remember, as of September 2023 all fertiliser purchased and used in the calendar year by a farmer must be recorded on a National Fertiliser Database, which is controlled by DAFM.
I hope farmers now realise the value and the safeguards a few small boxes of soil can provide to their farming business. For further queries, consult your local advisor.