I have been asked on occasion why we put down so much water on the greens and why they seems soft or slow.
Here is a article form Pace Turf that explains the reasons why we perform this procedure.
Leaching: Why is it Necessary?
Bottom line:
Greens leaching programs are designed to keep turf healthy by reducing soil salts. Unfortunately, there are some temporary side effects — wet greens and surrounds, softer turf, and slower greens. Are the benefits of leaching worth the inconvenient side effects? The answer is definitely “yes”, and we will explain why here.
Salts, deadly poison for turf: What do you think is the most serious problem affecting the health and quality of putting greens? Most people believe that diseases, insects or weeds are the biggest threats, and indeed these pests can cause significant turf damage. But an even more serious threat is the build-up of soil salts.
The importance of rain: When there is enough rain, salts are rarely a problem. This is because rain helps to leach, or wash away, the salts that accumulate near the soil surface. Rain pushes salts down into the soil, beneath the area where plant roots grow.
But during periods of low rainfall, this natural leaching does not occur, and salts build up.
Salts hurt turf in three different ways: The most important of these is known as physiological drought. When this occurs, the plant can’t get water from the soil, even when the soil is moist; this isbecause salts in the soil literally suck water away from the plant roots. The effect can be devastating, particularly to salt-sensitive turf such as annual bluegrass and bentgrass.
Secondly, accumulation of sodium salts in the soil damages the structure of the soil itself. This can result in poor drainage, low soil oxygen and poor water infiltration – all of which result in even more stress to the turf.
Finally, salt stress on turf makes it more susceptible to diseases, weeds and insects.
The key is to keep turf healthy by avoiding the build-up of soil salts BEFORE damage to turf occurs. And the best way to avoid salt build-up is to implement a leaching program.
It’s all about balance: Maintaining a balance between soil salts and turf quality is a significant challenge.
To keep salt levels low, it is necessary to conduct leaching programs during periods of low rainfall. High leaching volumes (a few inches of water in an 8-hour period) of irrigation water are required to drive salts below the root zone.
This is why greens and surrounds can be soggy and soft following leaching. But the benefits are enormous. When done on a preventive basis– before turf damage due to salts is serious – turf and soil will become healthier, pest damage will decrease, and greens will remain green. It’s just that simple.
©2010 PACE Turf, 1267 Diamond Street, San Diego CA 92109 www.paceturf.org
