The Eight Micronutrients not to be ignored
Micronutrients are often applied pre-plant but additional applications of chelated fertilizer eight micronutrients may be needed. Micronutrients are often applied pre-plant but additional in season applications of chelated fertilizers eight micronutrients may be needed to address plant micronutrient deficiencies that may occur due to high or low soil pH, plant or environmental issues. Often N, P, or K fertilizers lack sufficient quantities of essential micronutrients to meet plant needs. Synthetic micronutrient fertilizers in the ionic form are available to plants within a limited pH range (pH 6.5 to 7.5). High soil pH (pH>7.5) decreases the availability of copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn). When the soil pH is low, the macronutrients calcium (Ca), magnesium (Mg), and molybdenum (Mo) may be limited. Consequently, soil applications of synthetic micronutrients are particularly challenging and can be problematic especially in sandy soils or when growing crops that have high micronutrient demands. Synthetic and organic chelated micronutrients were developed that are less reactive to soil conditions. These fertilizers can significantly enhance nutrient uptake and improve efficiency of utilization. Application rates of most chelated micronutrients are 0.2 to 1 pound per acre for vegetables, and 0.1 to 0.5 pound per acre for fruits. Foliar application is often more effective.
The type of soil can affect micronutrient availability. Leached sandy soils have low CEC are low in B, Cu, Mn, Mo, and Zn. Quartz is low in Zn. Alluvial soils, weathered acid soils that are subject to leaching, and low organic matter soils all tend to be deficient in micronutrients. High pH soils are low in Fe, Mn, Zn. Acidic soil may be deficient in Mo.
High pH soil often has low bioavailability in micronutrients such Cu, Fe, Mn, and Zn.
Crop susceptibility to micronutrient deficiencies depends on the plant species and cultivar, and environmental conditions.
Inorganic water-soluble micronutrient soil application is often ineffective for correcting
micronutrient disorders (foliar application is recommended).
Chelated micronutrients are less reactive to soil conditions and can enhance nutrient uptake and utilization.
Chelated fertilizers eight micronutrients are fertilizers where the micronutrient ion is surrounded by a larger molecule called a ligand or chelator. Ligands can be natural or synthetic chemicals. These compounds combined with a micronutrient forms a chelated micronutrient. Chelated micronutrients are protected from oxidation, precipitation, and immobilization in certain conditions. These chelates have different effective pH ranges. There are also naturally occurring chelating agents such as amino acids, organic acids, humic and fulvic acids, ligninosulfonates, ligninipolycarboxylates, sugar acids, phenols, polyphosphates, flavonoids, and siderophores. These are functional over a wider pH range, and less toxic to plants. Both synthetic and non synthetic chelates are OMRI permitted.