Many grain merchants provide an on-farm grain sampling service to their clients in order to gauge the quality and suitability of grain lots. This is extremely important in the case of malting barley where moisture and nitrogen content, germination and screenings all require to be within defined parameters. Ensuring samples are representative is vital to ensure that grains are matched to the correct contracts and destinations with any substandard lots also identified to avoid potential costly rejections.
COVID-19 has seen many restrictions on normal working practices and when combined with the threat of future lockdowns or the potential for staff having to self-isolate, this may result in some merchants offering to collect samples only.
This means that farmers and growers need to supply identifiable samples which provide as accurate a representation of their crops as possible.
There are several ways to achieve this and a brief description of each will be provided.
The most accurate method for sampling harvested grain that will leave the farm in a “natural” or unconditioned is by taking samples from loads as the store is filled as follows-
- Take two 500g from different parts of each trailer load.
- Decant these samples into a clean dry container or bucket.
- When every field / lot is complete the collected samples should be mixed thoroughly to create an aggregate sample.
- Merchant sample bags should be properly labelled and then filled as necessary from different parts of the mixed aggregate sample with excess air expelled and sealed. Retaining a sample can also be beneficial for future reference.
For grain that is run through a drier or cleaner the process is slightly different.
- Take regular 250g samples from around every 10t from the grain outlet or equivalent for every batch.
- These samples should be decanted into a clean dry container or bucket.
- Once each lot has been processed the collected samples should be mixed thoroughly to create the aggregate sample.
- Once again merchant sample bags and any samples for future use should be properly labelled, filled and sealed with air expelled as necessary from different parts of the mixed aggregate sample.
Where grain has been tipped and pushed up or even as part of the ongoing monitoring regime grain can be sampled in the heap. While not as accurate or as convenient as taking samples from each trailer load, sampling can be undertaken as follows.
- Using a 2 metre, sequential opening, multi-gate sampling spear, samples should be evenly drawn from areas equating to around 50 tons or relevant lot.
- The location of each sample should be carefully noted.
- These samples should be used to fill sample bags as described above.
How much grain each sample lot should represent will vary- some sources recommend 50t lots for quality grains and 100t for feed however the sample may relate to individual fields or even part of the farm. It very much depends on the farmers confidence that the sample drawn is truly representative of that lot. Taking samples from each trailer or regularly as it is processed will allow average quality to be assessed however smaller lots can allow changes in quality to be identified. Finding the balance that works in terms of space, practicality and provide suitable accuracy will vary from farm to farm.
Each lot also needs to be identifiable so a simple plan of the sheds and stores should be drawn showing each sample lot so farmers and merchants can cross reference, avoiding confusion and costly mix ups.
Further details about sampling can be found in AHDB's grain sampling guide
Harvest is an extremely busy time with high levels of dust, moving and tipping vehicles and noise present in storage and handling areas. As such Health and Safety procedures should be reviewed and best practices followed – e.g. hi-vis jackets.
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