Why grow spring oilseed rape?
For many farmers, spring oilseed rape is generally grown by default after the failure of
an autumn sown crop, however more and more farmers are beginning to choose spring rape as part of a
well considered crop rotation.
Spring crops allow flexibility in the rotation if preceding a late harvest, which is followed
by poor weather conditions, and in general allows growers an excellent opportunity to sort out
pernicious weed problems, such as black grass, while fields lie fallow through the winter. There
are also benefits from the ELS scheme, where farmers can receive 120 points by planting a crop
after mid February into over wintered stubble. The aim of this is to help preserve the population
of farmland birds.
While peas and beans offer advantages in terms of ‘free’ nitrogen, they are often difficult to
fit in a rotation, and can be very poor in a bad harvest year. There is little interest in barley
at present, and spring sown wheat does not allow a cereals break, and yields can be very low.
Linseed looks interesting right now, due mostly to problems with GM contamination (several years
ago) being found in imported seed, and this has pushed the value up considerably, however, linseed
is well known to give harvest problems – a very sharp knive is needed on the combine!
Drilling oilseed rape at the end of March/ early April means less pressure is put on both man
and machine. Spring osr only requires 150 days to grow; therefore Phoma isn’t a problem due
to its short vegetative stage and specific temperature requirements. The occurrence of fungal
diseases are much less than in winter rape, so disease control is rarely necessary and with the
exception of flea beetle, spring oilseed rape is generally pest free. With Cruiser OSR now
available on spring OSR, giving increased persistence of the insecticide, even this problem may now
be controlled, so spraying may not be economically justifiable. Even pigeons are less interested in
spring OSR, as it grows so quickly and of course there are other food sources available in the
spring.
The strong root associated with the rape enables deep penetration and more soil fracturing
than cereals. Spring rape will play an integral part in the future of farming, helping to meet new
environmental and rotational requirements.
Although spring oilseed rape is tends to have lower oil content than winter types, with the
help of relatively high oil varieties such as Ability those all important oil bonuses can easily be
reached.