Magnesium for Plants: [Use, Advantages, Excess and Deficiencies]
Magnesium is part of the second most important family of nutrients for plants, along with calcium and sulfur.
Its importance acquires the level of vital, but the amounts required by crops are less than the so-called macronutrients.
This reality causes many growers to be confused about the attention they pay to it, and deficiencies then occur.
If you don’t want that to happen to you, the best thing is to take note of the most outstanding points of this nutrient and that they are just the ones that we present to you here.
What is magnesium?
- Magnesium is a chemical element present in the environment that plays a leading role in plant nutrition.
- However, these are not capable of absorbing magnesium in its pure form, but instead take advantage of it as dissolved magnesium in the soil.
- This action is achieved thanks to two chemical processes: perspiration and diffusion (allows the ions to move to the areas that need it most).
- All this means that concerns about magnesium deficiency are not so common, although there have been cases in this regard.
- Its representation as a chemical element is Mg and its dissolution in the soil is denoted by Mg2+.
What factors influence crop response to magnesium fertilization?
The characteristics of the soil are very important when assessing the possible absorption of magnesium by plants.
For example , it is a nutrient that performs better when soils have a high pH.
It also responds better when crops are located in areas where temperatures are generally low.
Moisture and drainage capacity are also involved, since in very dry soils it is more difficult for magnesium to behave well.
The high presence of other nutrients such as sodium, potassium or calcium also has a direct influence on the fertilization capacity.
What is the magnesium content in the soil?
The amount of magnesium in the soil depends a lot on the characteristics of the minerals that compose it.
When working in soils that are dry, the magnesium level can be set in the range of 120 to 2400 ppm, but not all of it is available.
But if it is a soil that is moist, the concentration drops to a range of 5 to 50 ppm.
Of course, all this is modifiable depending on the soil conditions with respect to other elements such as calcium and where erosion is also involved.
What benefits can a soil rich in magnesium have?
- Magnesium is essential for the development of chlorophyll because it is the content of the central atom of each of its molecules. For this reason, when the levels of magnesium in the soil are correct, or adjusted through fertilization, the plants have a better state of health.
- On the other hand, magnesium is a nutrient that has a direct link with the formation and work process carried out by enzymes.
- Likewise, it plays a determining role in the synthesis of certain proteins , such as xanthophylls and carotenoids.
- In the case of carbohydrates, magnesium prevents excessive transfer between leaves and stems.
What disadvantages does an excess of magnesium have?
A magnesium toxicity in plants can lead to problems related to the absorption of other nutrients.
The most common thing is that the plant misses the opportunity to have the correct levels of calcium and potassium, which are nutrients with a very delicate action.
When this is the case, symptoms could be evidenced as if it were a deficit of any of them, but in reality it is an excess of magnesium.
For this reason, the wisest way to act in the face of this reality is to carry out two conclusive studies: soil and tissue.
The study of soils will allow recognizing the amount of nutrients that are in it and assessing the absorption capacity of plants.
In the case of the study of tissues, it will help to determine exactly how much magnesium is circulating and work based on this.
Of course, as long as the fertilizations are carried out taking care of all the nutrients equally, there is very little chance that excesses will occur.
What crops benefit most from the presence of magnesium in the soil?
The crops that benefit most from good levels of magnesium in the soil are mainly citrus.
In many of them, as is the case with kiwi, detecting the deficiency of this nutrient is something simple.
This is because not only does the chlorosis common in other types of crops occur, but there is also the possibility of developing necrosis.
This is a reality that can manifest itself in the same way in different types of black women.
How do we detect deficiency or lack of magnesium in our crops?
Crops that are deficient in magnesium have the peculiarity of manifesting symptoms in the old leaves first.
This condition is due to the fact that it is a mobile nutrient that moves throughout the structure of the plant.
The first are yellow spots that appear on the leaves and that end up occupying their entire extension, but the veins remain green.
It is a logical condition that responds to the leading role that magnesium has in the formation of chlorophyll.
All this then leads to premature defoliation, even affecting the harvest.
Due to the importance of magnesium in crops, it is always advisable to proceed with a soil study to assess its impact on them.
In this way, it will be possible to take the pertinent measures in the event of symptoms of instability of normal levels, either due to excess or deficiency.
In the case of fertilization, the most appropriate thing is to use micronutrient fertilizers that will help all levels to remain stable.