Questions are often raised about the relative importance of micronutrients in crop production. It has been well established that optimum yields generally are not possible without N, P and K fertilizers, and secondary nutrients to a lesser extent. Most growers and dealers follow the recommended rates and methods of application to achieve top yields, but they may not consider that one or more micronutrients may also be limiting their yields.
Micronutrients are needed in small amounts by corn, and if deficiencies occur, yields could be limited. Micronutrients are those elements essential for plant growth, but required in much smaller amounts than N, P and K. Micronutrients include boron, copper, iron, manganese, molybdenum, zinc and chloride.
Micronutrient deficiencies are verified in many soils through soil testing and plant analyses. Soil tests should be included in all micronutrient fertilization programs. The University of Arkansas Soil Testing Laboratory routinely tests soils for iron, manganese, zinc and copper. Molybdenum should not be deficient in corn under most circumstances. Iron, manganese, zinc, copper and boron are adequate in most soils. However, low levels and possible deficiencies of some of these could occur on leached, sandy soils of low CEC and on medium-textured soils that have an alkaline (high) pH or that have been over-limed. Plant analyses give an indication of the micronutrient status of crops during the growing season.
Micronutrient recommendations are based on soil and plant tissue analyses, crop species and expected yield, management level, and research results. Because recommended rates are usually low, most micronutrients are applied with NPK fertilizers, but foliar sprays are also frequently applied. Choice of micronutrient source depends on the method of application, compatibility with the NPK fertilizer, convenience of application, and the relative agronomic effectiveness and cost per unit of micronutrient.
Remember! Check your micronutrient levels before you apply your herbicide. Most all of them can be added with this application if needed.