Minerals: their properties and importance in plant nutrition
Science has learned that some chemical elements are essential for plant life. Minerals in plants are the building material for the formation of roots and woody tissues. The three main nutrients are nitrogen (N), phosphorus (P) and potassium (K). Together they form a trio known as NPK and play a complex role in plant growth. Other important nutrients are calcium, magnesium and sulfur. Plants also need small amounts of iron, manganese, zinc, copper, boron, and molybdenum, known as trace minerals, because plants only need trace amounts.
Important! Deficiency of any of the important nutrients slows down growth, the plant is depleted and dies.
The most important nutrient for plants is nitrogen, a key element in plant growth. At the beginning of the growing season, plants consume a lot of nitrogen to form new shoots, leaves and roots. It is quickly depleted and needs to be replenished frequently with nitrogen fertilizers. If this is not done, there will likely be slow and retarded growth, light green leaves and premature dropping. It is taken up by plants as it decomposes organic materials, and when applied to the soil, it is converted to its mineral form (nitrate). Never fertilize with nitrogen at the end of summer (the last dose of nitrogen fertilizer should be applied in July) otherwise wintering can be complicated, as the wood will not be mature enough.
Note! The lack of nitrogen in the soil is manifested by stunting of plants, light green color of the leaves and their premature fall. Excessive use of nitrogen fertilizers causes excessive growth of green mass, especially leaves. They become less disease resistant. Therefore, when adding nitrogen to the soil, special care must be taken.
Nitrogen intake also depends on the age of the plant; the younger the trees and bushes, the more nitrogen they need.
The soil itself can also obtain nitrogen with the help of plants. Legumes, such as peas or lupins, take nitrogen from the air, store it in the soil, and make it useful for plants. This is possible, for example, by planting green manure.
Phosphorus for cultivated plants
The amount of nitrogen and phosphorus must be balanced. Phosphorus is essential for the viability of all plants: it helps transfer energy from sunlight to plants, stimulates root growth, shortens the growing season and speeds up fruit ripening.
Fruit trees and shrubs need this element the most during development. The lack of phosphorus is manifested in the wilting of leaves and the formation of fruits without smell and taste, affects the development of seeds.
Phosphorus related growth factors:
- stimulates root development;
- increases the strength of the stems;
- improves flowering;
- more uniform and earlier ripening of the crop;
- increases the ability of nitrogen to be fixed from legumes;
- improves the quality of the crop;
- increases the resistance of plants to diseases.
Phosphorus deficiency is more difficult to diagnose than nitrogen or potassium deficiency. Crops usually show no obvious symptoms other than a general stunting early in development.
Potassium is associated with the movement of water, nutrients and carbohydrates in plant tissues, helping plants survive the winter. Most of all, young plants need it, which it helps to gain resistance to low temperatures, affects the size, shape and viability of seeds. With a potassium deficiency, they are less resistant to drought, excess water, high and low temperatures, pests and diseases.
Calcium plays an important role in the regulation and growth of plants. It is used as a building material, especially for woody tissue and roots. Nutrients are constantly accumulated in plants. Acidic sandy soils are predominantly calcium-poor areas of land.
If the plant is deficient in calcium, root growth slows down: there are few lateral roots, and capillary roots are often almost completely absent. On the other hand, excess calcium does not allow plants to absorb valuable nutrients, especially iron, magnesium, phosphorus and other elements. Peat should be added to the soil.
The importance of iron for plants is determined by its role in many enzymatic reactions. Iron deficiency is uncommon in soils, plants can usually get enough of this mineral from natural sources. But the uptake of iron by plants can be reduced if the soil pH is not between 5 and 6.5.
In acidic soils, iron is very available to plants and can be toxic to them. Excess iron reduces the intake of calcium, manganese, boron, as well as phosphorus and potassium. Iron deficiency sometimes manifests itself as an excess of calcium in the soil. With an increase in alkalinity, its availability to plants decreases. Its deficiency disrupts the mechanism of chlorophyll formation, so spots appear on young leaves between the leaf veins – chlorosis.
Important! Excess calcium in the soil can block iron for plant needs. In calcareous soils add iron with more care.
Chlorine is important for photosynthesis and gas exchange between the plant and the environment. The symptoms are difficult to recognize and are often mistaken for various diseases. The most sensitive to chlorine are grapes, berries, and potatoes.
Magnesium is one of the most important nutrients for plants, especially during periods of their growth: it is of great importance in the formation of flowers, fruits, seeds.
It is especially necessary for plants to form chlorophyll, as it is an important component of greenery. Magnesium deficiency is the cause of leaf chlorosis. Compared to other elements, plants do not need too much magnesium, in most cases the natural soil supply is sufficient. Magnesium deficiency is usually caused by excess calcium in the soil.
Sulfur deficiency in natural conditions usually does not occur. Most plants require very little, especially fruit trees and shrubs. On the contrary, onions, celery, leeks and garlic are highly sought after.
In addition to macronutrients, plants need elements that they receive in small quantities. For this reason, they are called trace elements.
Boron is of great importance, especially for legumes and potatoes, but also for the proper development of other plants. Boron deficiency is manifested by drying, twisting of the leaves. Boron deficiency also contributes to the development of certain diseases such as apple scab.
Silicon is important as a building material. Along with calcium, it plays an important role in the formation of wood.
Manganese is associated with the quality of the grown plant products.
Cobalt. It is needed mainly by legumes, which bind atmospheric nitrogen to the soil.
Copper plays a role in plant metabolism. In its absence, the viability of pollen is reduced. It is toxic at higher concentrations.
Zinc is needed for regulatory processes. With its deficiency, yellowing of the leaves appears on the youngest leaves, and the older ones are not damaged. Zinc deficiency is the most common micronutrient.
Molybdenum is essential for the proper use of nitrogen from the soil. In its absence, nitrates accumulate in stunted leaves, and pale spots appear on them, especially along the edges of older leaves. Deficiency of this element occurs in acidic soils.
Importance of air and water for plants
Air and water provide the plant with hydrogen, oxygen and carbon. They are accessed from air and water, so they are not considered soil nutrients.
Carbon is the main building material of a plant, obtained mainly in the form of carbon dioxide from the air. Therefore, plants do not suffer from its deficiency.
Oxygen and hydrogen are the breathing gases of plants, which they receive in the form of water. During photosynthesis, it breaks down into oxygen and hydrogen, which plant cells use to obtain and use energy.
Healthy soil is important for providing plants with nutrients.
It is not always possible to solve this issue by adding fertilizers. The ability to absorb soil nutrients, even if they are abundant, is strongly affected by water, the presence of carbon, and soil structure.
How they are absorbed also depends on the pH value in the soil. Acidity or alkalinity, as well as ambient temperature, are just some of the factors that determine the extent to which nutrients are available to plants. Soil composition affects how well it retains nutrients and water. Clay and soil containing organic matter retain nutrients and water much better than sandy soils. From sandy soils, water runs off and carries away the nutrient content from the top layer, and becomes unavailable for use by plants. This state is called leaching.
Man-made man-made fertilizer is highly concentrated and the plant can absorb it directly without any conversion processes. If not dosed correctly, it can harm plants and the environment. Too much nitrogen fertilizer can lead to high levels of nitrate in the soil and accumulation in plants. Nitrates are converted to nitrites and can be harmful to health. Too much potassium and calcium prevents the absorption of other nutrients, and too much phosphorus prevents the absorption of nitrogen. So the best way is to fertilize sparingly and organically.