AMES, Iowa – Micronutrients are needed in very small quantities by plants, but are essential for their growth and production. A search for understanding how micronutrients can be better managed in the Midwest’s soybean fields has led to new research and a regional publication on the topic.
This research and general management guidelines are summarized in the publication “Micronutrients for Soybean Production in the North Central Region” (CROP 3135) and is available through the Iowa State University Extension Store. Antonio Mallarino, professor and extension specialist in agronomy at Iowa State University, led a team of researchers and fertility extension specialists from five universities across the Midwest who worked on the project.
“This publication is intended to be a resource for farmers and crop advisers of the North Central Region regarding micronutrient use in soybean production,” Mallarino said. “Its purpose is to provide information on micronutrient requirements by soybean, factors that influence their utilization and the value of soil and plant tissue testing.”
Mallarino oversaw about 100 recent trials in Iowa, with researchers from the University of Minnesota, Kansas State University, University of Wisconsin and Purdue University developing many other trials.
“The team effort also included reviewing research that had been conducted in other states of the region during the last few decades,” Mallarino said. “This publication wasn’t done to establish specific recommendations for each state but to give a global view of the issues useful for the entire region.”
The team’s work showed that micronutrient deficiencies have been observed in specific soil types or conditions. Course textured soils, highly eroded soil that has lost organic matter and highly calcareous soils proved to be more susceptible to deficiencies than other soils.
While in Iowa micronutrient deficiencies in soybean are uncommon except for iron in highly calcareous soils, it is still important to monitor crops to make sure they are healthy, Mallarino said. The publication discusses the use of soil and tissue testing to ensure farmers and crop advisers have a proper understanding of their value and potential problems.
“In spite of recent research, the value of soil testing and tissue testing for micronutrients involves more uncertainty than it does for other nutrients,” Mallarino said. “Farmers should make sure not to consider soil and tissue testing results blindly, but keep a watchful eye on their fields where soil deficiencies can be detected.”
The research and publication were funded through a grant from the North Central Research Program.