Ultra-shallow discs have superseded the power harrow as the tool of choice for cover crop seedbeds at Project Lamport. Niall Atkinson, Agrovista arm systems research and development adviser, says:
“When establishing the cover crop the aim was to try to make the black-grass grow in it so we could trap it and destroy it with glyphosate ahead of the spring cereal.
“At the start of the project we used a power harrow to achieve the necessary soil movement. It did a really good job of establishing the cover crop and setting off the black-grass, so we had a really good kill.
“However, it has become evident how much damage power harrowing was doing to soil structure and soil biology.”
A Vaderstad Carrier fitted with CrossCutter discs designed to work at just 2-3cm is now being used.
“This still provides a good black-grass chit, but without the detrimental effect of the deeper rotary cultivation,” says Mr Atkinson.
Straw raking has proved very useful where a light cultivation is not required, spreading crop residues and giving a good chit of volunteers and grassweeds, offering a step up in soil health terms through less soil disturbance, he adds.
However, the cover crop/ spring wheat sequence has been so successful that stimulating a pre-cover blackgrass chit is not always required.