DEFRA’S Farming Advice Service’s latest technical article has been published, with advice on managing wet soil.
Good soil structure is essential in optimising crop yields. Soil damage may have occurred due to harvesting in wet conditions. Careful inspection of the soil structure needs to be undertaken to ensure the correct remedial action take place.
In order to comply with Cross Compliance, it is important that any mechanical field operations, including harvesting, carried out on waterlogged soil are recorded in the Soil Protection Review 2010 under ‘Access to waterlogged land’ (pages 44-46). Appropriate action to remediate damage caused by accessing waterlogged soil must be done as soon as possible within 12 months of the first month of access to the waterlogged field. This action is in addition to any other actions identified in the Farm Soil Plan.
Soils structure should be assessed as soon as possible, ideally by the end of February when the damage is more visible.
An action plan can then be put in place which identifies fields which have the most severe damage, which can then be prioritised for remedial action when the soil is dry enough for repair. It is unlikely that much soil damage can be repaired in the spring as there needs to be a sufficient dry period. The topsoil and the subsoil should be assessed separately by digging a hole to the appropriate depths – normally 25cm for the topsoil and 35cm for the subsoil – and looking carefully at both types of structure.
If there is no compaction present, the topsoil will present a crumbly face throughout the topsoil profile and, in this condition, every part of the soil profile can be accessed by the plant roots.
If the topsoil is suffering from compaction it can inhibit root growth and nutrient uptake causing nutrient deficiency leading to a loss of yield.
The subsoil should provide a structure which is able to support the topsoil while having enough fissures within it to allow for good drainage of the soil. It should also allow the root systems to travel down these cracks looking for soil moisture when the plant has a high moisture requirement in the spring and summer. Therefore, the subsoil naturally wants to look ‘angular’ and ‘blocky’ but with vertical cracks within it to allow for drainage to occur.
The worst damage is normally shown within 7cm of the bottom of the wheeling. Therefore, depending on the depth of the rut that has been formed, the depth of remedial action can be determined.
Remedying topsoil damage can be relatively easy once the depth of the compaction has been assessed. An implement running 2.5cm below the depth of compaction should be able to alleviate the problem.
Where damage has been more severe and compaction to the subsoil has occurred (which will show as a rutted field with standing water), then it is likely to have impeded drainage and the soil will need to be drained before any remedial action can be considered.
The Farming Advice Service offers guidance on a range of issues including Cross Compliance, nutrient management, climate change and competitiveness. We provide advice through group meetings, events and a technical helpline.
If you have any further queries relating to this article or any other FAS subject areas, contact the helpline on 08453 451 302. For general inquiries email firstname.lastname@example.org Website: www.defra.gov.uk/farming-advice