3 June 2009
Why leave over-wintered stubbles?
If you have spring crops in your rotation, then over-wintered stubbles may be the easiest way for you to provide seed food for birds through the winter.
The economic analysis below shows that you can make a profit from switching to a spring crop using Entry Level Stewardship (ELS) payments for over-wintered stubbles, as well as spreading your workload and getting better spring weed control.
Research has shown that birds such as skylarks and yellowhammers have declined most seriously in landscapes where there are no over-wintered stubbles. It is estimated that skylarks would not decline at all if over-wintered stubbles were left on 20% of the area. Stubbles managed under ELS with no pre-harvest glyphosate, are better for birds. The area needed is probably less if ELS stubbles are used.
Stubbles also benefit brown hares and rare arable plants.
What you can do
Leave cereal stubbles uncultivated and unsprayed for as long as possible to provide seed food for birds.
Under ELS, the over-wintered stubble option requires no use of pre-harvest glyphosate and retaining the stubble without cultivations, sprays or fertilisers until 15 February.
Seed food available for birds peaks at the time of crop harvest, but becomes increasingly sparse from then until new seed sources become available in the spring. The later you can leave stubbles, the better, or you can supplement stubbles with wild bird seed mixtures.
Many seed-eating birds forage more successfully in short stubbles, where they can see approaching danger and fly off. However, gamebirds prefer to forage in tall stubbles that also act as cover for them through the winter.
(by Smiths Gore farm management)
The analysis compares a hectare of winter barley and a hectare of over-wintered stubble with ELS payment followed by a spring barley crop.
|Winter malting barley||Stubble and spring malting barley|
|Income from crop||£810||£709|
|Income from ELS||£120|
|Change in gross margin||£64|
W malt barley yield: 6 t / ha
Spr malting barley yield: 5.25 t per ha
Barley value: £135 / t
For further details and help in doing your own calculations, visit the Smiths Gore website.
Chris Dowse, Hall Farm, Lincolnshire
'Stubbles are retained to provide land to support gamebirds and stand guns on shoot days and it fits in well with our farming system on the lighter land. These options are not suitable on the heavier soils on the Humber Bank due to the heavier weed burden here.
'The weeds are not considered to be an agronomic problem as they are easily controlled in the following crop.
'A variable stubble height is deliberately created in the fields by adjusting the cutter on the combine as the taller stubble provides some cover for gamebirds.'