Using computer modeling tools to simulate dry weather conditions at corn planting can show the effect of dry soil conditions on potential yield. The corn simulation model Hybrid-Maize can address several questions regarding corn management. It allows users to change soil moisture conditions at planting time to simulate what the outcome would likely be if you tried different management practices.
Iowa State University Extension agronomist Roger Elmore has used the model to answer the question: Should you consider planting lower corn plant populations if it is dry this spring? The model uses historic weather data from automated weather stations. In this case, he used data from seven of ISU's research and demonstration farms around the state -- one in each of the four corners of Iowa and the others in northern and west central Iowa and one at Ames.
Computer program lets you plug in different soil moisture conditions at planting time to see what the effects would be on yield, assuming continued dry weather
The model lets users change soil moisture conditions at planting to simulate different possibilities. Elmore has compared two scenarios: 1) Normal: 75% field capacity of moisture in topsoil (0-12 inches) and 100% field capacity of moisture in subsoil; 2) Very Dry: 25% field capacity in both topsoil and subsoil. "Given the two soil moisture scenarios at planting, the model allows us to estimate the effects of changing corn plant populations at planting time, as well as other factors, on simulated yield," he explains.~~~PAGE_BREAK_HERE~~~
Elmore's two articles "Corn and Dry Soils at Planting, Looking Ahead to 2013," Part 1 and Part 2 are in ISU's ICM newsletter. The articles were published online on the ISU site on February 11, 2013.
In the "Part I" article he looks at the yield effect of planting a reduced seeding rate if it is dry at planting time. In the "Part II" article he looks at the yield effect of planting earlier-season maturity corn hybrids if it is dry at planting in 2013.
Modeling tools that simulate dry conditions at planting helps users understand the effect of dry conditions on potential yield. The corn simulation model Hybrid-Maize can address several questions regarding corn management practices. This "Part 1" article examines the effect of planting a reduced seeding rate in a dry season.
The Hybrid-Maize model allows users to change soil moisture conditions at planting to simulate different possibilities. This capability allows you to simulate conditions with only half of the normal field capacity of soil moisture at planting.
This "Part 2" article examines the question: Should you consider planting an earlier-season corn hybrid if it is dry at planting in 2013? In the more southern parts of the Corn Belt, farmers often plant hybrids that are five or 10 or more days earlier than typical adapted hybrids in an effort to avoid late-summer heat and drought. Will this approach work in Iowa if our soils remain dry at planting? Elmore's article answers that question—which you will find out when you read it on the ISU ICM newsletter website.