Like all other living things, plants need enough nutrients to survive. These are absorbed through the roots with the water. However, the plants cannot look for these nutrients themselves, but have to make do with what the soil has to offer. Therefore, it is important to fertilize and to be sure, enough, not excessively and correctly. Not every nutrient is suitable for every plant or every time.
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Important plant nutrients
No plant can survive and grow without supplied nutrients. Since these can only be taken up from the soil with the irrigation water via the roots, they must be supplied regularly. Because if the soil is exhausted, growth stops until the plant dies. But not every plant needs the same nutrients in the same amounts. The timing of the gift is also important. Some help growth and an abundance of flowers and fruits, while others strengthen the plant for the winter. And too many plant nutrients can also damage and prevent growth. The plant nutrients are 13 elements that the plants need to live. These are divided as follows:
- Macronutrients (main nutrients)
- Micronutrients (trace nutrients)
Macronutrients (main nutrients)
As the main nutrients, the macronutrients must be administered to the plant in relatively high quantities so that they can grow and thrive healthily. It is also the case here that every plant needs all of these main nutrients. A deficiency of just one of these nutrients can therefore lead to damage to the plant. The macronutrients have already been researched and it is known which symptoms a possible deficiency or excess can cause. Therefore, a sufficient supply and presence in the soil of the following nutrients should always be ensured:
Calcium (Ca)
Calcium is required for the stiffening of the cell walls and promotes and supports the stability and functionality of the cell membrane. As a rule, there is sufficient calcium in the garden soil for the needs of the plants. Only very acidic soils can suffer from a calcium deficiency. Deficiency and eventual excess affect the plants as follows:
- Deficiency leads to chlorosis
- growth disturbances, especially in young leaves
- Avoid excess potassium and magnesium
- leads to calcium deficiency
- Wood construction is preferred to fruit growth
- Excess leads to other deficiency symptoms
- Magnesium, potassium and phosphorus are reduced
Potassium (K)
Potassium is an important nutrient, as it is for us humans, for regulating the water balance in plants. It is usually found as a free ion in the cells and regulates the osmotic pressure here in order to open or close the stomata. If there is a lack of potassium, the water balance is disturbed and the leaves hang limp and withered. Plants that are well supplied with potassium are protected as follows:
- with high potassium content increased salt concentration
- promotes the frost resistance of a plant
- Photosynthesis is promoted
- promotes transport of sugar, cellulose and starch
- good resistance to pests and diseases
Magnesium (Mg)
Magnesium is a central building block of chlorophyll. About 30% of the magnesium is found here in the leafy green. The nutrient is important for many metabolic processes in plants. Deficiency and excess of magnesium can show up as follows:
- in case of deficiency metabolic disorders
- leads to yellowing of the leaves
- Leaf veins remain green
- Deficiency is rare
- Surplus also rare
- Symptoms resemble calcium deficiency
- growth inhibited
- damaged roots
Phosphor (P)
Phosphorus is an important element for the cell structure, membrane and function of a plant. In addition, this nutrient is involved in all metabolic processes. Without phosphorus, plants are more susceptible to diseases of all kinds. If a plant suffers from a phosphorus deficiency, it will grow stunted. The older leaves are dark in color. If this deficiency lasts longer, the leaves will turn red and die. However, there is rarely a phosphorus deficiency in local gardens, since most soils are actually oversupplied with phosphorus. An excess does not have a negative effect, since phosphate must first be dissolved before it can be absorbed.
Sulfur (S)
Sulfur is required primarily for the formation of proteins and vitamins and is important for the chlorophyll balance. In addition, absorbed nitrate is reduced, which supports and promotes the utilization of absorbed nitrogen. Sulfur is taken up from the soil by the plant in the form of ions. Since sulfur occurs in a wide variety of forms and traffic and industry also release sulfur, there is usually always enough of it. If the nutrients have to be supplied, horn meal should be used as fertilizer, for example. However, if the soil is over-fertilized, it can quickly become acidic. Deficiency and excess show up on the plants as follows:
- Deficiency results in thin, woody stems
- young leaves turn light yellow
- is due to reduced formation of chlorophyll and chloroplasts
- no direct damage from excess
- Damage due to acidic soil formed
nitrogen (N)
Nitrogen is important for the growth of leaves and shoots of a plant because it is involved in the formation of chlorophyll and enzymes. It is therefore particularly important that the plants receive nitrogen, especially in the spring when they sprout. Later in the year the dosage should be reduced or stopped altogether. Because if you still fertilize with nitrogen in autumn, then many plants will form new shoots that can no longer stabilize before winter, which could then lead to frost damage. In addition, not too much of this nutrient should be administered, because an excess can be just as harmful as a deficiency. The signs of deficiency or excess can be recognized as follows:
- poor growth when there is a shortage
- small and bright leaves
- bad rooting
- smaller fruits
- other trace elements can be poorly absorbed
- Excess very dark green leaves
- thin, long and weak shoots
- more susceptible to diseases and pests
- poor shelf life of the fruit
Micronutrients (trace nutrients)
The trace nutrients are also essential minerals that the plants need for healthy growth, but usually only in small amounts. When the soil is organically fertilized, these nutrients are usually present in sufficient amounts because they are found in plant tissue. Therefore, if a garden soil is always supplied with compost, the minerals should also be sufficiently available. The research is not yet ready to say how important these individual nutrients are for the plants and what they do. The fact is, however, they are more or less needed. Important micronutrients include the following:
Boron (B)
If the soil is very sandy, this can quickly lead to a boron deficiency. Then the plants grow poorly and remain relatively small. Because boron is particularly important for cell stretching and cell division and has a positive effect on carbohydrate metabolism.
Chlor (Cl)
The types of cabbage in a kitchen garden in particular need chlorine as chloride. If there is a lack of chlorine, this can be compensated for with a teaspoon of table salt per square meter. However, raspberries, tomatoes, potatoes, cucumbers and beans must not be supplied with chlorine from the salt, otherwise they will suffer from chlorosis.
Iron (Fe)
Iron is an important nutrient for plants to form seeds and germs. It is also involved in photosynthesis. A lack of iron always leads to chlorosis. As a rule, the iron nutrients in the garden soil are sufficiently available. However, lime and waterlogging can lead to an iron deficiency, which can weaken the plant.
copper (Cu)
Copper is one of the important components for photo and protein synthesis, because it activates the enzymes and promotes flowering. If the plant suffers from a copper deficiency, the following symptoms can occur:
- young leaves die off
- stunted growth of flowers
- therefore less fruit
- and fewer seeds
Note: There is usually a copper deficiency in very sandy and calcareous soils. To prevent this, you should never water with calcareous tap water, but ideally use collected rainwater.
Manganese (Mn)
Manganese is particularly important for the hormonal balance of plants. In addition, the administration of manganese promotes protein synthesis and activates enzymes. However, a lack of manganese can cause the following:
- promotes chlorosis
- roots underdeveloped
- growth disorders
- low frost resistance
Molybdenum (Mo)
Molybdenum is important for the metabolism of the plant and the activation of enzymes. Because a deficiency can cause chlorosis, leaf deformities, necrosis and an overall reduced growth. The deficiency symptoms usually appear at a low pH value of less than 5, which is equivalent to an acidic soil.
Zinc (Zn)
Zinc is required for plant metabolism. If a plant is optimally supplied with zinc, then optimal seed and pollen quality is guaranteed. As a rule, there is hardly any zinc deficiency in the garden soils here. If it still occurs, then it is because the soil has been limed too much and the pH value is over 7. If there is a deficiency, the following symptoms appear:
- Chlorosen
- inhibited growth
- necrosis
- high susceptibility to pests and diseases