#12 @ Wild Horse

#12 @ Wild Horse

Sunday, August 17, 2014

Irrigation Management

August 17 --July turned out to be the driest on record with a scant .25" here at the course.  Luckily the temperatures were moderate and the turf fared pretty well.  We received an inch and half of rain last week which helped alleviate some of the browning of the hills and fairway edges.  Many people do not like that off color of the turf, but if little rain falls for a month and there is no browning of certain spots on the course, then overwatering is occurring.  We are constantly monitoring soil moisture levels and eyeballing to the turf to make daily adjustments to our irrigation regime.  We strive to provide the turf with enough moisture to stay healthy without overdoing it- a happy medium I guess you might say.  However some spots don't receive great irrigation coverage and will go dormant which is ok.  Bluegrass is expecially drought tolerant and will rebound nicely once it receives rain or extra irrigation.  
However there are some problems with keeping turf on the drier side as shown below.

As you can see here cart traffic is especially damaging to turf under drought stress.  This happens more on a hot days but can happen anytime but the damage is usually less apparent.  This picture shows damage from a couple weeks ago when we had irrigation motor issues and were not able to water all of the course for a couple of days.  Luckily, as I stated before, the bluegrass is especially adept at going into dormancy and surviving such stresses but it does look unsightly for awhile. 

Here is an interesting picture that illustrates how we try to maintain just the right soil moisture.  What you see here is a low spot in 3 fairway.  You would naturally think that this spot should be wetter than the surrounding area since it is a large bowl.  So why is it showing drought stress?  Those two circle you can see are grates over french drains that were installed during construction.  Basically, a large hole was excavated and filled with gravel and sand to drain rainwater away in this catch area.  So what you are seeing is the "sump" that has a coarser sand that holds less water than the surrounding soil.   Usually this browning will occur after a rainfall because we will withhold irrigation until the turf starts needing it. This is a good indicator that soil moisture is starting to be depleted and irrigation will be necessary soon.  A couple of irrigation cycles will replenish the soil moisture in the sump and it will recover but it is pretty odd to see the lowest spots on the course brown and everything else green.

Fall is just around the corner which means some upcoming aerification and overseeding.  This week we will be doing both to our surrounds and will once again be spraying Tenacity to alleviate bentgrass.  You can learn more about this process if you scroll down to last years posts about our "white grass"!