Foliar Application of Magnesium: Need to Knows

Foliar application, magnesium, commercial crops, roots shoots and fruits, biomin

It is widely known that Magnesium is fundamental to the growth of every crop and is required at every stage of the phenological cycle. It is a vital nutrient responsible for the process of photosynthesis, and every metabolic reaction within a plant, so it is essential that it is well absorbed by the plant. 

Magnesium may not have any obvious ‘positive effects’ when added to crops, apart from leaf symptom change. But, even a small Magnesium deficiency can be detrimental to your existing crops and production. Ensure that Magnesium is being readily applied to your crops (via the leaf), in a manner that they are readily absorbing it. 

For foliar applications to be successful, the product must first and foremost be 100% soluble to produce immediate effects on plants.

Why Choose Foliar Application for Magnesium? 

Foliar application is an excellent method to entice crops into absorbing nutrients quickly, as root systems and soil chemistry are often less than perfect.

Unfortunately, growers can be quick to dismiss foliar application methods based on a lack of information and price alone, rather than firstly establishing its effectiveness. Generally, foliar fed plants intake the nutrients through their stomata allowing nutrient deficiencies to begin to correct. The time taken for the mineral nutrient levels to correct depends further on the formulation of the product.

When the symptoms of Magnesium deficiencies are first noticed, typically Magnesium sulfates (such as Epsom salts) are used to treat the condition. Symptoms of a Magnesium deficiency include chlorosis of the leaves, fruit drop, or abortion.

When applied directly to the soil, the Magnesium and other micronutrients in Epsom salt treatments commonly react with the other chemicals that exist there. This causes the supplemental Magnesium to become insoluble in water. As plants use water to source their nutrient intake, once a supplement becomes insoluble in water, the plant no longer has the ability to absorb it, soil treatment is slow and less effective when a quick turnaround of deficiency is required to keep crops at optimum. 

Remember to Apply Magnesium All Year Round

Magnesium is often used as an adjunctive measure to correct symptoms of a deficiency, rather than as a vital nutrient that crops are regularly supplemented with. A common misconception at the end of the growing season is that Magnesium deficiency symptoms are simply the crop nearing the end of its growing and production cycle.

This is when Magnesium deficiencies become problematic. The crop may not be performing at optimum, which can delay ripening. Once the fruit ripens or has been picked, many growers forget about applying Magnesium and leave the plants, as they aren’t actively fertilising for produce. This worsens any deficiencies, and in turn, it can affect the following year’s crop; as Magnesium levels deplete further and as the crop prepares for another growing year, bud initiation is affected. Bud initiation is reliant on the plant having adequate mineral levels, meaning any existing deficiencies are extended to affect crops during the season to follow.

It is important to provide crops with soil supplementation, and equally important to provide efficient and effective foliar applications; this ensures that plants photosynthesize at optimum for commercial production. If only soil amendments are applied, the Magnesium availability will be less effective on the crop. When inferior foliar products such as oxides, or products with low or limited solubility are applied, there is a cost to production.

When a product doesn’t work, it is expensive, right?

Despite having an initial lower cost, less effective products may be dearer in the long run. They can become expensive not only to your profit margin but also to crop health or even your own health. Some commercial products have warning labels denoting potential side effects including: 

  • Suspected of damaging fertility or the unborn child.
  • May cause long-lasting harmful effects to aquatic life.
  • Causes serious eye damage.
  • May cause damage to the blood system through prolonged or repeated exposure.

Glycine Chelation (Biomin Technology)

Let’s talk science … again. If you’ve reached this far I know you’re into the science part too. So here goes…

Glycine chelation is a nutritional formulation that has come to gain popularity within the last decade. Providing superior results to its predecessors, including Sulphates and EDTA chelates, Glycine chelation technology allows for the full absorption of a nutrient by the plant. A patented process, in Glycine chelation every metal ion is bonded with two Glycine, which is the smallest amino acid. The plant recognises the Glycine chelated molecule as proteinaceous, causing it to distribute the formulation rapidly and systemically to core growing points such as fruits, buds and flowers.

Glycine chelated products can be applied to the soil and by foliar application. Foliar application has proven to be the most effective to overcome deficiencies fast.  Inferior foliar-applied products may sit on the leaf rather than entering into the plant’s system, further complicating any existing deficiencies. Those products chelated with large synthetic molecules, have access via the stomata, however, can often become stuck in the plant as the synthetic chelate; rendering them unable to be utilised or assimilated by the plant, causing the initial reason to chelate a mineral (to remove its charge), ineffective.

Glycine is the smallest of the amino acids, creating a smaller final product when used to chelate a metal. It can easily enter through the stomata of a plant, and also permeate through plant parts; allowing it to move systemically via the phloem and the xylem. The Glycine chelate itself is utilised completely by the plant.  

Check out our Glycine Chelated BIOMIN Magnesium product here.

For more information contact Molly at