Black Layer
What is it?
When soil conditions are saturated or waterlogged, and drainage is impeded the water will push air out of the spaces in the soil normally filled by Oxygen. This creates anaerobic conditions. The resulting anaerobic bacteria produces Hydrogen sulphide gas which is poisonous to plant roots.
What are the symptoms?
The Hydrogen sulphide reacts with metals in the soils to create the tell-tale black layer which can appear in bands or be continuous, there is also a foul smell to the soil likened to rotten eggs. On the surface you will likely see yellowing turf that is thinning
What soils are susceptible to Black Layer?
Black layer is most common in poorly draining sand-based soils, but it can happen in other types too
Management
Ultimately improving the movement of water through the soil will help alleviate the conditions in which black layer might develop, soil compaction through traffic, play and certain operations like rolling reduce the pore spaces in the soil which will worsen the drainage characteristics.
Cultural
🌿 Deep spiking, coring, slitting, surface aeration to aid water penetration and de-compact soils. 🌿 Avoid over irrigation particularly any that creates standing water.
🌿 Improvements to surface and sub surface drainage.
🌿 Reduce use of sulphur containing fertilisers as excess sulphur is associated with reduced oxygen levels in the soil.
Chemical
Soil conditioners are available for the treatment of Black Layer these can be in granular or liquid form and usually contain carbon that helps to absorb the poisonous gasses and soil penetrants to improve the movement of water. This may sometimes be necessary in combination with deep spiking in the worst cases.
