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Manganese

Trace element
Manganese is an essential trace element. It is a catalyst that functions in cell membranes and the production of chloroplasts. Soils with a lack of manganese produce plants with a yellow-greenish colour between the nerves of the leaves (this can also occur as a result of lack of other elements like iron or magnesium or other causes). This phenomenon is also called "chlorosis", or "decolourization of leaves". The production of chlorophyll is slowed down if there is a lack of manganese. A shortage of manganese is widespread, special on soils with a pH above 6.2. The pH is more important for the uptake of manganese in plants than the amount of manganese in the soil. The critical manganese deficiency level for most plants ranges from 15 to 25 mg/kg in the dried leaves. The toxic concentration of manganese to plants is more variable, depending on both plant and soil factors. Generally, most plants are affected by a manganese content around 500 mg / kg analyzed in dry leaves. An adequate soluble silicate supply to plants is reflected in the easy transport of Mn and a more homogeneous Manganese distribution in the plant. Other elements like magnesium, potassium, sodium and ammonium affect the uptake of manganese and vice versa.

Manganese analysis

In our analysis we analyze two fractions of manganese in the soil. The first is the reduced, soluble fraction of manganese, extracted with a very light concentration of neutral calcium chloride. The second one is the total amount of extractable manganese. Most of this manganese is in the oxidized or attached to soil particles.

Manganese and livestock.

Grass with a lack of manganese can cause manganese deficiency in the animal. This can cause bone problems and cattle can become more nervous. Fertilization is in this case not useful, extra manganese has to be fed by other feed next to the hay or grass, or grass silage.

Manganese and oxygen

If the soil structure is bad and/or if the oxygen demand in de soil is high, the amount of reduced, soluble manganese in the soil will be elevated. To normalize this situation, aeration (oxidation) of the soil may give the desired result. A healthy soil life requires a sufficient amount of air. When also the biological oxygen demand and the oxygen status are already affected, the duration of healing can take several years. Especially when also oxygen shortage in the sub soil is detected. On basis of these results, we recommend a special soil treatment, depending on the situation at hand.

Manganese and natural soil chelates.

The in water-soluble humic acids and some other water-soluble organic compounds in the soil water can bind manganese temporally. It works like a synthetically formed chelate. When many trace elements like manganese in the form of metal ions are bound by these natural chelates, the amount of free ions that can be taken up by a plant is also higher. Therefore a high amount of natural chelates in the soil is benedictional to the uptake of trace elements as manganese.

More on manganese (Mn)

Manganese is one of the most abundant trace elements in the lithosphere, and its common range in rocks is 350 to 2000 mg/kg. The utmost part of this manganese is not in a form that a plant can take up. During weathering secondary manganese containing minerals will be formed. Manganese can show in ion form in 3 forms: 2+, 3+ and 4+. These Because of this variety of ions form, that change constantly, manganese is a more complex element. This capacity of change in valence makes manganese a catalyst in processes in the soil and within the plant. Some manganese 4+ containing minerals like MnO2 are black. Sometimes they can be found in lithe or bigger concretions that can be seen in a soil, but also on the bottom of the Atlantic Ocean. Manganese 4+ is the oxidized form; Mn 2+ is the reduced form. The Mn 3+ form is in between. Oxidizing elements in the soil will transform Mn 2+ to Mn 3+ of even Mn 4+. Reducing elements like Iron(II) and Chromium(III), reduced S, phenols and other easily oxidized organic compound transform Mn 4+ via Mn3+ to Mn 2+.