Sampling grain at outloading
To keep control of your grain quality, best practice is to take and retain a representative sample from each lorry load, before it leaves the farm.
Why take samples at outloading?
Although unlikely to be a condition of a grain contract, taking samples of grain from each load that leaves the farm is a requirement of some assurance schemes.
Modern specialist equipment often pushes tipped grain up the grain face. This mixes grain and results in large bulks (depths of up to 6–8 m). Mixing is compounded during outloading and some quality aspects change during storage.
As a result, analytical results from samples drawn before storage can only be used to indicate marketing potential and the action needed during storage.
Representative samples at outloading provide the best record of what has actually been dispatched.
Check the contract, merchant annual terms or confirmation note for any special terms relating to sampling.
How to sample at outloading
Sampling methods vary, depending on the equipment used. However, always follow standard protocols to maximise sample validity.
For a 30 t lorry-load of grain, take at least 10 incremental samples of 200 g, as the grain is loaded. This provides a 2 kg aggregate sample. Once mixed, the aggregate sample can be the source of the retained representative (e.g. 2 x 1 kg) samples.
Sampling from the loading bucket (best method)
The best method is to take incremental samples from a loading bucket.
Manual bucket sampling
- From a safety perspective, ideally, have two people present
- Scoop incremental samples from each bucket loaded
Automatic bucket sampler
- Automatic samplers are faster and safer than manual sampling
- They extract a small amount of grain from each bucket as the lorry is loaded
- These are mixed in the sampler to form an aggregate sample
- Choose a sampler that can deliver two 1 kg representative samples for each lorry-load
- All the operator has to do is empty the sampler after each lorry has been loaded and bag the samples
AHDB research shows that ‘bucket’ samples agreed well with samples collected from lorries at delivery, when best practice recommendations were followed by both the farmer and the receiver.
Sampling from spout loading
For grain being loaded into a lorry from a conveying system, it is best that grain is sampled at a point close to the loading location, where samples may be drawn safely. In some cases, an 'interrupter' plate can be inserted into conveying tubes.
Sampling from a grain heap
When loading bulk/on-floor stored grain, position grain for the next lorry into a separate heap. This can be sampled with a conventional (preferably, multi-aperture) grain spear.
How to label and store samples
All samples must be labelled with basic information, including:
- Farm name
- Store name/number
- Bin number
- Vehicle registration and trailer number
Store samples in airtight containers (e.g. polythene bags or plastic boxes) in a cool, dry place, safe from rodent attack.
Retain samples until payment has been received for the loads to which the samples relate.