- Question from volunteer groundsman, Chesterfield.
A: There could be a number of reasons why the water isn't travelling through the soil profile. It may be sitting on the surface because it can't pass through a thick layer of thatch, or because the soil is heavily compacted. You should check for both of these and, if necessary, scarify and aerate as and when appropriate.
More likely, it is a combination of the above plus the fact the soil has become water repellent - a problem that is even more likely on older, and free-draining, greens. If you take a sample of soil you will probably find it's bone dry, musty smelling and might contain specks of white fungal growth. These are the classic signs of a hydrophobic soil and it will result in brown patches of grass that are stressed due lack of moisture uptake.
In hot, sunny spells, the problem can become serious and action needs to be taken because when hydrophobic soils dry out, they can be difficult to re-wet - as you know. Water from irrigation systems will run-off, evaporate and be wasted. It is important to sort out water management at soil level.
Hydrophobic conditions in relation to soils are often caused by waxy coating forming on the soil particles. The coating may form as a result of wax eroded from plant leaves, exudates from plant roots and fungi, decomposing organic matter and waste products from various biological sources, including microbes. Various wetting agents are available to manage water within the soil.
Vitax offers the most comprehensive range of water management products available from a single source. There are products to cure and prevent hydrophobic soils, help reduce run-off from slopes and lessen the risk of water logging.
Aqua-Aid, for instance, is a penetrant wetting agent that uniformly disperses water throughout the soil profile and increases nutrient uptake. It is formulated with non-ionic surfactants and wetting agents and works by modifying surface tension. Vitax says by doing this, the amount of irrigation required can be reduced by 30 per cent, which is important when trying to save water.
You can find out more about Vitax water management products and how they encourage healthy root and plant growth at www.vitax.co.uk.
Many other companies also offer wetting agents and water management solutions. Rigby Taylor (www.rigbytaylor.com) has just introduced Breaker BioLinks, which it claims offers increased curative powers against dry patch. Breaker BioLinks is a combined force of three surfactants and a complex of integrated plant-growth hormones.
A total water management solution available from Scotts (www.scotts professional.com), H2Pro, contains two separate surfactant systems - wetting and spreading agents, and long-term wetting agents. Like the other products it can be used all year round, as and when required.
All the products can be used as curative treatments, but for greatest effect you should think about an application programme. The latest wetting agents are usually most effective when the initial application is made before the growing season, with further ones later.
Sally Drury has reported for HW and its forerunner GC&HTJ for 27 years and has spent more than five years testing machinery for HW and What Kit? The advice in this helpline is independent.