Soil health has a big impact on yields of grass and forage so limiting compaction is an important way to get more feed from grassland.
Hefin Llwyd, Farm Adviser for GrowHow has looked at the latest research to give us his top tips about compaction.
Protect yield: Work by SRUC at Crichton Royal Farm in Dumfries shows 15% grass yield loss in swards with compaction caused by poaching and losses of 20–25% from wheeling.
Compaction wastes nutrients: Fertilisers and slurries applied to compacted soils are used less efficiently; sorting out compaction will mean a better return from nutrients.
Prevention is better than cure: It is not possible to stop all compaction but there is plenty you can do to limit it. Restricting grazing time during very wet weather will reduce poaching. Controlled traffic farming by sticking to tramlines will limit deep compaction.
Dig to look at the soil profile: Inspecting the soil is vital so you know the best way to deal with the problem. Compaction in the top 3–4cm indicates trampling by sheep, problems down to 10cm will be from cattle and a compacted layer at 15cm indicates that wheeling was the cause.
Use spiking to deal with trampling and poaching: Spike aeration can help with compaction at the top of the soil profile. Make sure the field will take machinery and the spikes slit the soil to below the compacted layer.
Lift swards in autumn: Sward lifting or sub-soiling deals with deeper compaction caused by wheelings. It is best to do it in autumn to give the soil and grass time to recover before spring growth.
Lift as ground is starting to wet up in autumn: Lifting is not effective in very dry conditions but avoid when it is too wet as you can cause more compaction than you solve.
Check what you have done: Dig soil pits during and after treatment to make sure that treatments have worked.
