The need for plants in nutrients
The need for nutrients( especially - in microelements) in different plants is not the same.
In all cases, the element indispensability rule applies, especially with regard to macro elements. If there is not enough nitrogen, for example, there is no point in adding magnesium or sulfur instead of phosphorus instead. Even if it is known that the macronutrients nitrogen, sulfur and phosphorus are components of the protein, do not forget that the protein consists of different amino acids and the absence of any of them will not allow it to exist as such: it will produce a completely different protein that plays a different role in plant life.
It would seem that now the time has come to indicate the dosage of nutrients necessary for the plant, but. .. it should not be forgotten that most of these substances are present in the soil. Not knowing what and how much is not enough and there is a shortage at all, do not rush to fill up the green pet with fertilizers.
To know the approximate content of nutrients in the soil, it is not necessary to use the services of a chemical laboratory. It is enough to take a close look at the type of plants and remember the symptoms of a lack or excess of each of the elements. It is possible and specially planted in the soil, so to speak, a test plant - a tomato, as many of the ornamental plants have a "non-standard" color of leaves and stems, and therefore, an atypical reaction, and the reactions of this sensitive vegetable are well studied and very visible.
Nitrogen. With a lack of nitrogen, the development of the plant slows down, the color of the leaves becomes pale, in extreme cases - yellow and even brown, the buds are showered. In a tomato, the veins of the leaves become purple-reddish, the stems are thin, hard and fibrous.
With excess nitrogen, the leaves are dark green, saturated color, shoots grow intensely, but flowering is delayed almost more than with a shortage - for flowers, the factor is not unimportant. In ornamental plants with variegated leaves, the original color may disappear: they will turn green entirely.
The least amount of nitrogen is required by beans.
Phosphorus. The defect of this element becomes noticeable already at the seedling stage. It is characterized by small dark colors( often with a violet hue) leaves. The tomato cotyledons grow up in the tomato, their lower sides are violet-red, the leaves are folded( with normal phosphorus content in the soil of the cotyledon oriented horizontally, and the leaves unfold).
The general development of the plant is also delayed.
Excess phosphorus leads to chlorosis, as it adversely affects the absorption of iron. It can be indirectly calculated according to the state of annual plants - their main undesirable effect is noticeable on them: rapid, premature aging.
Potassium. If this element is deficient, the plants will be short and sluggish, the leaves will be brittle, their edges usually begin to spin up, the tissues become brown and die. The tomato reacts by the appearance on the leaves of bronze spots, turning into a continuous brown border of dead tissue. Excess potassium leads to a deterioration in the color of flowers, the appearance of shortened peduncles;with excess potassium, the lower leaves often turn yellow.
Calcium. For lack of calcium is characterized by dwarf growth of plants and death of the upper nits. The roots become thick and short, covered with mucus.
Sulfur. From the lack of sulfur, the leaves and their petioles become snow-white, the stems are lengthened, but the plant as a whole has a clearly unhealthy appearance.
Magnesium. For lack of magnesium, as well as for the lack of some other nutritional elements, chlorosis is typical, but its development and symptoms are somewhat different. On the lower sides of the leaves, the tissue between the veins turns pale, although in the immediate vicinity of them( in contrast to the case with a lack of nitrogen, when the yellowing and blanching seem to diverge from the veins) remains green longer. This phenomenon is sometimes called the "marbling of the leaves".With a large deficit, the color reaches white. At tomatoes on leaves the upper unpaired lobe pales.
Iron. Chlorosis with iron deficiency begins with the top point of plant growth, after blanching in special cases, the upper shoots become brown and die.
Manganese. Its lack can be diagnosed by the condition of young leaves: they are very small and covered with yellow spots, in the most neglected cases the tissue before dying not only turns brown, but becomes transparent.
Bor. With its lack of chlorosis, and then necrosis begin to develop near the base and along the edges of young leaves, which subsequently die. Characterized by blackening and mucosal apex buds( in tomatoes, in addition, noticeably strong branching of lateral shoots).
Copper. With the problem of lack of copper are rare, but it can happen., If the site is located on a marshy ground. House plants, as a rule, do not threaten if the flower does not grow on almost pure peat of marsh origin. There is even a special term, giving the name of copper "malnutrition" - a disease of development. The stems become rigid and thin with it, the leaves also become thinner and become covered with yellow-green spots. The leaves of tomatoes become dark blueish-greenish, brittle.
Zinc. The lack of zinc will signal the appearance of grayish leaves. The leaves gradually acquire a bronze or yellow-brown hue, and their edges become brown.
Warning! Similar symptoms in houseplants can also appear for other reasons:
• The plant looks oppressed, its leaves fade and turn yellow in low light.
• Leaves tips may dry up due to insufficient humidity.
• Grinding of leaves and slowing down of growth can be explained by the fact that the pot is too small for the plant( as a rule, the roots get out on the surface or through the bottom opening of the pot).
• Light spots on the leaves may appear due to spraying with hard water. They will safely disappear if they are washed away.
Individual disease responses of different plant species to nutritional deficiencies will be mentioned later. If you can exclude all other reasons - choose the right fertilizer.