1. The use of the Mesonet in Oklahoma agriculture Clint Dotson Precision Ag April 16, 2007

2. Outline of topics Overview of the Mesonet and how it works How Oklahoma Agriculture is currently using Mesonet data How Precision Ag benefits from the Mesonet How the Mesonet will be used in the future to fine tune top-dress nitrogen fertilizer recommendations

3. Overview of the Mesonet

4. What is the Mesonet? The Oklahoma Mesonet is a world-class network of environmental monitoring stations. The network was designed and implemented by scientists at the University of Oklahoma (OU) and at Oklahoma State University (OSU).

5. How does it work ? The Oklahoma Mesonet consists of over 110 automated stations covering Oklahoma. There is at least one Mesonet station in each of Oklahoma's 77 counties.

6. All 110 Oklahoma Mesonet Stations

7. How does it work? At each sight the wind speed soil temperature and ambient temperature is measured by a set of instruments located on or near a 10-meter-tall tower. The measurements or "observations" are packaged together and sent every 5 minutes to a central facility readings are taken every five minutes 24 hours a day all year round

8. What is measured at all Mesonet sites air temperature measured at 1.5 meters above the ground, relative humidity measured at 1.5 meters above the ground, wind speed and direction measured at 10 meters above the ground, barometric pressure, rainfall, incoming solar radiation, and soil temperatures at 10 centimeters below the ground under both the natural sod cover and bare soil. air temperature at 9 meters above the ground, wind speed at 2 and 9 meters above the ground, soil moisture at 5, 25, and, 60 centimeters below the ground, soil temperatures at 5 and 30 centimeters below the ground under the natural sod cover, and soil temperature at 5 centimeters below the bare ground.

9. How does it work? The OCS or Oklahoma Climatological Survey then takes these “packaged observations”, verifies that they are quality data and then posts the data online for Mesonet customers. It only takes 5-10 minutes between when the data is collected to when it is posted. This ensures that the data you see is the most accurate and up-to- date information available. (http://www.mesonet.org/overview/)

10. How is Oklahoma Agriculture using Mesonet Data? Ambient temperature and soil temperature Can be used to determine if soil temperatures are right to plant, and can be used to see if current ambient temperatures are cold enough for long enough to harm your crop

11. Example of what the Mesonet can do

12. How is Oklahoma Agriculture using Mesonet Data? Rainfall accumulation and soil moisture If a producer knows what the soil moisture is, they can derive if there is adequate moisture to plant, and if there is enough moisture in the soil profile to sustain the crop throughout the growing cycle.

13. Fractional Soil Moisture map of Oklahoma as of April 5, 2007 http://agweather.mesonet.org/soil/default.html

14. How is Oklahoma Agriculture using Mesonet Data? Wind speed and direction can be used to determine if you can spray, and if you can, which way and how much will it drift

15. How Precision Ag benefits from the Mesonet Oklahoma Farmers who use the N-rich strip or N-Ramp are particularly lucky to have The Mesonet as it is a source of growing degree days. Other states and countries must calculate GDD>0 manually.

16. Areas outside Oklahoma must calculate their own GDD>0 http://www.soiltesting.okstate.edu/SBNRC/ SBNRC.php http://www.soiltesting.okstate.edu/SBNRC/ SBNRC.php Users within Oklahoma have the benefit of having the GDD>0 calculated for them

17. How the Mesonet will be used in the future to fine tune top-dress nitrogen fertilizer recommendations

18. Soil Moisture Volumetric water content Volumetric water content is defined as the total volume or percent of water per volume of soil. This will tell you if you have enough moisture to sustain the crop throughout the growing cycle.

19. Fractional Water Index Has a range from 0-1 therefore the FWI will extend from 0 for a powder dry soil to 1 for a saturated soil. Optimum water for plant growth is between 0.7-1.0

20. Soil Moisture Other factors to consider Very sensitive to the composition of the soil and is greatly influenced by Size and shape of soil particles Total pore space within the soil Organic material

21. Soil Moisture What we are doing Interactive Index of soil types that will tell us if we can sustain a certain crop on a certain soil type with the water that is available. By knowing if the crop can be sustained with the water that is currently in the profile, we can decide on the amount of fertilizer to apply. We will do this by adjusting N rates based on soil profile moisture levels

22. Resources The Oklahoma Mesonet at (http://www.mesonet.org/overview/)http://www.mesonet.org/overview/ Dr. Bill Raun, Department of Plant and Soil Sciences Dr. John Solie, Biosystems and Agriculture Engineering Albert Sutherland, OSU Mesonet Agricultural Coordinator