Foliar Fertilization for Higher Yields

Tanja Folnovic

Agronomy Expert

Micronutrients are essential for plant growth and play an important role in balanced crop nutrition. The importance of micronutrients is equal to macronutrients and a lack of any of them can limit plant growth. Micronutrients that can impact crop yields are boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), and chloride (Cl).

Micronutrients Facts and Deficiency Symptoms

Boron (B) is essential for cell wall formation and rapid growing points within the plant, such as reproductive structures. Symptoms of deficiency vary across crop species and deficiencies are more pronounced during drought periods.


Copper (Cu) activates enzymes and catalyzes reactions in several plant growth processes such as chlorophyll formation, vitamin A production and protein synthesis. With a lack of this element, plant leaves lose turgor and develop a bluish-green shade before become chlorotic and curling.


Iron (Fe) is a component of many enzymes associated with energy transfer, nitrogen reduction and fixation and lignin formation. Iron deficiency causes pale leaf color (chlorosis) with a sharp distinction between green veins and yellow interveinal tissues.


Manganese (Mn) activates several important metabolic reactions and plays a direct role in photosynthesis, accelerates germination and maturity while increasing the availability of phosphorus (P) and calcium (Ca). Deficiency symptoms first appear on younger leaves, with yellow between the veins. A series of brownish-black specks sometimes appear.


Molybdenum (Mo) is vital for the process of symbiotic nitrogen (N) fixation by Rhizobia bacteria in legume root nodules. Deficiencies are relatively rare. Symptoms are yellowing and stunting of the plant and sometimes marginal scorching and cupping or rolling of leaves.


Zinc (Zn) promotes certain metabolic reactions, protein synthesis and growth regulation. Symptoms are the shortening of plant internodes and stunted leaf growth, which appear first on the younger leaves.


Chloride (Cl) participates in stomatal regulation (water stress), osmotic adjustment, and the transport of nutrients such as calcium, magnesium, and potassium within a plant.


Micronutrient Application

The lack of certain micronutrients in the soil and their availability for the plant is affected by the following soil properties:

  • Soil type
  • PH
  • Organic matter content
  • Water and oxygen content
  • Temperature
  • Levels of other elements.


Therefore, appropriate micronutrient fertilization requires soil analyses. Plants also differ in their requirements for certain micronutrients so it’s important to combine plant requirement knowledge with given soil conditions to determine the exact amount of applied fertilizers.

Micronutrient application can be performed as soil fertilization or as a foliar spray. A foliar application has proven to be an excellent method because foliar feeding targets the plants which show the signs of micronutrient deficiency. Foliar feeding can also be an effective management tool to favorably influence pre-reproductive growth stages by compensating for environmentally induced stresses of adverse growing conditions. Foliar micronutrient applications before visible signs of their deficiency can make a crop even better, either by stimulating more vigorous re-growth or maximizing the yield potential growth stage period.

Advantages of foliar sprays rely on much lower application rates than for soil applications, as well as on immediate plant response to the applied nutrient. This method also requires caution due to high salt concentrations of the sprays which can result in leaf burning.

How can Agrivi help?

Agrivi farm management software helps farmers keep track of their entire crop production. Through tasks, farmers can record all their activities in the field, e.g. chemical soil analysis, fertilizers consumption, and whether they are applied to the soil or as foliar sprays and other activities. All data that farmers enter into the system can be automatically analyzed and printed out in the form of reports. In that way, farmers have a complete control over their farm production and the overall farm health.

Boost your farm production by using the Agrivi system.


Text sources: Crop Nutrition || Clemson || MidWest Labs

Image sources: Thompson Limited ||Pioneer||IPNI||MTVernon||Yara||University of Idaho ||Ministry of Agriculture, Food & Rural Affairs||Crop Nutrition||Department of Agriculture and Food||Lotus Export

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