Wetting agents – Too Early?

I’m getting a few phone calls at the moment from super organised people out there who are planning their wetting agent programmes for this year.

One of the questions I get asked regularly is how early should I start?

This isn’t a very difficult question to answer, the earlier you start go better. The key to a good wetting agent programme is getting the wetting agent well distributed throughout the soil profile.

Rainfall minus ET in Coventry

When we look at evapotranspiration rates in Spring it becomes clear that soils can easily begin to dry down anywhere from the beginning of March. If this happens to coincide with a period of low rainfall then soils can quickly become dry, particularly in the upper regions of that soil profile where we are hoping to encourage root growth every day temperatures permit. Despite the varying weather over the last 5 years you can see the trend is always for things to start drying down in March.

During the spring the soil temperatures are the key driver for root growth, the increasing daylight is no longer a limiting factor. As we have no control of soil temperatures or daylight the only factor left that we can control is soil moisture. All too often I see surface’s being allowed to dry down during the spring. It’s generally a conscious decision in an attempt to push roots deeper, a belief that roots will go searching for moisture is in my opinion unfounded.

Roots need moisture in which to travel, with the sand top dressing programmes we have in place in modern green keeping and the shallow roots we generally have in early spring most people underestimate just how dry the upper region of that soil profile gets.

By getting a wetting agent down early you increase your chances of retaining moisture in the critical upper profile. You also increase your chances of distributing the wetting agent evenly and thoroughly throughout the rootzone. this is because the soil profile is still evenly moist from the winters rainfall and the even distribution of moisture enables the wetting agent to spread evenly.

If soil profiles are allowed to dry out rewetting them becomes increasingly difficult. As with all things in this game prevention is far better than cure.

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