With bigger and heavier machinery, compaction is becoming a real problem for the industry.

Compaction occurs when a force compresses the soil and pushes air and water out of it so that it becomes more dense. In the soil, this allows platy aggregates to form and the soil tends to crack horizontally rather than vertically. Compaction is more severe when the soil is wet and less able to withstand compression.

The most likely causes of compaction in any situation should be identified and managed carefully. In some situations, damage cannot be avoided completely, but it is important that the risk is noted and the impacts investigated, according to experts from AHDB.

In arable systems the main cause of compaction is machinery damage but in mixed livestock/arable operations damage by livestock is also a major issue.

Naturally, soil structure is formed and then maintained through a range of physical processes (eg wetting-drying cycles, freeze-thaw) and biological interactions (eg plant roots and other ‘ecosystem engineers’). Supporting the biological processes of structure formation and increasing soil organic matter content have been shown to help create resilient soil structures that can increasing bearing capacity and trafficability and allow soils to withstand damage from routine farm practices more effectively.

However, the detailed mechanisms supporting structural resilience in the soil are not yet well understood.

Reducing machinery damage:

Between 50 and 80% of damage by machinery is caused by its first pass on wet ground.

So, if possible keep off wet fields, especially 48 hours after heavy rainfall, when surface soils are wet. If you are not sure, dig a hole and see for yourself how plastic the soil is – check the whole topsoil, even if the surface looks fine. If the soil can make a worm when you roll it between your hands, it is too wet for trafficking.

Where possible reduce ground pressure by reducing machine size and total axle loads, and you can reduce ground pressure by using larger tyres and lower inflation pressures.

Control trafficking on a field and use established wheelings, especially with heavy loads like grain and silage trailers.