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 microelements are involved in this upsurge.

Stages of High Nutrient Demand

Typical examples of such stages are:

• Quick growth of seedlings 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 (increased demand for B and Ca required for pollen-tube development and growth)
• During rapid fruit expansion in many types of fruit crops
• During the bulking-up process in bulb or tuber crops
• During the initiation of lint production in lint crops

Causes of Inadequate Soil Supply

Frequently, these critical growth phases that determine the yield and the quality of the produce coincide with inadequate soil supply, stemming from various situations such as:

• Waterlogged soils that inhibit root respiration and its adequate functioning
• Low soil temperature restricting nutrient uptake by the roots (especially in early spring when higher air temperature supports shoot growth)
• Nematodes infestation.
• Uncontrolled weed population, that severely compete with the growing crop
• Internal bottlenecks 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 meet the crop’s yielding potential (e.g., Ca delivery to developing apple fruits or K delivery to the beginning of lint bolls in cotton plants)

What are the Advantages of Foliar Feeding?

Foliar feeding can be useful under all the above-mentioned cases of necessary intensive mineral nutrition. The major advantage of foliar feeding is that it can address an urgent need within a relatively short time. Therefore it is especially efficient as a preventive — and in some cases curative — treatment. 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 Spray gives Full Control

Foliar sprays give the grower full control regarding the following:

• Application timing can be immediate when the deficiency symptoms are identified so the damage can be corrected before it develops into serious yield loss.
• Application concentration and frequency will optimally address and resolve the deficiency.
• Application during the best weather conditions will provide optimum efficacy.
• The high efficacy offers considerable reduction in the application rate (compared to soil application), without compromising the results, so a marked saving on the fertilizer is achieved and the environmental footprint is minimal.
• The nutrients applied can be tank-mixed with pesticides, achieving a synergic effect and giving additional savings on application costs.
• Foliar feeding can serve as a timely measure to prepare the crops for 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, sulfur, or trace elements — the foliar application can be a stand-alone measure, so that crop requirements can be fully fulfilled before deficiencies can take place. In this way it avoids crop exposure to even subclinical nutrients insufficiency.