Authors: Stuti Sharma, Steve Culman, Anthony Fulford, Laura Lindsey, Douglas Alt, and Grace Looker
Micronutrients play important roles in plant growth and development, as such, farmers have long sought after information regarding the efficacy of micronutrient fertilization to increase crop yields. To answer this, we compiled 40 years of data from the Ohio State University consisting of micronutrient fertilizer trials in three crops: corn, soybean, and alfalfa. The results was a database with a total of 194 trials, randomized and replicated, across 17 Ohio counties. From these studies, it was found that micronutrient fertilization rarely produced a significant yield response. Of the micronutrients (boron, chlorine, copper, iron, manganese, molybdenum, zinc, and nickel), manganese or a blend of manganese with other micronutrients increased soybean yield (9 out of 144 trials), boron had no effect on corn grain yield (8 out of 9 trials), and micronutrient fertilization affected alfalfa yields in 17 trials.
These results are not uncommon as there is a large degree of uncertainty concerning micronutrient fertilization needs of crops as soil test critical levels are difficult to develop. Therefore, seeing a yield response to micronutrient fertilization is much more common in situations of known or suspected deficiencies. If you decide to apply micronutrient fertilizers, we suggest leaving an unfertilized strip as a check or control measure. You can then compare your fertilized versus unfertilized yields to determine if the fertilization was effective in increasing yield and whether it provided an economic benefit.
The results of our study can be found on ohioline here