25 February 1999
Nitrogen on winter barley
HOW much nitrogen should I be applying to my winter barley now when it hasnt had any at all since sowing?
David Millar, Crops magazine
BARLEY crops are looking yellow at the moment in Scotland. This is
mainly because of waterlogging and manganese deficiency, although lack
of nitrogen is also having an effect.
Crops suffering from manganese
deficiency can also suffer from very cold weather, so growers should
wait for better weather before treating with manganese. Beware frosty
conditions, which will cause severe scorch.
If the yellowing is due to nitrogen deficiency, there are two
One says put on a small interim application (up to 40kg/ha)
because stressed crops lack good root structure and nitrogen will have
leached out of the root zone.
The other argument is for holding off
until a main top dressing because an application now will have little
effect and crops are generally well capable of recovering even when
nitrogen is held back until mid-March.
Much depends on local conditions, particularly with regard to
waterlogging and leaching, and to how sensitive the grower is to
neighbourly jibes about sick crops.