The Benefits of Foliar Feeding

During their normal seasonal development, most crops encounter stages of high nutrient demand. Generally a whole group of macro-, meso- and micro elements are involved in this upsurge. Typical examples of such stages are:

• Quick growth of seedling after germination in annual crops
• During tillering and grain filling in cereals
• Intensive shoot growth at early spring in all perennial crops
• During flowering and fruit-set in deciduous crops (there is an increased demand for B and Ca, required for pollen-tube development and growth).
• During rapid fruit expansion in many types of fruit crops
• During bulking-up process in bulb or tuber crops
• During the initiation of the lint production in lint crops
  
  Frequently, these critical growth phases that determine the yield and the quality of the produce coincide with inadequate soil supply that stems from various situations such as:
  
  
• Waterlogged soils that inhibit roots' respiration and their adequate functioning.
• Low soil temperature restricts nutrient uptake by the roots (especially in early-spring when higher air temperature supports shoot growth)
• Nematodes infestation.
• Uncontrolled weeds population, that severely compete with the growing crop.
• Internal bottle-necks within the plant, due to, e.g. shoot-to-root competition, rendering specific organs unable to absorb the necessary nutrients at a high enough pace to realize crop's yielding potential (examples Ca delivery to developing apple fruits, or K delivery to the initials of lint bolls in cotton plants).

Foliar feeding can be very instrumental under all above-mentioned cases of necessary intensive mineral nutrition. The big advantage of foliar feeding is that they can address an urgent need within a relatively short time. They are therefore, especially efficient as a preventive and in some cases curative treatments.
Foliar fertilization of crops offer specific advantages over soil-applied fertilizers, because the nutrients are applied and taken-up directly by their target organs, providing a specific and rapid response. Often the soil with its chemical, physical and biological complexity acts as a barrier and a buffering medium.

Foliar sprays gives the grower full control regarding:

• Application timing that can be immediate when the deficiency symptoms are identified, hence, they enable correcting the damage before it develops to serious yield loss.
• Application concentration and frequency that will optimally address and resolve the deficiency.
• Application during the best weather conditions that will provide optimum efficacy.
• The high efficacy offers considerable reduction of the application rate (as compared to soil application), without compromising the results, thus a marked saving on the fertilizer is achieved and a minimal environmental foot-print takes place.
• The nutrients applied can be tank-mixed with pesticides, thereby achieving a synergic effect and additional saving on application costs.
• Foliar feeding can serve as a timely measure to prepare the crops to expected biotic or abiotic stress, such as chill, drought, or heat stresses.

Foliar feeding is not generally intended to replace soil or fertigation applications, but to complement them. But when just small application rates are required, such as in the case of Phosphorus, Calcium, Magnesium, Sulphur or trace elements, the foliar application can be a stand-alone measure, by which crops' requirements can be fully fulfilled, before deficiencies can take place. In this way it avoids crops exposure to even sub-clinical nutrients insufficiency.

By ICL Specialty Fertilizers
Agronomist team