With oilseed rape fields in full flower, it is easy to forget the lurking legacy of the wet winter, which highlighted differences in cultivations, according to Masstock.
“Conditions during establishment were generally good, and most crops got away nicely and flourished during the mild autumn,” says the firm’s David Langton. “However, subsurface drainage, or lack of it, became apparent in the new year as the rain kept falling.”
The firm’s Best of British Oilseeds initiative has continued to highlight the importance of good subsoil structure so that the nutrient-hungry oilseed rape plant can develop a large root and make best use of the soil’s resources, says Mr Langton.
“Allowing excess winter rainfall easy passage through the soil is also essential because OSR does not like having ‘wet feet’ through the winter.”
That makes it essential to assess the subsoil structure before establishing the crop and, if required, cultivating the soil at depth, he adds.
“Heavy soils are more prone to waterlogging and will often need subsoiling before an OSR crop.”
Cleanacre’s agronomist, Steve Moss of the Masstock Group, saw a good example of this on a Gloucestershire farm where only part of a heavy field was subsoiled.
Other cultivations were the same across the rest of the field – disc and press followed by drilling and rolling.
“Establishment across the whole field was excellent, with the crop going into the winter with a good green area index,” says Mr Moss.
“However, the area that was not subsoiled became clearly visible in the new year after a month of rain.Growth was halted and the crop went backwards, with some root tips rotting off where it was not subsoiled.”
Masstock SMART Farm trials have highlighted the importance of appropriate cultivations for oilseed rape, with average differences of 0.5t/ha where roots did not develop fully, says Mr Langton.
Oilseed rape plants cannot develop properly on waterlogged land as in this Gloucestershire field, which was only partially subsoiled.