Under extreme high temperature conditions – when the temperatures reach the upper 90’s and above – the grass plants will begin to shut down as a defense. In some cases such as with annual bluegrass they often die in a relatively short period time. One of the most important things you can do as a turf grass manager is to try and cool the turf. The best way I know is by a light application of water to create evaporation cooling. If you have an in ground irrigation system this means turning the system on to give you approximately .05” of water. You do not want to flood the turf at this time because you can create scald and cook the grass plants. The timing of this water application ( in this case called syringing) should be just before the hottest time in the afternoon. When I was a golf course superintendent we would begin this around 2 PM.
The infill provides the cushioning of your synthetic field. The surface hardness ( measured by Gmax ) is almost always a direct correlation of your infill levels. The infill levels should be measured regularly and compared to the manufacturer’ s recommendations. How much rubber do you need? As a rule – ½ pound of rubber per sq ft. equates to approximately ¼” of infill per sq ft. For example if an 80,000 sq ft. field is low by an average of ¼” – it will take approximately 40,000 lbs or 20 super sacks of material. It is not recommended that you apply more than 6-10 sacks at any one time – so it may take several applications to get the needed rubber down. Please avoid putting the rubber down in wet conditions or you will have a mess.
In an earlier “Tip” we discussed Bill Bug damage prevention. Unfortunately we are now observing either white grub damage or bill bug larve damage in many fields in Western Oregon. If you have been irrigating adequately and you are suspect that you have the problem – grab the turf in a dry spot and it will come up in your hand with no roots. You may even be able to see the white grubs or bill bug larve present at the tear line. If the damage is still spotty there is probably time to treat the problem. The internet is an ideal place to see pictures of this type of damage.
Have you ever noticed that sometimes no matter how much water you apply to your field that it only soaks into the top half inch or less. The top thatch acts like a sponge but the water is not getting through to the soil beneath. Ample aeration will assist in keeping this from occurring but once it happens the only thing I know that will assist in alleviating this condition is the use of soil penetrants. These compounds can be applied in the liquid or granular form. They reduce the evaporation of water by allowing the water to penetrate into the soil more readily. There are some that work better in sandy conditions and some better with clay and believe it or not some work on all types of soil. Look into this – you will be glad you did.
As a sidelight – remember that good fertility is a great aid in the best utilization of water by the plant. A good example of this is to observe the green spots that come about where pets urinate on an under fertilized field.
This spring has been has been relatively dry. May is what is referred to as a deficit month water wise – meaning that the grass plants require more water than “Mother Nature “ on the average provides. It is for that reason that those irrigation systems should be ready to run and or running now.
Possible Bill Bug Damage?
A year ago we saw the center of a well maintained soccer field go into stress and loose 50% of the turf within 2 weeks in July. We assumed that it was the annual bluegrass dying due to heat stress but we were able to determine that it was a Bill Bug larve infestation that was the cause. The grass plants roots were eaten to the point where they could not survive. This month (early May) the field is being treated to control the damaging Bill Bug larve. On your computer type in “ bill bug damage in the NW” if this looks familiar – do something now.
The best time to work on your infield (baseball and softball) skinned area is now . The months of August and September typically have good weather with little play so that you can get work done, use the field for fall ball, and avoid the significant dangers of an overly soft field in the spring. Following the renovation the first few rains (and irrigation cycles) will still cause the field to become soft (and in most cases unplayable). However, the winter rains will help settle the field for play in the spring. You will still want to do a field drag and topdressing in the spring to get the field in “game shape” but the soil disturbance should ideally be kept to a minimum.
In the northwest we are known for our dry summers coupled with low humidity. It is not unusual to receive very little rain between the last part of June all the way through September. This year’s intermittent rain / thunderstorm events have made the turf very susceptible to what we consider the most devastating of turf grass diseases – pythium blight. Couple heavy moisture with high temperatures and high humidity and the conditions could not be better for disease development. Type in “ pythium blight in the northwest” on your computer and look at the pictures. We have seen this disease already this summer and if you think you have it – you may have to arrest it with a specifically labeled turf grass fungicide. This disease can make an entire field unplayable in a very short order. Cultural practices which are normal for the northwest – regular irrigation – not creating a frog pond – coupled with our lower humidity helps keep this disease under control.
The best soil penetrant is “Mother’s Nature’s” rain. The minute this rain stops and the hot weather arrives – be ready. As was mentioned in a previous “tip” – shallow roots (due to the plant growing in water all spring) are still being supported by rain water and are flourishing. When the fields look great it is easy to put off aeration. According to recent work done at Oregon State University concerning aids that assist in irrigation water penetration (a myriad of products and practices were tested) aerating still gave the best results. So keep those aerators handy.
In the Northwest we are approaching the ideal time of year to plant grass seed if you are intending to get as much help from Mother Nature as possible. Early Fall offers a period of time when the temperatures and precipitation are not in the extremes. (except this week) In general it is the easiest time to establish turf without a great deal of effort.
After seed bed preparation and seeding – the next most important operation is rolling the seed. This is often treated lightly when in all reality it is extremely important. The seed needs to be placed in tight contact with the soil or growing medium in order to keep the moisture that is present moving freely between the soil particle and the seed – otherwise the seeds will dry out prematurely and germination will be limited.
A roller I found to be very effective was not actually a roller but the knobby tires that are found on many ATV’s(all terrain vehicles). The seed is pressed down by the knobby tread and the indentation left by the tread helps hold the moisture. You have fun running the ATV and it really works well.
The soil temperatures will soon be reaching the 53-55 F. degree mark. At this point the grass plants will be able to start using the fertilizer more effectively. In the northwest this usually coincides with the advent of Spring. The day length is at least equal to the night length and therefore this warming happens rather consistently. If you have been using a fertilizer sparingly throughout the cool months I am sure have seen some results. This is due to the shallow surface roots being able to warm instantly due to the solar energy. Now we are talking about the top 2″ and deeper – the effective root zone of the grass plant. By applying fertilizer when the entire plant can respond you are maximizing your dollars spent and your time to do it.
For the grass plant – if you only had one thing you could provide for the whole year – besides water and fertilizer – it should be aeration. After a wet spring and heavy foot traffic the compactions is severe and introducing air into the root zone by removing a soil core makes it possible to go for another season. It is like giving the turf a jump start. The aeration has given the roots the oxygen they need to thrive. By aerating as early as practical in the Spring you are giving the turf the best shot at staying playable for the balance of the season.
The soil test is one of the best money savings tools that is available to those involved in managing turf grass sports fields. All of us who are involved in maintaining turf grass sports fields are well aware of the necessity of fertilizer. Unfortunately, this is often the weakest link in the maintenance program. In many cases, quantity is often mistaken for choosing the right nutrients to get the best result for the amount applied. If the proper balance of nutrients is not available to the grass plant – it will not have a fighting chance of surviving the tremendous traffic demands. Furthermore, a person may be applying fertilizer that has only limited uptake by the plant because the soil may be too acetic or basic. The soil test will show the soil ph often an application of lime to correct the soil ph will save you an additional application of fertilizer. Ideally, a ph ranging from 6.2-6.4 seems the best range of microbial health and nutrient availability.
It is wise to use the same laboratory every time you make a soil test. The data is easier to compare if it is in the same form year after year. The initial soil test that you take will be the benchmark from where you assess your progress. Lastly, when taking the samples to be tested it is important that you keep the depth to the effective root zone of the plant. This is usually no deeper than 4″. The sample you submit should contain soil from at least 5 places across the field.
If you would like to further discuss these comments, please give us a call
@ 503-692-1195, and ask for Dick @ ext 2 or Damon @ext 6.
This is a very good question. The purpose of deep tine aeration on both sand and soil based fields is to expand the root zone by promoting better water penetration through the soil profile. On sand based fields it will break up a cemented sand condition and better promote free drainage. In soil based fields it permits the water to penetrate through a surface compacted layer usually 4-8″ deep beneath the playing surface and then move into the sub soil. In most cases the deep tine work will extend the playing season (earlier in the spring and later in the fall) but is not the “panacea” for full winter play. If the field is built on a heavily compacted base which is generally deeper than 12″- it is possible that the deep tine aeration work is of little use and that installing a drainage system will be the best answer. When you are using a solid tine to fracture the soil are you actually relieving compaction? Probably not. We think of relieving compaction when actual soil is removed with a coring tine. It is possible to core with a 1″ tine to a depth of 10″. Deep coring is readily available and will be discussed in a later article. Please keep in mind the fall over-seeding that was addressed in the October “Tips” article. You can still have seed germinating well into November with some of the new cold temperature germinating ryegrasses.
If you would like to further discuss these comments, please give us a call :
@ 503-692-1195, and ask for Dick @ ext 2 or Damon @ext 6.