- Magnesium: Why is it important for plant growth?
- Fixing Magnesium Deficiency in Plants: How Magnesium Affects Plant Growth
- How Do Plants Use Magnesium?
- Magnesium Deficiency in Plants
- Providing Magnesium for Plants
- Chapter 15. Magnesium
- Magnesium In The Plant
- Magnesium In The Soil
- Magnesium Fertilizers
- Magnesium: Essential for a plant’s health, and ours
- shop this post
- Why is Magnesium Important?
- Signs of Magnesium Deficiency
- How Much Magnesium Do You Need?
- Best Sources of Magnesium
- How to Get More Magnesium in Your Diet
- Got Magnesium-Related Questions?
- The Benefits of Chlorophyll
- Magnesium in Plants and Soil
- Magnesium Pools in Soils
- Magnesium Uptake by Plants
- Magnesium Availability and Uptake
- Magnesium Deficiencies
- SMART Fertilizer Management Software – Innovative Solution
- Magnesium Deficiency In Plants
- The Role of Magnesium in Plants.
- Symptoms of a Magnesium Deficiency
- Correcting Magnesium Deficiency
- Additional Suggestions
Characteristics and occurrence
Magnesium (Mg) deficiency may result either from low magnesium content in the soil or from an overabundance of potassium or calcium which inhibit magnesium uptake by the crop. Therefore, the disorder is most likely to occur on sandy soils with low cation exchange capacity (CEC), on volcanic ash soils of high potassium status, or on some calcareous soils. Overfertilisation with potassium may also induce magnesium deficiency. In strongly acidic soils, magnesium deficiency may be induced by the presence of toxic concentrations of aluminium in the root environment, which inhibit magnesium uptake by the plant (see Aluminium Toxicity).
A magnesium-deficient crop will tend to have a pale overall colour. The earliest specific symptom of magnesium deficiency is an interveinal chlorosis of older leaves. Typically, the main veins retain a relatively broad margin of dark green tissue, but the minor veins are less well defined, resulting in radial bands of pale tissue between the main veins. However, in some cultivars the chlorosis is more mottled, composed of isolated patches, or the veins retain little green margin, and appear as a green network on a generally pale leaf. Chlorosis first appears on the oldest leaves, but may spread to quite young leaves. It may be accompanied by upward or downward curling of the leaf margins, or a wilty drooping of the leaf blades.
Purple or red-brown pigment may appear on older leaves in conjunction with chlorosis. Most commonly, pigmentation affects the upper surface of interveinal patches near the leaf tip and margins, but in some cultivars the veins under the leaf may become red.
Chlorosis generally progresses to yellowing and necrosis of the oldest leaves. Leaves may become entirely yellow and wilted before browning off, or necrosis may develop on interveinal and marginal tissues without prior chlorosis. Most commonly, localised yellowing precedes necrotic lesions, which spread from interveinal zones.
The vines of magnesium-deficient plants may become thin and twining, with lengthened internodes, a response similar to etiolation.
Possible confusion with other symptoms
Potassium deficiency may also produce interveinal necrotic lesions surrounded by chlorosis in oldest leaves. However, in the case of magnesium deficiency, necrosis is usually in a more regular pattern around the leaf, confined to interveinal and marginal zones. In addition, the senescing leaves are generally wilted, and the necrotic tissue is usually paler and remains soft.
Diagnostic soil and plant tissue tests
The critical concentration for magnesium in sweetpotato leaves is not yet well defined, as various sources of information are not in good agreement. In particular, estimates based on solution- or sand-culture experiments tend to be lower than those observed in the field. In solution culture experiments, a critical concentration (leaf blades 7-9 at 4 weeks) of 0.12% magnesium was estimated for magnesium deficiency, while healthy plants were observed to contain 0.15-0.35% magnesium. This agrees well with reports from sand culture studies. However, symptoms observed in field crops in Uganda and Australia have been associated with concentrations in the index leaves of 0.29-0.37% magnesium and in USA 0.40% magnesium has been reported in an magnesium-deficient crop, suggesting a critical concentration greater than 0.40%.
Soil tests have not been calibrated for sweetpotato response to magnesium. For other field crops, neutral 1 M ammonium acetate-exchangeable magnesium levels of greater than 100-200 mg magnesium/kg are generally considered adequate. European standards recommend consideration of soil test K levels also, with a K/magnesium ratio of less than 5, on a weight-of-element basis, being desirable.
Magnesium deficiency may be corrected by incorporation of dolomitic lime or magnesium oxide into acid soils (20-50 kg magnesium/ha), or by band application of kieserite or fertiliser-grade magnesium sulfate (10-40 kg magnesium/ha). As magnesium sulfate is the most soluble of these sources, it is the preferred source where it is necessary to correct an observed magnesium deficiency in an established crop, although it is often more expensive than other sources. If top-dressing of the established crop is difficult, magnesium sulfate may be applied as a foliar spray or by fertigation.
Bolle-Jones, E.W. and Ismunadji, M. 1963. Mineral deficiency symptoms of the sweet potato. Empire Journal of Experimental Agriculture 31, 60-64.
Edmond, J.B. and Sefick, H.J. 1938. A description of certain nutrient deficiency symptoms of the Porto Rico sweetpotato. Proceedings of the American Society for Horticultural Science 36, 544-549.
Reuter, D.J. and Robinson, J.B. (eds.) 1986. Plant Analysis. An interpretation manual. Inkata Press, Melbourne.
Spence, J.A. and Ahmad, N. 1967. Plant nutrient deficiencies and related tissue composition of the sweet potato. Agronomy Journal 59, 59-62.
Contributed by: Jane O’Sullivan
Magnesium: Why is it important for plant growth?
What is Magnesium?
Soil nutrients come in three basic categories: macro, meso and micro elements depending on the quantity in which the plants need them. Magnesium (Mg) is an essential meso nutrient, along with calcium (Ca) and sulfur (S).
Magnesium is a very mobile element that is important for plant growth and development. Its availability in soil depends on multiple factors: the source rock material, the degree of weathering, local climate and the specific agricultural system and its management practices, such as crop type, cropping intensity and rotation, and fertilization practices. Therefore, the amount of magnesium can vary highly depending on the soil type. Low amounts of Mg can be expected in tropical and sandy soils, while soils close to the sea marshland, peat soils, saline soils and generally soils with high clay content tend to have higher amounts of magnesium.
How do plants use Magnesium?
Magnesium is an essential element through the whole growth period of a plant. Magnesium fulfills several functions within the plant; it is a central component of chlorophyll which is supporting the function to absorb sunlight during photosynthesis. Magnesium acts as a phosphorus carrier in plants and is essential for phosphate metabolism.
Furthermore, it is also needed for cell division and protein formation, activation of several enzyme systems and is essential component for plant respiration. In short, without magnesium, chlorophyll cannot capture sun energy for photosynthesis and the important metabolic functions related to carbohydrates and cell membrane stabilization cannot be performed by the plant.
What are the signs of magnesium deficiencies?
Magnesium deficiency commonly occurs in intensively used agricultural soils, but it can also be caused by weathering of soil. It is often seen in sandy, strongly leached and acid soils.
It is not easy to recognize Mg deficiency based on the symptoms. Due to its mobility within the plant, Mg deficiency symptoms will appear on the lower and older leaves first, before the symptoms become visible on the younger leaves. Common deficiency symptoms include:
- slow growth and leaves to turn yellow, especially on the outer edges, which then develop interveinal chlorosis
- newly growing leaves may become yellow with dark spots
- purple or reddish spots on the leaves
The visibility of symptoms is also often related to the amount of light the leaves or plant is exposed to. Plant or leaves exposed to high light intensity will show more symptoms than others.
Magnesium and its importance in crop production and agriculture has been overlooked for some time, even though it is an essential element for plant growth and development. This is due to the fact that it is difficult to detect latent Mg deficiency. The deficiency is often not directly visible but still negatively affects crop growth. Only acute deficiency, when it is too late for crop yield, shows visible signs like interveinal chlorosis and growth reduction.
Why is it important to know the Mg content in the soil?
In contrast to other cations like K, Ca and NH4, Mg is relatively mobile in soils. Especially because the importance of Mg in soil and ultimately crop production has been overlooked and Mg neglected in fertilization practices, Mg can be deficient in soils used in intensive crop production systems.
Furthermore, magnesium is often subject to leaching in considerable amounts especially during autumn and winter month with heavy rains. Magnesium leaching is also influenced by soil acidity, Ca concentration (liming) and Cation Exchange Capacity (CEC) affected by organic matter and clay %. This further demonstrates the necessity of soil testing to know not only the Mg content before the next cropping season but also other parameters that influence the Mg availability for plants.
How does AgroCares technology relate to this?
AgroCares can provide information about the exchangeable magnesium and total magnesium in the soil with the Lab-in-a-Box (LiaB). Exchangeable magnesium is one of the most important fractions to determine whether magnesium is available or not available for the plant. Agrocares LiaB can give crop specific recommendations for magnesium ensuring that the right amount of it is applied to the soil to achieve the desired crop yield. The recommendations include information about when and how magnesium fertilization should be applied. Additionally, LiaB can provide simply the analysis results for exchangeable magnesium which can then be used to create individual fertilizer recommendations.
Would you like to learn more about Lab-in-a-Box and its possibilities? Which the product page or contact us for more information!
Fixing Magnesium Deficiency in Plants: How Magnesium Affects Plant Growth
Technically, magnesium is a metallic chemical element which is vital for human and plant life. Magnesium is one of thirteen mineral nutrients that come from soil, and when dissolved in water, is absorbed through the plant’s roots. Sometimes there are not enough mineral nutrients in soil and it is necessary to fertilize in order to replenish these elements and provide additional magnesium for plants.
How Do Plants Use Magnesium?
Magnesium is the powerhouse behind photosynthesis in plants. Without magnesium, chlorophyll cannot capture sun energy needed for photosynthesis. In short, magnesium is required to give leaves their green color. Magnesium in plants is located in the enzymes, in the heart of the chlorophyll molecule. Magnesium is also used by plants for the metabolism of carbohydrates and in the cell membrane stabilization.
Magnesium Deficiency in Plants
The role of magnesium is vital to plant growth and health. Magnesium deficiency in plants is common where soil is not rich in organic matter or is very light.
Heavy rains can cause a deficiency to occur by leaching magnesium out of sandy or acidic soil. In addition, if soil contains high amounts of potassium, plants may absorb this instead of magnesium, leading to a deficiency.
Plants that are suffering from a lack of magnesium will display identifiable characteristics. Magnesium deficiency appears on older leaves first as they become yellow between the veins and around the edges. Purple, red or brown may also appear on the leaves. Eventually, if left unchecked, the leaf and the plant will die.
Providing Magnesium for Plants
Providing magnesium for plants begins with annual applications of rich, organic compost. Compost conserves moisture and helps keep nutrients form leaching out during heavy rainfall. Organic compost is also rich in magnesium and will provide an abundant source for plants.
Chemical leaf sprays are also used as a temporary solution to provide magnesium.
Some people have also found success with using Epsom salts in the garden to help plants take up nutrients easier and improve magnesium deficient soil.
Chapter 15. Magnesium
Magnesium is a constituent of chlorophyll. It is also active in the metabolism of phosphorus. A deficiency rarely affects yield but can reduce the nutritional quality of crops.
Cation exchange is the only means of holding magnesium against losses in the soil.
Fertilizing for magnesium in soils naturally low in magnesium requires an inorganic amendment. It is especially difficult if both calcium and potassium are high.
Table 24. Fertilizers For Supplying Magnesium lists the magnesium content of typical fertilizers.
Magnesium In The Plant
Magnesium puts the Green in green plants. It is the only metal which is a constituent of chlorophyll. Chlorophyll is identical to the hemoglobin in blood, except that chlorophyll contains magnesium instead of iron. It is not too excessive to claim that a lack of magnesium produces anemic plants.
Only about 20% of the magnesium in plants, however, is in chlorophyll. The rest functions as a regulator for various metabolic processes. Magnesium is necessary in every operation involving phosphorus; an apparent phosphorus deficiency can sometimes be tempered with magnesium fertilizer. In addition, magnesium influences nitrogen metabolism and is important in the assimilation of carbon dioxide during photosynthesis.
Magnesium and sulfur are the most neglected of the major nutrients, sulfur no doubt because until recently fertilizers contained enough to satisfy plant requirements. In the case of magnesium, nothing short of a gross deficiency seems to affect yields, unless phosphorus is also low.
This masks, however, the effect of magnesium on the nutritional value of crops. Like sulfur, some amino acids contain magnesium; a deficiency will result in an insufficient supply of true proteins requiring those amino acids and an enlarged pool of free amino acids. The missing proteins reduce the quality of produce for both animal and human consumption.
An antagonistic relationship exists among calcium, magnesium and potassium: all three are cations, and the total absorption of cations by plant roots is limited. Plants, however, have a built-in preference for potassium, the soil supply of which is usually adequate to excessive; and calcium is the predominant component of lime. Magnesium is rarely prominent in a soil amendment, and it often ends up short.
There are no characteristic symptoms of a mild magnesium deficiency – a moderate deficiency may result in a yellowing of leaves between the leaf veins – perhaps only an awareness that the plant is not functioning or producing well. Owing to the reduced assimilation of carbon dioxide, growth is stunted, and ripe fruit lacks sweetness. A deficiency retards phosphorus metabolism and protein production.
Magnesium In The Soil
Magnesium behaves much like calcium in the soil. Both are easily leached in humid areas. Conservation of either depends upon the cation exchange properties of the soil.
The age of the soil and weather conditions influence the cation exchange capacity and the presence of magnesium. Owing to the particular clays in many of the young unweathered western soils, the exchange capacity is usually high. In addition, these soils are also high in magnesium. Not all soils in the west are so blessed, but many of them are natural cation reserves and very well filled.
Older, weathered soils in the humid areas of the east and south, however, are less favored. Except for some soils (in Pennsylvania for example), old soils are especially leached of magnesium, and the clays are poor at contributing to the cation exchange capacity. Organic matter is the predominant influence in determining the exchange capacity. Moreover leaching has left these soils acid, and so the exchange reservoir is filled mainly with non-nutritive acid ions.
The following discussion is relevant only where magnesium is low in the soil. Cation balance is not critical where magnesium is moderate to high, unless it begins to approach levels of the order of 70% of the cation reservoir. And where that extreme situation does exist, I have no help to offer.
Almost all soils in humid areas must be limed periodically. The question then arises, what kind of lime is appropriate. It is reasonable to suppose that a balance should exist among the nutrient cations (calcium, magnesium and potassium).
We do know that excessive potassium can lead to a magnesium deficiency and sometimes a calcium deficiency. An excess of calcium has been responsible for deficiencies in both magnesium and potassium. Experiments have led to the conclusion that, for many crops, the soil should contain at least as many magnesium ions as potassium ions1.
Recently, one criterion for cation balance has been adopted by several soil testing laboratories. According to this criterion, 60-70% of the soil reservoir should be filled with calcium, 10-15% with magnesium, 2-5% with potassium and the remainder with acid ions. Within the last few years, however, the hypothesis of cation balance has been challenged, and experiments have shown that yields are substantially independent of these or any similar guidelines based upon the percentage of ions in the cation reservoir. A controversy still exists on the issue.
One issue is that experiments used to test this criterion are set up so that all other nutrients are well supplied. This masks the relationship between phosphorus and magnesium, because magnesium has less importance if phosphorus is high.
Furthermore, tests based on yield alone is an additional bias against magnesium, which is more important in determining the quality of a harvest rather than its quantity2.
The concept of an appropriate distribution of the nutrients which make up the cation reservoir does have two uses. One is to determine the amount of lime required to raise the pH to a desired point, and the other is to set a minimum level for magnesium. Tentatively, the following may be a useful guide: In terms of lbs/acre, the soil should contain at least one tenth as much magnesium as calcium, and at least 60% as much magnesium as potassium 3.
A guideline for setting minimum levels of potassium should take into account the need to balance nitrogen but not so high as to overwhelm magnesium or calcium. The proper nitrogen/potassium balance is determined by the crop requirements; tables 3. Estimated Fertilizer Requirements – Field Crops – 5. Average Nutrient Requirements For Vegetables may be useful for the purpose.
In practice, a conflict between balancing nitrogen and not overpowering magnesium should occur only with a depleted, weathered soil possessing a low organic content; such a soil has a low cation exchange capacity and little ability to store magnesium. In order to preserve the proper magnesium/potassium balance in that case, potassium and consequently nitrogen should be limited; which of course affects the yield. However, table 2. Effects Of A Nutrient Disorder On Crop Quality has examples where heavy fertilization with potassium fertilizers without taking into account the necessity of balancing magnesium and calcium affects the appearance of fruit and vegetable crops.
One reason why the relationship among calcium, magnesium and potassium can be so loose is that, within a wide range of values, excessive magnesium is not a concern. Some soils in California have enough magnesium to fill 40% of the cation reserve and yet produce high yields. To be sure, soils with 70% magnesium can not grow crops, but this still leaves room for variation.
Table 24. Fertilizers For Supplying Magnesium lists the magnesium content of typical organic materials and of the principal fertilizers.
Most organic residues have a small but significant amount of magnesium. About 20 – 30 lbs of magnesium/acre can be supplied by fresh poultry manure spread at a rate of 5 tons/acre and the other manures at 10 tons/acre, or a hay mulch made from bales split up into one-inch layers4. This quantity is enough to supply most crops with sufficient magnesium, although some of the magnesium is likely to be lost by leaching. Compost is an excellent source of magnesium, but not enough information is available to indicate typical amounts.
These residues, however, would add a much greater amount of potassium than magnesium. For example, table 24. Fertilizers For Supplying Magnesium suggests an application of 10 tons/acre of non-poultry manure for about 25 lbs of magnesium. However, table 9. Nutrient Content of Manure shows that nonpoultry manure may contain about 10 lbs of potash/ton; so a rate of 10 tons/acre will add 100 lbs of potash, or four times as much potassium as magnesium. Similarly, a hay mulch will add more than ten times as much potassium as magnesium.
Soybean meal (and probably cottonseed meal and seedcake residues) is a good source of magnesium, but it is likely to contain about four times as much potassium as magnesium. Only poultry manure seems to have a reasonable balance, supplying a bit less than twice as much potassium as magnesium.
Most organic residues are better sources of magnesium than of calcium, but they are not an ideal magnesium fertilizer. If a soil has a low ratio of magnesium to potassium, most organic residues will not improve the ratio, and they may make it worse.
The two most common inorganic fertilizers for magnesium are dolomitic limestone and sulfate of potash magnesia. Dolomitic limestone is the cheapest of inorganic magnesium fertilizers and is the logical choice for acid soils. But sulfate of potash magnesia is useful if potassium is also low.
Often, however, owing perhaps to a mistake in fertilizer usage, a soil may be high in both calcium and potassium, in which case neither of these amendments is appropriate. The two alternatives are epsom salts and magnesia, both soluble. Neither one is satisfactory, for reasons to be given presently, and they are both customarily used in small quantities, perhaps enough for temporary relief of a magnesium deficiency, but not enough to raise the soil reserve. They are best used only in an emergency or after a test trial to determine their effectiveness.
Epsom salts are a natural mineral, although they are also synthesized. Magnesia is usually made by heating magnesite, a naturally occurring magnesium carbonate, to drive off the carbon dioxide, a process similar to that used in the production of burned lime from calcitic limestone. Magnesia is a common constituent of commercial fertilizers fortified with magnesium.
Epsom salts are expensive and impractical to spread in large amounts; quantities of the order of 150-200 lbs/acre are common, but this supplies only a small amount of magnesium. An alternative is to apply epsom salts as a foliar spray several times during the season, at a rate of about 10 – 15 lbs/100 gallons of water, saturating the plants .
Magnesia is cheaper to add in larger quantities, but it will raise the pH. Spreading magnesia might be feasible in small amounts where a slight pH rise is tolerable. The maximum permissable rate of application varies with individual soils, because it depends upon the permissable rise in the pH and the cation exchange capacity. The liming value of magnesia is calculated in appendix C. Acid and Basic Fertilizers – magnesia . Another disadvantage to magnesia is that it is a dehydrating agent and might affect soil life.
In summary, supplying sufficient magnesium while maintaining a good balance with calcium and potassium is difficult in magnesium-deficient soils with a low organic content. It requires sufficient planning.
1 that is, the total number in solution and in the cation exchange reservoir
2 This argument depends on a definition of quality to include not only the appearance of produce but also the nutritional value.
3 These suggestions are based upon the following reasoning: The conversion factor between the pounds of a nutrient and the number of atoms, or ions, varies with the nutrient. So a magnesium/calcium ratio of 10/100 in terms of lbs/acre is equivalent to a ratio of 10/60 in terms of ions/acre. This idealized 10/60 ratio is an extrapolation from the earlier criterion (10% magnesium and 60% calcium). Similarly, a magnesium/potassium ratio of 60/100 in terms of lbs/acre is equivalent to a ratio of 1 in terms of ions/acre. As noted earlier, the relation between magnesium and potassium does have an experimental basis for some crops.
The term ions/acre is not a standard unit of measure. The customary measure in soil science is milliequivalents/100 grams of soil, abbreviated as meq/100 g (although this unit is now being replaced in some technical journals). Exchangeable cations and the cation exchange capacity are reported in terms of this unit. The conversion between lbs/acre and meq/100 g is given by the formula, (lbs/A) = F * (meq/100 g), where F = 20 * (FW)/(V) (FW is the formula weight, and V is the valence of the ion). The idealized magnesium/calcium ratio stated above is the same in either case, but a magnesium/potassium ratio of 1/1 in terms of ions/acre is 2/1 in terms of meq/100 g.
4 Assuming a bale size 11 by 18 by 30 inches weighing 35 lbs, we would find that one bale split up into one-inch layers will occupy a space of about 56 sq. ft. Thus 774 bales would be required to cover one acre, and the total weight of the bales would be about 13-1/2 tons. If each ton supplies two lbs of magnesium, the mulch would add about 27 lbs of magnesium/acre.
Magnesium: Essential for a plant’s health, and ours
“Magnesium (Mg) is needed for more than 300 biochemical reactions in the body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady, supports a healthy immune system, and keeps bones strong. Magnesium also helps regulate blood sugar levels, promotes normal blood pressure, and is known to be involved in energy metabolism and protein synthesis. There is an increased interest in the role of magnesium in preventing and managing disorders such as hypertension, cardiovascular disease, and diabetes.”
Where do WE get magnesium? Foods such as green leafy vegetables, some legumes, nuts, seeds and unrefined grains are good sources. However, if those plants do not get enough magnesium, neither do we. Without enough magnesium, plants often develop some yellowing in their older leaves between the veins. Magnesium is essential for photosynthesis, and helps activate plant enzymes needed for growth. Animals have a need for more magnesium than plants, so a plant magnesium deficiency often shows up first in the animals, especially those that graze or forage.
|Montmorillonite clay soil||Serpentine||Vermiculite|
Where does magnesium come from? Magnesium is an abundant alkaline element in the earth’s crust, occurring naturally in several minerals like dolomite, vermiculite and clay soils like montmorillonite. It is the third most dissolved element in sea water, and seafoods are among the foods highest in magnesium. Alkaline soils and humus-rich soils generally contain more magnesium that acidic soils. Magnesium found in the form of magnesium ions (Mg2+) in the soil (in solution or bound to soil particles) is the most important for exchangeable magnesium. However, magnesium ions are at risk of leaching along with nitrates and calcium.
Other plant sources for magnesium are organic materials (compost), animal dung and plant material. The more magnesium taken up by the old plant material, the more will be available again for new crops. Cation Exchange Capacity, called CEC, (see http://www.spectrumanalytic.com/support/library/ff/CEC_BpH_and_percent_sat.htm) affects the potential for plants to take up magnesium. Soils with a high CEC tend to hold more magnesium. However, if there are also high levels of N and K (nitrogen and potassium) in the soil, less Mg will be available. You can add magnesium with serpentine superphosphate (a slow-release magnesium), dolomite (a calcium-magnesium limestone), and calcinated magnesite.
You can also add magnesium by using Epsom salts, which is very water-soluble (thus readily available to plants) and best used as a foliar spray to prevent leaching. Epsom salts is a magnesium sulfate, extracted from the mineral Epsomate, and naturally occurs in water. The name Epsom comes from the town in England (Epsom) where water was first boiled to release these minerals. The advantage of magnesium sulfate over other magnesium soil amendments (such as dolomitic lime) is its high solubility.
Some plants, notably roses, tomatoes, potatoes and peppers require a soil high in magnesium. If you grow these, you should have a soil test done to determine magnesium levels, especially available magnesium, and then choose your magnesium amendment(s) carefully for optimal uptake.
Feed your plants with the right nutrition and they will feed you!
Click on these to take you to my other articles on soil and nutrients:
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Here are 12 excellent food sources of magnesium! We’re uncovering the best sources of magnesium, why magnesium is important and how to add more to your diet.
We’re back with another nutrition article and it’s focused on magnesium! So far we’ve tackled the ins and outs of fiber, as well as vegan sources of calcium and plant-based protein. I figured we might as well make our way down the list!
Today we’re going to talk all about magnesium. We cover why magnesium is important, signs you might be magnesium deficient, as well as some excellent food sources of magnesium
Think of this as a sort of 101 type article. A who, what, where and why. These are super fun for me to write, so let me know what other nutrients you want to chat about next!
Why is Magnesium Important?
Magnesium is a macro-mineral and is critical in the body. It is involved in hundreds of enzyme reactions which are important for the production of energy as well as heart health. It’s also been shown to help prevent coronary artery spasms which can lead to heart attacks.
Magnesium is also considered the “anti-stress” mineral. It’s a natural tranquilizer of sorts by helping to relax our muscles. It also smooth the muscles in our digestive tract. It’s even been turned into powdered drinks that you can take before bed to help with sleep.
Magnesium needs other minerals to function properly, the most important being calcium. When it’s balanced with calcium it can help prevent high blood pressure. Magnesium has also been shown to help things like anxiety, muscle and menstrual cramps, insomnia and even kidney stones.
Signs of Magnesium Deficiency
Most people who are eating a healthy diet full of fruits, veggies, grains, and legumes are not magnesium deficient. However, if you’re unsure, there are a few signs to look out for.
I want to preface this again by saying, a) I’m not a medical professional and I only ever share what works for me, and b) work with a medical professional before you begin supplementing and/or making any major changes to your diet.
Magnesium deficiency can have symptoms like:
- Loss of appetite
Again, don’t make any change without consulting your healthcare provider first!
How Much Magnesium Do You Need?
Just like any nutrient, the amount of magnesium that you need is different for every individual. However, men typically need more than women. Here are the daily magnesium recommendations for both men and women:
- Women: 310 – 320mg
- Men: 400 – 420mg
You can mostly get magnesium from the food you’re eating. I definitely recommend working with your holistic practitioner to get a blood test done first. They’ll be able to see where your levels are in comparison to the normal range for your body type (height, weight, gender, age, etc.).
From there you can make the decision to add more magnesium-rich foods to your diet or supplement. If you do choose to supplement (which I’m currently doing), this is the one I use.
Best Sources of Magnesium
Thankfully there’s magnesium in a ton of foods. Magnesium-rich foods include nuts and seeds, beans, vegetables and even chocolate!
The list is pretty lengthy, so I’m just going to stick with my top 12 plant-based sources of magnesium. If you want to see the full list, check out this article from the Cleveland Clinic.
Food Sources of Magnesium (with daily percentages):
How to Get More Magnesium in Your Diet
Worried you’re not getting in enough magnesium? The first thing I’d do is work with your healthcare provider to see if it’s a nutrient you need to be concerned about. If you’re well within the normal levels, then you don’t need to change a thing. If you’re a bit on the lower end, here are some recipes that are packed with magnesium:
- Chocolate Peanut Butter Quinoa Parfaits
- Chocolate Steel Cut Oats
- Super Seed Homemade Peanut Butter
- Instant Pot Spicy Black Beans
- Creamy Superfood Kale & Lentil Quinoa Salad
- Tahini Quinoa Brownies
- Healthy Chocolate Quinoa Breakfast Bowls
And the list goes on and on! As you’re searching through the site for recipes, look for ones that contain chocolate, quinoa, legumes, leafy greens, avocado, nuts and seeds, and oats! ????
Got Magnesium-Related Questions?
If so, drop them in the comments! I’m planning to talk more about other vitamins and minerals in the next few weeks, so definitely let me know what you want me to talk about next.
The Benefits of Chlorophyll
1. Skin healing
Chlorophyllin has been shown to reduce inflammation and bacterial growth in skin wounds.
A 2008 review of wound care studies found that commercial ointments with papain-urea-chlorophyllin are more effective than other treatments. The ointment also reduced pain and healing time by half. Your doctor can prescribe this ointment.
Chlorophyllin may also be effective for mild to moderate acne. In a 2015 study, people with acne and large pores saw skin improvement when they used topical chlorophyllin gel for 3 weeks.
2. Blood builder
Some people suggest that liquid chlorophyll can build your blood by improving the quality of red blood cells.
A 2005 pilot study found that wheatgrass, which contains about 70 percent chlorophyll, reduced the number of blood transfusions needed in people with thalassemia, a blood disorder.
But the study authors didn’t conclude that chlorophyll was the reason for the decreased need for transfusions.
Dr. Chris Reynolds, a clinical expert in wheatgrass, believes that the benefits come from wheatgrass itself rather than from the chlorophyll.
It’s unclear how wheatgrass affects red blood cells. But it’s believed that chlorophyll is destroyed during the production of wheatgrass extract.
3. Detoxification and cancer
Researchers have looked into the effect of chlorophyll and chlorophyllin on cancer. One animal study found that chlorophyll reduced the incidence of liver tumors by 29 to 63 percent and stomach tumors by 24 to 45 percent.
There have only recently been human trials. A small study of four volunteers found that chlorophyll may limit ingested aflatoxin, a compound known to cause cancer.
According to International Business Times, there’s a clinical trial in China on the effects of chlorophyllin on liver cancer. This trial is based on the findings from an old study where chlorophyllin consumption led to a 55 percent decrease in aflatoxin biomarkers.
4. Weight loss
One of the most popular claims associated with liquid chlorophyll is weight loss support.
A study found that people who took a green plant membrane supplement including chlorophyll on a daily basis had greater weight loss than a group that didn’t take the supplement.
The researchers also found that the supplement reduced harmful cholesterol levels.
5. A natural deodorant
While chlorophyllin has been used since the 1940s to neutralize certain odors, studies are outdated and show mixed results
The most recent study of people with trimethylaminuria, a condition that causes fishy odors, found that chlorophyllin significantly decreased the amount of trimethylamines.
As for claims about chlorophyllin reducing bad breath, there’s little evidence to support it.
Magnesium in Plants and Soil
Magnesium is an essential plant nutrient. It has a wide range of key roles in many plant functions. One of the magnesium’s well-known roles is in the photosynthesis process, as it is a building block of the Chlorophyll, which makes leaves appear green.
Magnesium deficiency might be a significant limiting factor in crop production.
Magnesium Pools in Soils
In soil, magnesium is present in three fractions:
- Magnesium in soil solution – Magnesium in soil solution is in equilibrium with the exchangeable magnesium and is readily available for plants.
- Exchangeable magnesium – This is the most important fraction for determining the magnesium that is available to plants. This fraction consists of the magnesium held by clay particles and organic matter. It is in equilibrium with magnesium in soil solution.
- Non-exchangeable magnesium – Consists of the magnesium that is a constituent of primary minerals in the soil. The break down process of minerals in soils is very slow; therefore, this magnesium fraction is not available to plants.
Magnesium Uptake by Plants
Plants take up magnesium in its ionic form Mg+2, which is the form of dissolved magnesium in the soil solution. The uptake of magnesium by plants is dominated by two main processes:
- Passive uptake, driven by transpiration stream.
- Diffusion – magnesium ions move from zones of high concentration to zones of lower concentration.
Therefore, the magnesium amounts that the plant can take up depend on its concentration in the soil solution and on the capacity of the soil to replenish the soil solution with magnesium.
Magnesium Availability and Uptake
Conditions such as, low soil pH, low temperatures, dry soil conditions and high levels of competing elements, such as potassium and calcium, reduce the availability of magnesium. Under such conditions, magnesium deficiency is more likely.
Effect of Soil pH on magnesium availability:
- In low-pH soils, the solubility of magnesium decreases and it becomes less available.
- Due to the large hydrated radius of the magnesium ion, the strength of its bond to the exchange sites in soil is relatively low. Acidic soils increase the tendency of magnesium to leach, because they have less exchangeable sites (lower CEC).
- In addition, in acidic soils, elements such as manganese and aluminum become more soluble and result in reduced magnesium uptake.
- Other positive-charged ions, such as potassium and ammonium may also compete with magnesium and reduce its uptake and translocation from the roots to upper plant parts. Therefore, excessive applications of these nutrients might prompt magnesium deficiency. Care should be especially taken in sandy soils, as their CEC is low and they can hold less magnesium.
Magnesium deficiency, like any deficiency, leads to reduction in yield. It also leads to higher susceptibility to plant disease.
Since magnesium is mobile within the plant, deficiency symptoms appear on lower and older leaves first. The first symptom is pale leaves, which then develop an interveinal chlorosis. In some plants, reddish or purple spots will appear on the leaves.
The expression of symptoms is greatly dependent on the intensity to which leaves are exposed to light. Deficient plants that are exposed to high light intensities will show more symptoms.
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Magnesium Deficiency In Plants
The Role of Magnesium in Plants.
Magnesium is an essential plant nutrient and is a key element of the chlorophyll molecule. Chlorophyll makes plants green and is used by a plant to convert sunlight into energy via photosynthesis.
No magnesium, no photosynthesis.
Photosynthesis is the complex process whereby a plant uses the chlorophyll molecule(s) to convert carbon dioxide, water, and certain inorganic salts into carbohydrates. Carbohydrates form the building blocks for all plant cells.
Symptoms of a Magnesium Deficiency
One of the first signs of magnesium deficiency is chlorosis. Chlorosis is the yellowing of the leaf structure found between veins, giving the leaf a marbled appearance, while the veins remain green. Another indication of chlorosis is for the leaf margins to turn a red-brown-purple colour.
Magnesium is mobile in plants and when a deficiency occurs, chlorophyll in the older leaves is broken down and transported to the new plant growth. This is why chlorosis symptoms manifest in the older leaves first.
If the deficiency is not corrected, the chlorosis will eventually manifest in the new growth. The continued deficiency of magnesium results in leaf necrosis and the dropping of the older leaves will occur. Magnesium is also an activator for various enzymes and a deficiency will lead to a decrease in enzyme activity which will also affect plant growth. Magnesium stabilises the ribosome structures and the breakdown of these structures leads to premature ageing of the plant.
Magnesium plays an important role in many other plant functions such as:
Nutrient uptake control.
Aid nitrogen fixation in legume nodules.
Plant oil and fat formation.
Increases iron utilisation.
We can see that magnesium plays a very important role in maintaining plant growth and health.
Correcting Magnesium Deficiency
Fortunately, it is not difficult to correct magnesium deficiency and below are a few suggestions for you to consider:
Use a fertiliser that includes magnesium in its formulation such as the Dyna-Gro Nutrient Solution range. Doing this means that every time you feed your plants you are providing them with magnesium. Alternatively, you can include into your plant nutrient application programme, a fertiliser that has a magnesium base such as Dyna-Gro Mag-Pro 2-15-4. Mag-Pro has 2% magnesium in its formulation as well as 1.5% sulphur.
Consider starting a regular foliar application of a solution containing magnesium.
Apply dolomitic lime to your soil and or include dolomitic lime in your growing medium.
The application of Epsom Salts is also an effective way to apply magnesium. Use it as a soil drench diluted 25 grammes per litre of water.
I use the following programme for my plants.
Every time I water my plants I ensure that I use one of the Dyna-Gro Nutrient Solutions. Mostly I use Liquid Grow or Foliage-Pro as my base fertiliser. If my plants are approaching flowering or in flower I switch to Liquid Bloom.
Once a month I switch one of the above for Mag-Pro.
I always include Pro-TeKt with all my mixes.
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