The Science Behind Micronutrients
Plants need light, heat, water, air, and essential nutrients. These are divided into major elements, secondary elements, and trace elements (micronutrients) for growth.
Table 1
Element Availability in the Soil
Soil chemical and physical properties affect micronutrient availability to plants. pH plays a key role—alkaline soils above pH 7.0 hinder iron absorption, while acidic soils below pH 7.0 limit molybdenum availability, impacting plant health and growth.
| Element | Function in Plant Growth | Function in Crop Production |
|---|---|---|
| Zinc | Activates growth hormone enzymes Enhances chlorophyll production Enhances respiration Transforms carbohydrates | Regulates growth Hasten plant maturity Aids carbohydrate formation Stimulates seed production Influences protein formation Promotes water absorption |
| Boron | Essential in cell wall formation Essential for translocation of sugars & starches Regulates starch production Aids in terminal bud formation Essential in formation of pollen grains & tubes | Essential for seed production Enhances protein production Aids in nodule formation Enhances disease resistance |
| Manganese | Regulates growth hormone supply Acts as a catalyst Activates enzymes Aids in photosynthesis Aids in respiration | Accelerates germination Hastens maturity Regulates uptake of C, Mg, & P |
| Copper | Aids in chlorophyll synthesis Acts as a catalyst Activates enzymes Aids in photosynthesis Aids in respiration | Enhances nitrogen utilization Stimulates protein formation Functions in root metabolism |
| Iron | Essential for respiration Aids in chlorophyll synthesis | Essential for healthy growth |
| Molybdenum | Enzyme catalyst for reducing nitrates to ammonia Converts inorganic P to organic form | Enhances nodule formation Enhances nitrogen fixation Enhances protein formation |
After "Trace Elements in Soils & Crops", N.H. Pizer, ed.