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2000, No. 1
Sunshine Go Away Today
There are a few things turfgrass managers can do to prepare their turf for summer when above normal temperatures and inadequate soil moisture in the spring are predicted.
(These things do not include washing and waxing the family vehicle, doing a little rain dance, or even writing a turfgrass tip on drought stress; although if they produce the rains we need, who is complaining?)
A spring drought is not a common occurrence in our region.
Usually we battle the opposite, too much water.
But when we face the conditions that are occurring at present, we may need to re-think the cultural practices that affect our turf.
The main cultural practices to asses this spring are irrigation, fertilization, cultivation and mowing.
Though it may seem strange to worry about these practices now, the spring is the best time to prepare the turf for the unknown events of the summer.
Though water deficits could be an issue this summer, heat stress will surely be present.
The better we can prepare the turf during this unusual spring for the regular stresses of summer, the easier your job will become.
Because most highly managed turf is irrigated, a spring drought does not seem too awful except under a "grow in" condition or when healing a turf from the previous season's hardships.
Under normal circumstances a spring drought is more easily managed than a mid or late-summer drought because temperatures are moderate.
During the middle of summer it is often difficult to separate the effects of drought and/or high temperature stress on turf injury.
During times of cooler temperatures, evaporative demand is much reduced.
With normal rain patterns in spring, it is common for our turfs to receive water throughout the root system.
Deeper, infrequent irrigation events encourage deeper roots.
This practice should be used this spring to simulate rainfall events common to spring.
Light and frequent irrigation programming should be saved for summer.
In most cases, nitrogen fertilization controls the growth rate of turf, this is no secret.
As plants grow, they consume more water.
Studies have shown as plants receive increased rates of N (nitrogen), their water use rates increase.
Plants that increase their leaf surface area, internode length, and vertical leaf extension rate will also increase water use.
Cool season turfgrasses grow best in the spring and fall when temperatures are cool.
Thus, adequate amounts of N. are imperative in building a healthy turf before the decline in growth occurs with the onset of summer.
As summer approaches, and temperatures rise, N fertility rates should fall.
Encouraging top growth in the middle of summer with excessive N fertility moves internal plant energy from the root system to the above ground growth, which is mowed off and wasted.
Adequate levels of potassium (K) will help to increase drought, heat, cold, and disease resistance.
Potassium fertilization programs should be based upon soil test results.
Though soil compaction reduces the amount of water used by the plant this is not a cultural strategy to manage water use.
The reduction in water use rate by the plant results from reduced root growth that in turn reduces shoot growth.
Cultivation of soils under turf should be done when the turf is actively growing.
This aids in the recovery of the plant and decreases annual weed invasion.
If the turf is in need of cultivation this spring, it is recommended it be done early so that the turf still has time to repair itself.
Cultivation will allow the plant roots space to grow into and thrive, while increasing the infiltration of water and nutrients to the root system.
As with cultivation, an increase in the mowing height of our turfgrasses also increases water consumption by the plant.
Plants that have more above ground shoot mass, will have a higher water use rate.
But, more importantly there is a direct correlation with higher mowing heights and greater root mass.
By raising mowing heights this spring you can ensure greater root mass of your turf for the summer stresses it will inevitably face.
Another method of controlling plant water use is by chemical means.
Growth regulation is another water saving strategy to manage plants under moisture stress.
Plants treated with growth regulators are more compact with slower growth rates.
This can lead to reduced plant water use throughout the whole growing season.
Proper cultural practices employed early this spring will your turf prepare for summer stresses.
Proper irrigation timing and frequency, adequate fertilization, and cultivation are steps you can take to ensure turf health this upcoming season.
Updated on October 16, 2000
(Luke Cella, Tom Voigt, Bruce Branham)
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