Kansas State University

search

K-State Turf and Landscape Blog

Tag: mesonet

Wet Spring will Likely Lead to Quick Drought Response as Summer Approaches

By Jack Fry, Professor and Commercial Turf Extension Specialist

It’s been a wet spring through much of Kansas.  In Olathe, KS there has been 11.3 inches from March 1 to June 10.  Frequent rainfall reduces the necessity for grasses to produce deeper roots, and also enhances more shoot growth.  As summer approaches and an extended period of time without rainfall occurs, drought stress will be occurring more rapidly that it sometimes has.

Uniform irrigation is important so that water is distributed nicely over a lawn, golf course, sports field, or other area.  In addition, you can estimate the amount of water that has been lost from the turf over time, which is called evapotranspiration (ET).  Evapotranspiration includes water evaporation from the soil and transpiration from the leaves.  Here is a site from Kansas State University that provides weather information and allows you to determine the level of ET that has occurred:

https://mesonet.k-state.edu/

You can click on the location near you on the KS map when this website comes up.  Then, go to the upper left corner of mesonet (click on the 3 lateral bars) and select any information desired.  To determine water use, go to weather – historical weather – enter the dates that are of interest for you.  After doing so, click submit and you’ll see weather details returned.  On the far right of the image, click on grass ET and you’ll see an estimate of ET for that area.  Here’s an example of the ET that I looked at for Olathe, KS:

The ET that you see is based upon a formula called Penman-Monteith, which uses temperature, humidity, solar radiation, and wind to create the estimate.  As a reminder, the ET that you view is based upon assumption that the soil moisture is high.  In other words, as soil dries down in a turf area, the ET is likely going to be lower than estimated on this site.  That said, this information is useful to provide guidance on the amount of irrigation that may be needed to apply to the turf area. To confirm the amount of water applied from your irrigation system, use a sprinkler gauge that indicates the amount of water applied for a given amount of time.

Deeper, less frequent irrigation will enhance rooting as time progresses.   To do this, you may desire to wait until you begin to see wilt occurring on the turf.  As an alternative, you can determine what the soil moisture measurement is when wilt is just beginning and irrigate just prior to that soil moisture level.  As summer heats up and less rainfall begins, it is quite likely that following this strategy will still require irrigation be applied often due avoid extensive wilt.  It is possible that over time, irrigation frequency can be reduced.

There are number of different research articles below that demonstrate all turf species can get enhanced rooting with a deeper, less frequent irrigation strategy.

Tall Fescue:

Huang, B. and J. Fu.  2001.  Growth and physiological responses of tall fescue to soil surface drying.  Intl. Turfgrass Soc. 9:291-296.

Fu, J., J. Fry, B. Huang.  Tall fescue rooting as affected by deficit irrigation.  HortScience 42:688–691. 2007.

Creeping Bentgrass:

Fu, J., P. Dernoeden.  2009.  Creeping bentgrass turf response to two summer irrigation practices: rooting and soil temperature. Crop Sci. 49:1063-1070.

Jordan, J.E., R. H. White, D.M. Vietor, T.C. Hale, J.C. Thomas, and M.C. Engelke.   2003.  Effect of irrigation frequency on turf quality, shoot density, and root length density of five bentgrass cultivars.  Crop Sci. 43:282-287.

Zoysiagrass:

Qian Y. and J. Fry.  1996.  Irrigation affects zoysiagrass rooting and plant water status.  HortScience 31:234-237

Above is the photo from the zoysiagrass research noted above in 1996 (a number of years ago). The zoysia on the left had been irrigated daily for an extended period of time and then water was turned off.  On the right, zoysia had been irrigated deeply and infrequently (based upon ET measurement) and then water was turned off.  Obviously, the deeper, infrequent irrigation enhanced its tolerant to drought.

Wind Chill Analysis Tool from Kansas Mesonet

By Christopher “Chip” Redmond, Kansas Mesonet Manager, via Agronomy eUpdates

The forecast for the coming week consists of bitter cold air, the coldest of the 2023/2024 winter season thus far. However, the temperature does not always give the air that nip. The “feels like” temperature is also usually influenced by the wind. We call this the wind chill.

What is the wind chill?

When temperatures drop below 50oF and wind speeds are greater than five mph, the “Feels Like” temperature is lower than the actual temperature. Wind chill can be calculated in two ways: 1) using the chart below or 2) mathematically. Wind chill values decrease as the wind increases and/or the temperature decreases. This means that despite it being 0oF on a very cold morning when factoring in the wind (for example, 20 mph), it can feel like a much colder temperature (in this example, -22oF).

This colder “feels like” temperature can make you feel chilled quicker and lead to other problems such as frostbite much quicker. Exposure time estimations of frostbite issues at 0 degrees F with no wind is 30 minutes, while 0oF and 55 mph winds are less than 10 minutes of exposure. Wind chills can be determined by the following chart from the National Weather Service (https://www.weather.gov/safety/cold-wind-chill-chart):

Where can you access wind chill data?

The Kansas Mesonet makes viewing the wind chill very easy! We have put together a webpage depicting the current wind chill via a gradient map here: https://mesonet.k-state.edu/weather/windchill/. It can also be accessed via the menu in the top left (Menu à Weather à Wind Chill)

The map defaults to the current wind chill but also has a selection at the top where you can change the map to view temperature and wind speed/direction. Since these are the two ingredients for the wind chill, it tells the complete story. The table below the map also displays each station’s wind chill, temperature, and wind data in sortable columns. By clicking the column headings, that particular column will sort from lowest to highest values. Click it again, and it will reverse the order. You can also select a specific station either on the map or in the data table, and it will display the specific information for that location.

How many hours has the temperature been below freezing?

Winter wheat and cover crop producers still have an interest in the cold temperatures. The freeze monitor data is available on our webpage as well. It allows you to track the hours below 32 or 24oF thresholds useful for permafrost development or winter wheat/cover crop damages.  You can access this information via the menu in the top left (Menu > Weather > Freeze Monitor) or at mesonet.ksu.edu/weather/freeze

Stay warm and safe on these chilly days! Winter has only just begun.

Cooler weather brings the return of the Mesonet Freeze Monitor

(Chip Redmond, Mary Knapp and Dan Regier; Weather Data Library/Mesonet)

Cold weather is making its appearance with frost advisories issued this last weekend and freeze warnings this week. The average freeze date in northwest Kansas is as early as the last week in September. However, southeast Kansas does not usually see freezing temperatures until the end of October. Average dates for the first occurrence of 24-degree F temperatures are even later.

For more information check out the KSU Agronomy eUpdate.

https://webapp.agron.ksu.edu/agr_social/m_eu_article.throck?article_id=2358