We Explain Why It Is Important To Properly Prepare A Fertilizer Solution

2023 Author: Ava Durham | [email protected]. Last modified: 2023-11-27 07:13

Plants are complex and whimsical creatures with their own needs and structural features. For each of them there is a specific approach and environment in which growth will take place in a comfortable environment. But, unfortunately, the soil or water in the environment of your wards does not always meet the requirements. Do not immediately give up with tools - plant food comes to the rescue. Many difficulties with the environment are solved by competent care. Read about how to correctly calculate and apply fertilizers in the constant question-answer section.

Question: with what concentrations of fertilizer solutions can plants be sprayed and / or watered under the root?

Answer: In addition to fertilizing when planting or digging the soil, it is widely used in professional and amateur practice to fertilize various crops by irrigation under the root (root dressing) or by spraying the leaf surface (foliar dressing).

Root dressing is used on all crops. Combining fertilization with irrigation, it is convenient to control the development of plants and compensate for the lack of soil fertilizers.

The root system absorbs nutrients only from weak solutions with a concentration of 0.01-0.05% (1-5 g per 10 liters of water). The usual concentration of soil solution ranges from 0.02-0.2% (2-20 g per 10 liters of water). Therefore, plant growing technologists always advise to carry out preliminary and subsequent watering of the fertilizing area at average recommended doses for water-soluble fertilizers from 10 to 30 g per 10 liters. water. Or feeding should be done in well-moistened soil. Usually this technique is ignored due to lack of water or time. If you feed the plant with a solution of this concentration in dry soil, you can harm the root system - make it a chemical burn.

Modern plant physiologists have determined quite a lot of methods and mechanisms for the absorption of nutrients by the root and vegetative parts of the plant - ion-cation exchange, various types of diffusion, pinocytosis, etc. (Yurin V. M. Plant Physiology: textbook / V. M. Yurin. - Minsk: BSU, 2010. - 455, p. 269) We will not consider all the mechanisms, but the method of absorption of solutions from the soil and its propagation along the apoplast remains undoubted and significant (an apoplast is a system of interconnected cell walls, through which most of the water and substances dissolved in it are transported in the plant), thanks to osmosis (fig. 1).

Osmosis is a phenomenon in which any system of solutions (water + mineral / organic substances) strives for equilibrium by mixing them - a weaker solution tries to dilute a more concentrated one.

A vegetative plant is 70-95% water. Each cell is filled with a solution. If the concentration of the solution inside the cell is higher than the concentration of salts outside it, then water from the apoplast will penetrate through the membranes into the cell. If on the contrary, the water from the cell will tend to come out.

In practice, it looks like this, if you watered the plant with fertilizer in a higher concentration of solution than recommended in the instructions (for example, not 20 g, but 200 g per 10 liters of water), then a solution with a higher concentration is formed in the soil cells of the root system and then, according to the law of osmosis, weaker solutions inside the cells will try to dilute the external environment, producing dehydration of the plant. Visually, we will see his oppression with possible subsequent death. The way out in this case is the operational shedding of the soil with a large amount of water.

Due to the mechanism of water evaporation from the surface of the leaves (transpiration), a strong negative pressure is created in the upper part of any plant, which forces the water to move from bottom to top.

The osmotic concentration of vacuolar juice for root cells is 0.3-1.2 MPa, and for cells of aboveground organs - 1.0-2.6 MPa. This determines the existence of a vertical gradient of osmotic concentration and sucking force from roots to leaves (Polevoy V. V. Plant Physiology: textbook for biol. Specialist universities. - M.: Vyssh.shk., 1989. - 464 p., P. 191).

Thus, osmosis manifests itself more strongly at the points of growth of the vegetative part of plants. Therefore, if we can give a solution of a higher concentration to the leaf than under the root, but less than the concentration of solutions inside the cells, then we will not violate the law of osmosis and will provide the plant with additional nutrition, bypassing the root system.

Welcome to Foliar (foliar)

Foliar dressing is a new tool in the gardener's arsenal. It allows you to correct the development of the plant as a result of any unfavorable growth conditions (heat, frost, prolonged rains or drought, etc.), to give additional development energy and even save the crop.

Foliar dressing can be different

If you water the plant from a watering can with the condition that the solution hits the leaves (not strictly under the root), then this is also, in part, foliar feeding, then the concentration of the solution should be no higher than 1-2 g / l. At this concentration, the root system will absorb nutrients from the solution.

If you use a fine sprayer for foliar dressing, then you can make a solution concentration of 10-20 g / l, provided that the solution does not drain in large quantities under the root, since such a concentration will already be destructive for the roots.

Of course, it is worth considering the factor that young plants are more sensitive to the concentrations of solutions for irrigation and spraying. Therefore, seedlings and young plants should be treated with the lowest suggested concentrations. It is necessary to do foliar treatments at the right time - early in the morning or late in the evening during a period of weak solar activity. If the weather is cloudy, then spraying and watering can be carried out during the day.