Corn, Soybean, and Alfalfa Yield Responses to Micronutrient Fertilization in Ohio

Micronutrients are essential plant nutrients that are found in trace amounts in tissue but play an imperative role in plant growth and development. Without these nutrients, plant nutrition would be compromised leading to potential declines in plant productivity. Of the 17 elements essential for plant growth, eight are micronutrients: boron (B), chlorine (CI), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn) and nickel (Ni). There is increasing interest from the agricultural community in micronutrient fertilization for a variety of reasons, including: soil erosion and long-term cropping have resulted in the removal of micronutrients from soils; increasing crop yields generally leads to greater micronutrient removal rates in grain and other harvested products; and the widespread replacement of micronutrient-rich manures with mineral fertilizers has reduced micronutrient addition from fertilizer sources. Collectively, these factors have led farmers to question whether micronutrient fertilization may now be required to meet the changing demands of crop nutrition. The Tri-State Fertilizer Recommendations state that, in general, soils in Michigan, Indiana, and Ohio have adequate amounts of micronutrients to support crop growth. The only reported micronutrient deficiencies in this region have been with B, Cu, Mn, and Zn. These deficiencies can cause plant abnormalities, reduced growth, and sometimes yield losses. The conditions under which micronutrient deficiencies are most likely to occur have been identified for the Tri-State region.