Increasing Interest in No-Till
In a classroom setting, if one student asks a question, it is a good assumption that many others were also thinking about it. If that holds true for farmers, then quite a few southeast Kansas producers are considering converting to no-till or at least minimum till, operations.
Multiple producers have mentioned there biggest concern with converting to no-till is the cooler soil temperatures, especially during corn planting. In an effort to quantify the difference, I downloaded information from the Oklahoma Mesonet website for the four locations nearest southeast Kansas (Copan, Miami, Nowata, and Vinita).
While there is tons of valuable information available for anyone to access on their site, I focused on the 10 centimeter (cm) soil temperatures under bare soil and sod covered conditions since January of 1994. The bare soil is meant to simulate a conventional tillage operation while the sod covered would simulate a no-till situation. I freely grant this is not the exact conditions that will be present in the field.
On average, the daily mean temperature from the bare soil is around 1.1 to 1.2 degrees Fahrenheit warmer than the sod covered soil. The fact that the bare soil is warmer is not that surprising. However, the relatively small difference may surprise some.
An interesting discovery comes when looking at the averages month by month. From October through February, the sod covered soil temperature is warmer than the bare soil. In fact, it is on average 1.28 degrees Fahrenheit warmer. This is due to the insulating effect of the cover.
From March through September, the bare soil is 2.88 degrees Fahrenheit warmer than the sod cover. Once again, the cover insulates the soil below it and buffers the change in temperature.
In reality, a yearly average isn’t as important to corn planting as the soil temperatures in March and April. On average for the four Oklahoma Mesonet sites, bare soils in March and April are 0.7 degrees Fahrenheit and 1.45 degrees Fahrenheit warmer than the sod covered soils respectively. Once again, the fact that bare soil is warmer is not unexpected but the limited extent that it is warmer may be surprising.
In fact, if we dig a little deeper, the most important figure is which date the soil temperature rises above 55 degrees Fahrenheit. On average, since 1994 under bare soil the average soil temperature first hits 55 on March 15th while under sod it occurs on March 25th.
While the first date the soil hits 55 degrees Fahrenheit differs by ten days, probably a more important figure would be when the soil temperature consistently stays above 55. Once again there is a difference, but it is probably smaller than may be expected. Under bare soil conditions, the soil consistently stays above 55 on April 7th while under sod, that date is April 8th.
It must also be pointed out that producers have other concerns when considering converting to no-till. These include but are not limited to too much soil moisture in the spring and potential weed management issues.
Is soil temperature a concern when transitioning to no-till? While there is a difference, it may not be as substantial as assumed. If you have questions or would like more information, please call me at the office (620) 724-8233, or e-mail me at jcoltrain@ksu.edu, or visit the Wildcat Extension District website at www.wildcatdistrict.ksu.edu.
Contact:
Josh Coltrain
Crop Production and Local Foods Agent
Wildcat Extension District
jcoltrain@ksu.edu
(620) 724-8233
K-State Research and Extension is an Equal Opportunity Provider and Employer
