What are the common nutrient solution formulas for hydroponic plants

Compared with soil-cultured plants, hydroponic plants have many advantages. Hydroponic plants are of good quality. Because the nutrient solution for flowers is formulated according to the growth needs of the flowers, the flowers cultivated are large and numerous, with a strong fragrance, bright colors, and a long flowering period. Hydroponic plants save nutrients, water, and labor. For hydroponic plants, you only need to regularly replenish the nutrient solution to the plants, which is simple to operate and saves labor and time. They are clean, free of weeds, and have few pests and diseases. Today, the editor mainly introduces two common nutrient solution formulas for hydroponic plants.

Preparation of nutrient solutions for hydroponic plants

1. Substrate preparation

The main role of the soilless cultivation substrate is to fix the flower plants in the container. Currently, the commonly used soilless cultivation substrates in China:

① Sand particles with a diameter of less than 3 mm.

② Natural gravel, pumice, volcanic rock, etc. with a diameter greater than 3 mm.

③ Vermiculite, a mica-type mineral with good buffering capacity that does not sink in water.

④ Perlite. It works better when mixed with mudstone and sand.

⑤ Peat with good air permeability and strong water-holding capacity can be used alone as a substrate or mixed with furnace slag, etc. In addition, furnace slag, bricks, charcoal, asbestos, sawdust, fern roots, bark, etc. can all be used as substrates. Substrates should be washed and disinfected before use.

2. Nutrient solution preparation

The various elements and their amounts used in preparing nutrient solutions for soilless cultivation of flowers should be determined according to the flower varieties being cultivated, their different growth stages, and different regions.

Hoagland nutrient solution formula

At present, there are many soilless cultivation nutrient solution formulas in the world. Most works on soilless cultivation collect many formulas. For example, Hewitt (1966) collected about 160 formulas. Some formulas have proven to be relatively good after decades of use. The Hoagland formula is also the most original one. Many places say that this was discovered by Hoagland himself in 1935, but that is actually not the case. It was published in 1933 after he and his research partners conducted a large number of comparative experiments. This is the most original classic formula, yet it is still in use today.

1. Nutrient solution formula: calcium nitrate 945 mg/L, potassium nitrate 607 mg/L, ammonium phosphate 115 mg/L, magnesium sulfate 493 mg/L, iron salt solution 2.5 ml/L, trace elements 5 ml/L, pH=6.0.

2. Modified Hoagland formula: calcium nitrate tetrahydrate 945 mg/L, potassium nitrate 506 mg/L, ammonium nitrate 80 mg/L, monopotassium phosphate 136 mg/L, magnesium sulfate 493 mg/L, iron salt solution 2.5 ml, trace element solution 5 ml, pH=6.0.

3. Iron salt solution: ferrous sulfate heptahydrate 2.78 g, disodium ethylenediaminetetraacetate 3.73 g, distilled water 500 ml, pH=5.5.

4. Trace element solution: potassium iodide 0.83 mg/L, boric acid: 6.2 mg/L, manganese sulfate: 22.3 mg/L, zinc sulfate: 8.6 mg/L, sodium molybdate: 0.25 mg/L, copper sulfate: 0.025 mg/L, cobalt chloride: 0.025 mg/L.

5. Precautions

① If used as a compound fertilizer, it can be prepared with natural water, omitting the trace element solution. If used as a soilless cultivation nutrient solution, it needs to be prepared with artificial soft water, such as distilled water, and the trace element solution must be added.

② The above nutrient solution is often prepared at 10 times or 20 times concentration, and then diluted when used. Note that the pH should be adjusted before use (different plants have different pH requirements, so it can be adjusted appropriately). In soilless cultivation, for crops to maintain normal growth and development, they must contain 13 essential elements, and all of them must be in a form that plants can absorb, that is, in an ionically dissociated state. In addition, the ratio between ions must also be appropriate. Only when the nutrient solution meets the above conditions is it possible for crops to develop well and achieve high yields. There are now hundreds of nutrient solution formulas published in the world, among which the Hoagland solution is the most famous and is widely used by nutrient solution experimenters and growers in various countries.