Development and validation of on-farm sampling protocols for collection of marketing (quality) samples at harvest


Cereals & Oilseeds
Project code:
01 July 2003 - 31 December 2003
AHDB Cereals & Oilseeds.
AHDB sector cost:
£19,799 from HGCA (Project No. 2761)
Project leader:
J KNIGHT1 , R WILKIN2 and J RIVETT1 1 Department of Environmental Science and Technology, Renewable Resources Assessment Group, Imperial College London, Silwood Park Campus, Ascot, Berkshire SL5 7PY 2 Universal Cereal Services, 39 Denham Lane, Chalfont St Peter, Gerrards Cross, Buckinghamshire SL9 0EP



About this project


The aim of this project was to develop a limited set of protocols for sampling grain to measure quality characteristics. The protocols were tested to establish the variance attached to each quality measurement to enable users to understand the probability of a sample proving to represent a grain lot for parameters measured.

Protocols laying out sampling instructions for grain coming into store directly and after cleaning or high temperature drying were developed in conjunction with input from an expert panel drawn from the grain industry both in the UK and overseas.

Testing of protocols took place during the 2002 harvest at 16 farms from Kent to Aberdeenshire to try to incorporate geographic variability and differing conditions. Samples were taken to assess the variation between and within trailers (using spear sampling, pelican samplers and scoop sampling) and the impacts of cleaning and drying on sample quality. The performance of composite samples versus a series of single samples was also examined.

Results indicated significant variation between trailers but statistically insignificant variation within trailers. There were no major differences between the sampling methods although spear sampling tended to result in increased specific weight. Composite samples were adequate for quality analysis with little difference between the single and composite sample results.

Drying and cleaning resulted in reduced moisture content and fine material. However, the associated handling tended to increase specific weight and some other characteristics underwent significant change. Samples for quality assessment should therefore be taken after, rather than before, drying.

Grain is inherently variable as it comes off the field and requires careful sampling. However, single samples from each trailer provide a practical method that gives an acceptable indication of grain quality.