Iron as a nutrient is mainly used for the formation of enzymes. Learn how iron fertilizer is used and whether it is toxic. Not only we humans can suffer from iron deficiency, but also plants can lack this trace element. In this case, fertilization with iron is necessary.
We have iron deficiency due to headaches, fatigue, brittle nails, and many other symptoms. But how do we see in our plants whether they lack iron and we need to help with some fertilizer? We will provide you with the answer to this question as well as further information on the subject of iron fertilization.
Before we go into more detail about the application of iron fertilizer and its mode of action, it is important to understand what properties iron possesses and why our plants need iron.
Characteristics of iron at a glance
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Iron is an important part of our lives. As a building material it is used in our houses and even our breakfast juice is enriched with iron. We can also discover iron in the periodic table, under the symbol Fe, derived from the Latin name Ferrum. Iron is a heavy metal that is used either as two- or three-valent iron (Fe2+ or Fe3+) or in compounds (oxides, salts). For our plants, only the Fe2+ interesting, because they can absorb them and feed on them.
The Fe3+ is not directly available for the plants. The bound iron can be released from different minerals by weathering. In this weathering, iron ions are released, but several factors influence the availability of iron, such as pH and humidity. In moist soil with a pH of 6 to 6.5, there is usually a high amount of2+. If the pH value rises to over 6.5 and you also have to contend with drought, this availability decreases more and more. The iron is bound and is no longer available to the plant.
Why do plants need iron?
Iron is not a direct component of the leafy green (chlorophyll) responsible for photosynthesis, but it plays an important role in its formation. It acts as a catalyst – that is, it accelerates and supports the formation of leafy greens.
Iron has another important task in the breathing of plants, more precisely in connection with the respiratory chain. The respiratory chain is part of energy metabolism. Energy is generated from the nutrients absorbed – a very important process for all living beings. Iron is often also part of different enzymes that play different roles in metabolism.
The Fe3+ is not directly available for the plants, as it must first be used in the soil in Fe2+ converted or chelated. Plants can only be2+ or chelated Fe3+ Record. Chelates are complexes that can be absorbed by the plants as whole molecules. The word “chelate” comes from the Greek chele and means as much as claw or crab scissors – and that also describes well what chelates are in the first place.
In the middle of a chelate is an ion, often a heavy metal like iron. Larger organic molecules cling to it and hold it. These compounds are very stable, nutrients can be absorbed more easily by the plant as a chelate.
Detecting iron deficiency in plants
How does an iron deficiency in our plants show up? A symptom of iron deficiency is the yellowing of leaves, whereby the leaf veins remain green – these are so-called chloroses. These chloroses first form on the young leaves. When the deficiency becomes more pronounced, necrosis (dying tissue) develops from the edge of the leaf.
When an iron deficiency occurs, a lack of chlorophyll, protein, and energy also occurs. Therefore, the growth as well as the yield of the plant decreases. The color of flowers can also fade and they can remain smaller overall. The roots are usually short in case of iron deficiency and have many short side roots. If the iron deficiency is not treated, your plants can even die – but only if it is a severe deficiency.
Iron deficiency is often found, especially on calcareous soils, where iron is precipitated by the calcium carbonate present there. As a result, the iron can no longer be absorbed. Some plants can already show on which soil they grow – for example, soils on which a lot of flattish, nettles, or dandelions grow are often chalky. Further information on chloroses is also collected here in a special article for you.
Summary Signs of iron deficiency in plants:
- Presence of chlorosis, with the leaf veins remaining green
- Signs first appear on the young leaves
- Later, necrosis from the edge of the leaf begins
- Inhibited growth
- Low yield
- Pale, small flowers
- The occurrence of short roots and many side roots
Dryness and compaction may also be reasons why the plant cannot absorb iron. Therefore, after a prolonged drought, it is worth watering the plants properly. Wet and compacted soils can also be a hindrance to the iron absorption of the plants. Such soils often inhibit root growth and there is a lack of oxygen or at the same time an excess of carbon dioxide. Mechanical loosening and the incorporation of mainly organic fertilizers can put an end to compaction.
Another important factor that causes iron deficiency is the excess of other heavy metals in the soil. The transport and absorption of iron can be inhibited when many ions of chromium, copper, cobalt, zinc, manganese, or nickel romp in the soil. Rindenhumus can contain a lot of manganese and especially a zinc excess can lead to an iron deficiency.
In general, it can be said that problems have to be expected as soon as the balance of the ions in the soil is disturbed. The interaction between iron and phosphorus is particularly interesting. If there is a lot of phosphorus in the soil, it is possible that these two nutrients combine and form iron(III) phosphate. We know this compound as a snail grain, but it can also form in the soil and thus bind the nutrients.
Here we have briefly listed the iron deficiency triggers:
- Too high pH
- Inhibited root growth
- Imbalance and excess of other nutrients
- High phosphorus content
Apply ingenuity iron fertilizer
If your plants are now affected by an iron deficiency, there are several ways to feed them. Since iron can be absorbed through the roots and over the leaves, several applications are available to you.
Iron leaf fertilization
Iron can be fertilized not only over the soil but also as leaf fertilization. The advantage of leaf fertilization is that the effect occurs very quickly. Since the fertilizer is not introduced into the soil, it cannot be washed out and is effective despite soil dryness. However, leaf fertilization can only be used with a low concentration to avoid damage to the leaves.
This form of fertilization must also be used more frequently and the fertilizers are unfortunately also slightly more expensive than other iron fertilizers. It is also possible to use iron fertilizer regularly as a preventive measure and thus counteract deficiency symptoms. However, always follow the product description and the recommended doses. When using iron fertilizers, it is also important not to use them in the sun and at temperatures above 77 °F – this can lead to plant damage.
Iron fertilizer in the water
You can also add iron to the water. For this purpose, dissolve the iron fertilizer according to the product description in the watering water and add it to the plants. In the water, a quantity of 0.1 to 0.2 oz of iron per liter of water is sufficient for proper iron fertilization.
Then rinse the watering can thoroughly to remove the last product residues from it. Also, be careful not to soil the soil or your clothing with iron fertilizer. This results in unsightly rust stains, which are either difficult to remove or impossible to remove.
Which plants are often affected by iron deficiency?
Put simply, particularly depleting cultures are often affected. Ornamental plants such as roses (pink), hydrangeas (Hydrangea), magnolias (magnolia), and rhododendrons suffer particularly frequently. Rhododendron and rose fertilizers often contain a small amount of iron to prevent chlorosis due to iron deficiency. Also, strong-eaters among the vegetables such as tomatoes (Solanum lycopersicum), cucumbers (Cucumis sativus), and peppers (Capsicum) have to contend with the lack of iron.
In the case of fruit, one often finds one with berries, apples (malus), and quinces (Cydonia oblonga). The flower lovers among you, who like to have petunias (Petunia) on the balcony, will surely have been confronted with an iron deficiency. When chlorosis occurs in the petunias, it is usually an iron deficiency.
Iron fertilizer for lawns and against moss
Even your favorite green lawn can suffer from iron deficiency. This is mostly caused by the soil condition. Some soil contains more iron, others contain less iron. However, in order to be quite sure, you can carry out a soil survey.
One way to use iron fertilizer on the lawn is to combat unwelcome moss. If your lawn is heavily mossed, you can treat the moist moss with iron fertilizer. Before doing so, you should mow the lawn to a length of about 1 to 1.5 in. and then treat the moss with the iron fertilizer (iron (II)sulfate). Iron fertilizer can be used either as granules or, as already described, as liquid fertilizer mixed into the water.
The application should take place in the spring in the months of March or April if the soil is already completely thawed. After that, the moss dies after about two weeks and turns brownish to black. You can then simply remove the moss with a rake or rake. It is especially important that you fill the gaps left by the moss.
After removal, you should sow grass again so that no other weeds or moss settle. If you do this moss removal in spring, this is ideal so that the reseeding can grow well. Do not enter the lawn after using iron fertilizers for about two weeks. Also, keep your pets away from the lawns – there may be signs of poisoning.
We always recommend supplying your lawn with sufficient nutrients and relying on organic long-term fertilizers. This not only makes your lawn fit and lush green but also spares you the soil life, and can always re-enter your lawn immediately after fertilization.
Iron fertilizer for aquariums
Aquarium plants also need nutrients, because when the plants show chloroses, they also lack iron. The fact that an iron deficiency in the aquarium is not so rare is shown by the fact that the first aquarium fertilizer in the trade was an iron fertilizer. A general quantity recommendation cannot be given for the application. Each aquarium is individual in terms of filling volume, filter systems, stocking, feeding, and planting.
Optimal iron content in an aquarium is 0.03 to 0.1 mg/l. This can be easily checked with test strips from the zoo department. Another indicator of sufficient iron content is the growth of water lenses. If you have water lenses in the aquarium and enough iron, then the lenses multiply well.
If there is a lack of iron, the water lenses adjust their growth. Unfortunately, fertilization in the aquarium – no matter what nutrient is involved – is often associated with the formation of algae. Therefore, you should be very careful when dosing and rather fertilize a little less than too much.
Is iron fertilizer toxic?
In general, iron fertilizers are toxic and you should always avoid physical contact with these fertilizers. Wash your hands thoroughly when you come into contact with them. If you have any complaints after contact with iron fertilizer, be sure to consult a doctor.
But it is not only the toxicity that needs to be taken into account but also the unsightly stains that the iron fertilizer could leave on your soil or other objects. The rust stains are usually difficult to remove or not at all. Be careful with your clothes. It would be a great pity for your favorite trousers if it was soiled with unsightly stains.
Manufacture iron fertilizers yourself
If you don’t want to buy iron fertilizer, there is another option: that of your own production. This will protect your wallet and, of course, the environment. Because plants absorb iron as an essential nutrient, it is naturally contained in vegetable waste, bokashi, or compost. Highly ferrous plant material such as spinach, chickpeas, lentils, or kidney beans is particularly suitable for the production of ferrous fertilizer.
Because the two-valued, more plant-available iron is only available in the compost at a low pH, it can be mixed with lemon juice or orange juice before use as a fertilizer.
Similarly, an old trick works to feed iron to our bodies. Iron nails inserted into an apple oxidize as a result of contact with apple acid. Mixing the apple carvings then crushed under the plant-soil also provides easily plant-available iron. But it’s even easier: Many plants themselves have such effective tactics for extracting iron from the soil that inserting iron nails into the plant-soil can be enough.
When planting, especially in the container – to impart plenty of yellow sand can also prevent iron deficiency. Because the yellowing of the sand comes from adhering iron oxides. Another very effective iron supplier is a blood meal, which can be purchased or obtained from your own slaughter.