Magnesium Deficiency in Plants

One of the most essential minerals required for healthy plant growth and development is magnesium. Magnesium is the building block of chlorophyll that makes the leaves appear green in color. In the structure of chlorophyll molecule, magnesium is the central atom (C₅₅H₇₂O₅N₄Mg). Chlorophyll is very important for the process of photosynthesis that is, the process for making food and energy within the plants. Thus, magnesium deficiency in plants can lead to may kinds of problems within the plant. Let us discuss some of the symptoms in the next paragraph.

Causes
The deficiency can be due to very wet, acidic or cold root environment. It can also occur due to a high quantity of potassium and calcium in soil as compared to the level of magnesium. The root system becomes limited and the plant being heavy, causes more demand of magnesium than the supply available.

Symptoms
As discussed above, magnesium is one of the important minerals that make up chlorophyll. A magnesium deficiency can lead to many visible symptoms. These symptoms of magnesium deficiency are usually observed in lower and older leaves. Magnesium deficiency leads to chlorosis and necrosis of the leaves. The lower and older leaves develop interveinal chlorosis. The initial symptom of magnesium deficiency is generally a pale green color that is very pronounced in the old or lower leaves. The leaf margins may curve upward and may turn red brown to purple in color in some plants. During the preharvest season, it may lead to leaf drop, weak stalks and long branched roots. The older needles in conifers become yellow in color. The new needles in the lower region may turn yellow in some conifers. Other symptoms include orange-yellow chlorosis on older leaves, the green color on leaves turns 'strings of beads' that look like yellow and green stripes that run parallel to one another. The magnesium deficiency leads to more number of leaves, leaf length and they are wavy and droopy due to the expansion of the angle between leaf sheath and leaf blade.

How to Treat
Magnesium deficiency in plants leads to reduction in yield and stunted growth of plants. It also leads to increase in susceptibility to diseases and finally death of the plant. Magnesium deficiency is very common in tomato plant, potato plant and fruit trees like apples, currants and gooseberries. The reason is high potassium levels that are required for higher yields. But, this potassium causes locking up of magnesium, thus, making it unavailable to plants.

Treating magnesium deficiency is very easy. Plants can take up magnesium through a process called foliar feeding, that can be done by absorbing magnesium through the leaves. So, one needs to take 20g Epsom salts per liter of water and spray it over the plants. Any excess of the solution can be fed to the root system of the plant.

One can use dolomite lime that contains 8% magnesium instead of ordinary lime in rotation. One can even try using mineral kieserite to feed the plant magnesium sulfate through soil. However, make sure you do not over feed both mineral kieserite or dolomite lime to the plant or it will lead to potassium deficiency. Organic options include use of compost cow or turkey manure.

If you observe any of the symptoms of magnesium deficiency in plants, you can try feeding them Epsom salts through foliar feeding. This will help in keeping your plants healthy and prevent them from dying.