The Content Of The Article:
- Composition of Epsom salt
- Detect magnesium deficiency
- Reasons for magnesium deficiency
- Remedy acute magnesium deficiency
- Properly fertilize with Epsom salt
- Epsom salt as sulfur fertilizer
Composition of Epsom salt
The chemical name of Epsom salt is magnesium sulfate - as a fertilizer, the Epsom salt therefore provides only the two plant nutrients magnesium and sulfur. It contains about 15 percent magnesium oxide (MgO) and twice as much sulfuric anhydride (SO3). The most important ingredient is magnesium: it is a central component of the plant pigment chlorophyll, or leafy green, which is needed by plants for building up sugars. In turn, the plant produces cellulose and various other endogenous substances.
The Epsom salt is not only offered as a magnesium fertilizer, but is also part of various complex fertilizers, so-called "complete fertilizer".
Detect magnesium deficiency
Magnesium deficiency occurs mainly in spruces, firs, pines and other conifers, which grow on magnesium-poor, mostly acidic sandy soils. The needles turn from the tip beginning to the beginning first creamy white to yellow, later brown. In deciduous trees, leaf yellowing usually begins along the midrib, leaving the leaf veins and a subsequent narrow strip of leaf surface green. In some vegetables, such as cabbage, the leaves sometimes show reddish marbling. By the way: An iron deficiency is shown by almost identical symptoms, but these occur only on the young leaves.
Why magnesium deficiency occurs more frequently, especially in conifers, is still not fully understood. One reason could be that the evergreen conifers do not master nutrient recycling as well as the deciduous deciduous shrubs. The latter store most of the valuable minerals from the leaves before shedding them. The conifers, however, renew their needles continuously, but each needle remains on the plant for several years before it is repelled and replaced with a new one. However, before being dropped, the contained leaf green is not so thoroughly decomposed and recycled.
You can recognize magnesium deficiency in deciduous trees such as this hydrangea on the clearly discolored leaves
Reasons for magnesium deficiency
As with calcium, which is quite similar in its chemical behavior to magnesium, the nutrient is easily washed out by precipitation, especially on sandy soils - the losses are up to three grams per year and square meters. In loamy soils, magnesium is less volatile, as it can attach to the clay minerals. An oversupply of potassium and calcium can cause a magnesium deficiency, as the two plant nutrients also attach to clay minerals and are usually present in the soil in much higher concentrations.
Remedy acute magnesium deficiency
Epsom salt is very soluble in water. Therefore, you can spray the fertilizer in liquid form with a spray directly to the leaves or needles. The nutrient is absorbed directly by the leaves and has a particularly fast effect - a major advantage for acute deficiency symptoms. As a foliar application one uses a one-percent Epsom salt solution, which corresponds to 10 grams of Epsom salt per liter of water.
Properly fertilize with Epsom salt
For a so-called maintenance fertilization, you should distribute about 50 grams of Epsom salts per square meter in the outer area of the treetop on acidic sandy soils in the spring. If a conifer already suffers from magnesium deficiency, fertilize the root area with around 100 grams of Epsom salts per square meter, in addition to the foliar application mentioned above.
Epsom salt as sulfur fertilizer
Due to its high sulfur content, the bitter salt is also excellent for sulfur fertilization. Before the introduction of car catalysts and flue gas desulphurisation in coal-fired power plants, sulfur deficiency almost never happened. The so-called "acid rain" - with the sulfur dioxide from the air enriched precipitation - made enough supplies. Fortunately, this sulfur source has dried up, because the consequential damage was immense: The creeping acidification of the soil led among other things to forest dying, which was a big topic in the 80s.
Sulfur deficiency in plants is still rare today, but is more common. The deficiency phenomenon is similar to the lack of nitrogen, because the entire leaf including the leaf veins turns yellow. The deficiency symptoms are limited in contrast to the lack of nitrogen but mostly on the young leaves.
Anyone who regularly supplies their soil with compost or rotten cattle dung does not have to worry about sulfur deficiency. The fertilizer manufacturers also reacted years ago to the positive changes in environmental conditions, as mineral and organic complex fertilizers now contain enough sulfur to prevent deficiency symptoms.