Minerals Flashcards
Mineral Groupings (2)
Macronutrients: 3 Primary, 3 Seconary
Micronutrients: 7 Trace Elements
Primary Elements (NPK)
N: Nitrogen
P: Phosphorus
K: Potassium
On Fertilizers they are always listed in this order N-P-K
Seconary Elements:
Calcium (Ca)
Magnesium (Mg)
Sulfur: (S)
Micronutrients:
Iron (Fe) Boron (B) Manganese (Mn) Copper (Cu) Zinc (Zn) Molybdenum (Mo) Chlorine (Cl)
Nitrogen
Vital Component! New Plant Growth Needs Nitrogen (Vegetative Stage)(Tissue Growth)
Active within the plant
Not reliable in a soil test because it is prone to leaching
Volatilization:
If there is insufficient oxygen content in the soil, the bacteria will steal it from the nitrates. The resulting N2 is then released into the atmosphere as a gas. This is called volatilization.
Luxary Consumption:
With each nutrient, there are problems associated both with toxicity (too much) and deficiency (too little). Nitrogen toxicity depends on which form has been taken up in excess. When nitrates are taken up, it is called luxury consumption.
Ammonium Toxicity
Ammonium toxicity is slightly different. Having too much ammonium in the soil could lead to nitrogen deficiency signs if the nitrifying bacteria are not active. Also, there could be negative effects if the plant is sensitive to pH changes in the soil. the plant more than being a problem because there is too much of a certain kind of nitrogen. Observable symptoms would be interveinal chlorosis progressing towards necrotic spots on the younger leaves. The edges of leaves may curl up or downward and there will be stunted or dying roots.
Phosphorus:
Phosphorus, although being the second mineral stated in the fertilizer analysis, is used in lesser amounts in the plant proportionate to potassium and nitrogen. It is, however; still vital to plant processes. In the process of photosynthesis, phosphates are the short term energy holders used to bundle up light energy and transfer it into carbon bonds. When a DNA strand is inspected closely, the two sides of it are made up of a phosphate and a sugar molecule. Without phosphorus, the plant will literally not have means to transfer energy or the building blocks for DNA. Phosphorus is also used in the process of cell division (mitosis) and differentiation of cells into tissues of the reproductive parts of plants (meiosis). It is also required for the formation of seeds. Found in meristematic parts of the plant, Phosphorus is associated most often with root development
Phosphorus Excess/Deficiencies:
There are no special leaf symptoms associated with excessive levels of phosphorus. When there are very high levels of phosphorus in a medium, an iron deficiency is often induced. Similarly, a high iron level may cause a phosphorus deficiency. Deficiencies in phosphorus usually present first as poor establishment in newly propagated plant material. A secondary indicator may be the plant turning a deep green colour and then a purplish red hue to the plant.
Potassium (K):
Unlike nitrogen or phosphorus, potassium is available for uptake in its ionic form. While nitrogen and phosphorus are converted into compounds essential to plant growth, potassium is found in the plant as a soluble salt. It is thought that potassium aids in metabolism where nitrogen is converted into protein.
It is highly mobile within the plant and is susceptible to luxury consumption. This excessive uptake does not really pose a problem in the way that it would with nitrogen, except that when managers remove clippings, they may inadvertently deplete the plant of potassium that would normally return to the soil profile when the clippings biodegrade. It is possible as well, that excess of Potassium within the plant will hinder magnesium uptake; therefore, a sign of luxury consumption of Potassium may be observed as a deficiency in magnesium.
Calcium (Ca):
Calcium is absorbed in the ionic form (Ca++). Most of the calcium in a plant is found in the middle lamellae of the cell walls of the leaves. Much of the stiffness of a plant is due to calcium. It also prevents the leaching of the mineral salts from the cells and appears to influence the growth of the apical meristems of the plant.
Magnesium (Mg):
This element is absorbed as (Mg++). Magnesium is the central mineral element contained in chlorophyll. It is interesting to note that the main difference between human hemoglobin and plant chlorophyll is that humans have iron as the central mineral and plants have magnesium. As you can imagine, deficiency symptoms will be aligned with a lack of chlorophyll: the yellowing of leaves. A number of plant enzymes also require magnesium to work properly.
Sulfur (S):
Roots absorb sulphur in the form of sulphate (SO4–). Small amounts of sulphur may also be absorbed through the leaves as sulphur dioxide (SO2), but excessive sulphur dioxide in the air will result in leaf injury. When it is in high humidity scenarios, it combines with water to become sulphuric acid. Sulphur is involved in the formation of chlorophyll, but is not a component of the molecule itself.
Trace Elements:
Trace elements are all immobile in the plant, once they arrive, they are set in place. They move through the Xylem stream, so they only move one direction: from the roots to the shoots. As a result, if there is insufficient supply, it will show up in the new leaves first. Because these elements are needed in such small quantities, imbalances are usually the result of over-refining (water that is too pure, soils too clean) or pH problems. These other factors should always be checked before trying to add more of one particular trace element.
If it is decided that Trace Elements do need to be added, there are a couple of options as far as formulation. Chelated is the most immediately available
