Nutrient solutions for hydroponics
Nutrient solutions for hydroponics are prepared by dissolving chemical salts in water that contain nitrogen, phosphorus, potassium, magnesium, calcium, sulfur, manganese, that is, macroelements, as well as boron, copper, zinc and other macroelements necessary for development.
In its composition, the nutrient solution should contain all the elements in ratios that do not exceed their consumption rate by plants. It should be remembered that for the normal development of most plants, the ratio is N = 0.5, P = 1, K = 2, Mg = 0.3. Plants absorb nutrients better from diluted solutions. At a concentration exceeding the optimum rate, plants may die.
The concentration of the nutrient solution may increase due to the fact that plants absorb water faster by the roots than mineral salts dissolved in it. In addition, the water partially evaporates, and this also leads to an increase in the concentration of the nutrient solution. It is especially important to monitor the nutrient solution in summer, when the evaporation of water in the vessels increases. It is necessary that the nutrient solution in the outer vessel is always at the same level, that is, filling it up to half of its volume. When the solution becomes smaller, it is added with water to its original volume: in summer it is usually added after 2-3 days, in winter less often.
The reaction of the solution is of great importance for the normal growth and development of plants. The nutrient solution for plants grown without soil, depending on the crop, should be 5.5-7.0. A shift in the reaction of the solution to the alkaline side (pH above 7) negatively affects the plants; in such a solution, the salts of iron, magnesium, calcium, phosphorus and manganese are converted into insoluble compounds that plants cannot assimilate. Sometimes changes in the composition and concentration of the solution are insignificant, but, nevertheless, they can adversely affect the development of plants. In this regard, it is necessary to periodically determine the acidity of the solution. The prepared solution can be stored in a sealed container for 2-3 months.