Soils Samples, can you afford not to take them?

Kevin O’Hara, Drystock Advisor, Teagasc Claremorris

A question I ask many farmers nowadays when they call to my office is ‘have you soil samples taken?’ In many cases the answer I receive is ‘No I don’t need any’. Sadly this is no longer the case for most farmers, even for the most lowly stocked farms who typically only buy a small amount of fertiliser and meal 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.

In a drystock situation the typical issue I come across is the Phosphorous (P) allowance. Many of these lowly stocked drystock holdings (<85kgs organic N/ha) have a lot smaller allowance for P than they think. In a situation where a farmer has no soil samples, his/her farm is all assumed to be soil index 3 for P. What does this mean you ask? It means the max 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).

A limit of 7kgs/ha means very little to most farmers, but, when its broken down many soon realise they have exceeded the limits. 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 whatsoever. 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.

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.

So how can you protect your farm from falling into these pitfalls? The first step is to take a set of soil samples for your farm. See below on how best to complete this. Like everything these samples come at a cost but that small cost could save thousands in penalties and also in fertiliser savings.

• Soil sample areas 2 – 4 ha
• Sample top 10 cm of soil
• Take approximately 20 cores
• Use a suitable soil corer
• Wait 3 – 6 months after P & K applications
• Leave a gap of two years after a lime application

So what next? After taking the soil samples and getting the results, it is impossible for any advisor or sales rep to give accurate fertiliser advice to a farmer without a nutrient management plan (NMP). Many farmers who were in GLAS in the past would have created one of these but it would now be outdated.

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 many 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.

Following on from everything above, I hope all farmers now realise the value and the safeguards a few small boxes of soil can provide to their farming business.  

For any further queries consult with your local advisor.