Following Oilseed Rape through the season
Oilseed Rape (Brassica napus) is a relatively new crop in this country – I remember when studying agriculture at university in the mid-1980’s my tutor Dr E Evans was a specialist in Oilseed Rape (OSR) as it was a relatively new crop, though that is more years ago than I care to remember! OSR is a member of the Brassicaceae or cabbage family the same as swedes. (Incidentally the swede often confused with or called a turnip – which is from a different cabbage family Brassica campstris, but to add to the confusion there is also a turnip rape plant in this family too!) Oilseed Rape is called Canola in America. OSR is grown mainly for its oil-rich seed, the third largest source of vegetable oil in the world. The remains of the crops after harvest – the straw – can be baled and is used for bedding often with poultry and ducks. OSR is a valuable break crop on many arable farms as it is from a different plant family to cereals. It also has the benefit of being grown and harvested with the same machinery that is used to grow cereals.
Seasonality of Oilseed Rape
Oilseed rape can be planted in the Autumn or Spring and is harvested in the early summer. The harvested crop once dried can be safely stored until needed so in that respect is not really a seasonal crop.
The crop production cycle below is generally that of Autumn sown Oilseed Rape.
Autumn to Early Spring
Preparing field for OSR.
Most OSR is sown in the Autumn as this usually gives a larger yield than spring sown crops. The aim is to do this before the middle of September so that the crop has grown enough to survive the winter. The preparation for this often starts with ploughing to bury the remains of a previous crop.
Watch ‘Ploughing ‘ in video player above
Making a seedbed
As oilseed is very small seed the seedbed must have a very fine tilth so the seeds are covered but not too deep. This often means using power cultivators like the Power Harrow shown and going over the seedbed several times.
Watch ‘seedbed ‘ in video player above
Planting or drilling seed
Once the farmer is happy with the seedbed he will drill or plant the seed with a seed drill. The aim is to get the seed planed before the middle of September so that the oilseed plants are big enough to survive the winter
Watch ‘drilling seed ‘ in video player above
Spring – Summer
Keeping Oilseed Rape Healthy
Just like any living thing plants can get disease and suffer if not given all the nutrients they need. So the farmer must give the OSR fertiliser to provide all the nutrients it needs. He must also sometimes spray the crop to protect it from diseases and pests like pollen beetle, but without killing bees which are needed to pollinate the plants
Watch ‘Spraying’ in video player above.
Harvesting Oilseed Rape
Once the oilseed plants have finished flowering it starts to form pods with seeds in. Eventually the crop begins to die and turn brown. Once the crop has all died off and the pods and seeds are dry enough the crop will be harvested with a Combine Harvester
Uses of Oilseed Rape
The Oilseeds are crushed to produce an oil which can be used as extra virgin oil for cooking. The oil is also used in many other products – it will usually be labelled as vegetable oil rather than rape seed oil. The crushed seeds are then used as an ingredient in animal feeds.