Roots take their nutrients from the soil. The soil is negatively charged and binds nutrient cations to hold them for roots to actively uptake the preferred ion depending on its growth stage. If these nutrients are not bound to the soil they get flushed away by water.
Interactions of charges are described by coulombs law and basically says that a stronger ionic bond is formed by aa larger charge or a smaller distance between the opposite charges. Thats why pH is so important. The hydrogen cation is very small and easily binds with the soil. So other bigger cations get flushed away.
Another factor is concentration. A large concentration of a certain cation balances the binding equilibrium of all cations towards the cations that are present in a larger concentartion.
But Potassium has negative influence on the uptake of manganese. Why?
Potassium has an ionic radius is a lot bigger than that of manganese. Manganese also has two carges (+2).
But then again. Potassium is present in a far larger concentration in general. In my case PK:Mn = 1 : 0,06.
Is this caused by the balance caused by this concentration balance. And why are other small cations not effected?
Why does a high concentration of potassium prevent the uptake of manganese by roots?
2021-01-31 7:44 pm
回答 (1)
2021-01-31 10:47 pm
Potassium has negative influence on the uptake of manganese. Why?
Where too much potassium is applied, if either by itself, the total saturation exceeds 10% of the soils nutrient holding capacity (TEC), it will begin to cause plant uptake of manganese to be blocked. In such cases, soil tests show the soil has plenty of manganese, but there is so much potassium there that the manganese has trouble competing in terms of availability and uptake by the root. This was the problem that some crops were having in the field. The higher the percentage goes above 10% K, the harder it will be to get manganese taken up by the plants even though the soil test may show excellent manganese levels. Even though the excessive level of potassium does not tie up the availability of manganese in the soil, it does, along, block adequate manganese uptake via the soil into the plant.
Where too much potassium is applied, if either by itself, the total saturation exceeds 10% of the soils nutrient holding capacity (TEC), it will begin to cause plant uptake of manganese to be blocked. In such cases, soil tests show the soil has plenty of manganese, but there is so much potassium there that the manganese has trouble competing in terms of availability and uptake by the root. This was the problem that some crops were having in the field. The higher the percentage goes above 10% K, the harder it will be to get manganese taken up by the plants even though the soil test may show excellent manganese levels. Even though the excessive level of potassium does not tie up the availability of manganese in the soil, it does, along, block adequate manganese uptake via the soil into the plant.
收錄日期: 2021-04-24 08:28:24
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