You can't manage what you don't measure and as we try to farm more efficiently, reduce artificial fertiliser use and improve soil indices, it is essential to know the nutrients going out on the farm.
Nutrient content of slurry is something that can vary hugely between systems and animals.
Testing can play a valuable role in taking out some of the unknowns.
While there are guidelines available for nitrogen (N), phosphorus (P) and potassium (K) contents in slurry, there can be huge variation across different systems, farms and animals' diets.
Sampling on Tullamore Farm
We recently took slurry samples on Tullamore Farm to take out some of the unknowns and will use the results as part of the nutrient management plan this season on the farm.
The samples were taken from under the cows and from under the finishing bulls.
With the bulls being fed a finishing ration along with silage, it would be expected that P would be higher in this sample, but the results will tell all.
The results will return dry matter percentage, N, P and K levels.
Sample results will vary between labs and farmers should ask the lab to translate results to units/1,000 gallons where possible.
Total N is likely to be measured and the availability is then somewhere around 40% to 50%.
P and K availability will differ with soil index. It is important to discuss the results of your slurry test with an adviser and use appropriately.
We will share the results from Tullamore Farm shortly.
In the meantime, it might be an idea to get your own slurry tested, but take caution when sampling and have someone with you while taking the sample.
Only open the extraction point enough to get a sample. It does not need to be fully open.
Approximately 2l of slurry are needed, so a handy thing to do is remember to keep the lid of a mineral bucket so a slurry sample can be taken with the bucket and sealed for ease of storage and transport.
Just make sure that the mineral bucket is clean before taking the sample.
Slurry testing can vary in price, so shop around before you sample.