• Mineral soils of the Midwest are well equipped to supply most micronutrient needs for high yielding corn and soybeans.
• Soil testing and plant tissue sampling along with root examination and the growing environment provide a better understanding of crop nutrient deficiencies and needs.
• Two possible micronutrients to focus on are boron in corn and molybdenum in soybeans.
• Boron is responsible for grain set and is scarce in the Midwest while molybdenum is necessary for nodulation in soybeans and found in low amounts in Midwest soils. 

In the pursuit of higher crop yields, a renewed interest in micronutrient fertilization has emerged. Most Midwest soils have large quantities of mineral rich rocks and organic matter and contain the micronutrients needed by the crops. The table below illustrates the ranges of micronutrients present in the top six inches of most mineral soils versus the crop needs for different crops at varying yield levels. By design, mineral soils are well equipped to supply ample micronutrients to the growing crop at high yields. Pairing tissue and soil samples is the best way to determine micronutrient needs and ultimately deciding which product best fits the needs.
 

True micronutrient nutrient deficiencies can be caused by several factors.These factors may include too low soil pH, too much or too little soil moisture (nutrients need to be in solution to be taken up and oxygen needs to be present), root abnormalities due to pruning or compaction, soil or air temperature shifts and true soil deficiencies.All these factors alone or in combination can lead to nutrient deficiency symptoms or a hidden deficiency that does not present visual symptoms.Discovering the true cause can solve the problem long term.Unfortunately, deficiency symptoms can be difficult to discern, as they can resemble one another or those caused by environmental factors. Tissue testing paired with soil samples taken from the same area will provide more reliable nutrient deficiency information.

Foliar products currently on the market all share a common carrier, water, which holds the nutrients in solution.A gallon of water can only hold so much dissolved nutrient whether it may be many micronutrients combined or a concentration of only a few (≤ 3 nutrients).For this reason, products containing only a few nutrients have a higher analysis of such nutrients compared to products containing many individual nutrients.Higher analysis fertilizers are more likely to result in a yield response because they deliver a higher dosage of nutrients to the growing crop. If not treating for an identified nutrient deficiency, but simply to enhance yields, choose products containing minerals that are not found in Midwest soils or those found in low amounts. For example, boron containing minerals are scarce in the Midwest and for corn, boron is important for seed/grain formation. With soybeans, a good example is molybdenum which is essential for nodule formation yet found in low amounts in Midwest soils. Nonetheless, with some of these foliar fertilizers, it is still difficult to supply total nutrient needs in a single application.If we are dealing with true soil deficiencies, correction is achieved more efficiently and economically with dry fertilizer products that have a higher nutrient analysis. For more information on foliar product selection or tissue and soil testing contact your local FS crop specialist.