Compaction affects grass yields
RECENT wet weather may have adversely a
ected soil structure, particularly if grazing or tra c was necessary during this period.
Research from
SRUC indicates that soil compaction can significantly decrease grass yields. Specifically, the yield of first-cut grass silage was found to be up to 37.7% lower due to tractor compaction and 19.0% lower as a result of cattle trampling, when compared to an uncompacted control area.
To determine if compaction could hinder production, consider the following steps when the soil starts to dry out:
1. Examine soil structure – Excavate a spade-sized pit and inspect a clean side of the pit for ‘limiting layers’ – distinct horizontal layers that dier from other soil depths. Look for soil clumps that do not break down to less than 5cm, red/
orange patches, and roots concentrated in large pores. Soil with a poor structure might emit a sulphuric odour.
2. Locate the compaction – Measure from the soil surface to pinpoint the depth where this compacted layer exists.
3. Plan remediation – Address severely compacted fields when the soil is dry but not excessively so, as overly dry conditions can cause root damage, making the grass more susceptible to drought. It’s preferable to conduct remediation activity in autumn, if soil conditions are favourable, as there is oen a yield penalty initially due to the root disturbance.
However, if conditions become suitable in the spring, you might want to make the most of the opportunity.
Techniques for dierent depths – If the compaction aects the top 10cm, use a sward slitter or aerator. For deeper compaction beyond 10cm, a sward lier should be used. In cases of severe compaction, it might be necessary to plough and reseed the area.
Natural remediation for mild compaction – For less critical compaction, allow natural processes to aid recovery prevent further compaction; rest the field more than usual, or defer using the grass until later in the year.
Implementing these measures can help maintain soil health and ensure continued productivity despite challenging weather conditions. Always consider the specific needs of fields and adjust management practices accordingly to optimise the conditions for crop growth.