Companion crops
Thinking about growing a companion crop with OSR this year?
Here are a few mixtures that might be useful, and the reasons why it might be beneficial for you!
Why:
Companion cropping has several benefits for the oilseed rape crop.
Improving the soil, particularly through improving soil organic matter, and storing nutrients that could be leached or not utilised by the oilseed rape plant. The rooting systems of the companion crops can also be of use, either thorough drainage or holding the soil together
Species such as Fenugreek emit a smell to deter flea beetles. Other species used can mask the rape plants, again deterring the flea beetle from destroying the crop.
Beneficial insects can also be attracted to the companion crop flowers, which will only help with protecting the crop.
Key species information:
TABOR Berseem Clover
Tabor is the only single-cut berseem clover variety available in the UK.
Killed by frost and does not regrow.
Easy to incorporate.
Grows vigorously as a nurse crop and fixes nitrogen.
FENUGREEK
Natural odour to deter flea beetle.
Grow with buckwheat for a double-edged defence.
Rapid growth with good ground cover
Competes well with weeds.
LIFAGO Buckwheat
Smaller seeded and easier to drill with oilseed rape than standard buckwheat.
Grows more vigorously to protect the oilseed rape plant from flea beetle.
Good leaf canopy
Great phosphate scavenger
BINGO Red Vetch
More vigorous and more frost sensitive than common spring vetch
Ideal grown with TABOR berseem clover as nitrogen-fixing nurse crop.
Key points:
Companion crops act as a root pathfinder for the OSR, which typically would be a ‘lazy rooter’.
Using species, that will naturally die in the winter or cold weather, will reduce costs of destroying the crop.
Improving organic matter in the soil and general soil health
Proving competition to weeds
Utilising nutrients stored in the companion crop once they have died off and broken down. Plants such as berseem clover have a low C:N ratio and will break down quicker.
Designed to deter or confuse the flea beetle, to allow the rape crop to establish well – depending on the species used, it can either provide a canopy or a smell to mask the smell of the rape.
Suggest mixes:
The field below of Acacia OSR in Lincolnshire, drilled on 28th August 2020, with Fix and Block drilled just before on the 23rd of August 2020.
10 days and 2 frosts apart, and the Berseem Clover and Fenugreek have been killed.
Photos courtesy of Boston Seeds