Cultural weed control in cereal crops - first report

11 June 2013

The group met on Tuesday 11 June 2013, kindly hosted by John Pawsey at Shimpling Park Farm, Shimpling, Suffolk. Nine people attended in total including four farmers, one carer/partner, two researchers, one sponsor's representative and one organic grain trader.

Structure of the meeting

  • Introduction to Shimpling Park Farm – John Pawsey
  • Overview of Field Labs – Martin Todman
  • Farm walk, review the issues – John Pawsey, with participants
  • Group discussion, trial plan – Martin Todman, with participants
  • Summary & close – Martin Todman


Shimpling Park Farm follows a stockless organic rotation on mainly Hanslope series soils. Rotation has been developed to grow for the market, based on red clover ley > w wheat > w barley > w beans > w wheat or winter barley (undersown).

This management regime has led to a build up of weeds (blackgrass, charlock, wild oats), despite tools such as weed surfer and inter-row hoe.

John Pawsey is adapting his management to include cultural controls. Apparent differences in field crop competitiveness were observed on the farm walk, looking at fields of winter wheat, spelt wheat, winter barley, spring oats.

Group discussion focused mainly on blackgrass due to the fields seen and the time of year. The discussion opened up to include participants own farm experiences and the role of overwintered green manures. The topic of allelopathy was raised, particularly the possible benefits of rye straw. Further discussion has continued via email on this topic after the meeting.

Trial plan

The on farm trial plan is to select one field at high blackgrass risk (probably the cereal crop after beans). In that field John will sow an 8m strip of every cereal crop to be grown on the farm for harvest 2014. These crops are not yet finalised but likely options are:

  • Winter wheat
  • Winter barley
  • Winter oats
  • Spelt wheat
  • Winter triticale
  • Spring oats
  • Spring barley

Assessments of weed levels are to be made by participants at the planned meetings through the course of next season.

Future meetings

Three further meetings are planned for:

  • Autumn - after winter crop establishment
  • Spring - after spring crop establishment
  • Early summer - for final assessment

Specific dates have not yet been finalised. Additional participants will be welcomed. If you wish to attend, please contact us on or 0117 914 2400.


Field lab - Soil analysis – its use and interpretation
16 March

Tolhurst Organic Partnership C.I.C., West Lodge, Hardwick, Whitchurch on Thames, Pangbourne RG8 7RA

Field Lab: Cultural methods to control black grass
24 March

Shimpling Park Farm, Shimpling, Bury St Edmunds, Suffolk, IP29 4HY

Supported by...

Duchy logo

Prince of Wales's Charitable Foundation

Organic Research Centre