How to configure the nutrient solution for experiment?

  Concentrate preparation

  Process: calculation-weighing-dissolving-dispensing-saving.

  (1) Calculation: Calculate the dosage of various compounds in the formula according to the volume of the concentrate to be prepared and the concentration multiple.

  (2) Weighing: Weigh all kinds of fertilizers and place them in clean containers or plastic film bags, or on the plastic film flat on the ground to avoid loss. When weighing various salt fertilizers, pay attention to stability, accuracy, and speed. The weighing should be accurate to within plus or minus 0.1.

  (3) Fertilizer dissolution: Arrange the weighed fertilizers neatly and dissolve them separately after the final check. It is also possible to mix and dissolve the compounds that do not precipitate each other. Pay attention to the dissolution thoroughly, and stir while adding until the salt is completely dissolved.

  (4) Sub-packaging: the concentrated liquid is prepared into three concentrated liquids of A, B, and C, respectively, and filled in three liquid storage tanks. Tank A: Centered on calcium salt, all compounds that do not precipitate with calcium salt can be dissolved together; Tank B: Centered on phosphate, all compounds that do not precipitate with phosphate can be dissolved together; C Tank: Prepare the chelated iron solution in advance, and then dissolve the other various compounds required for the chemical C solution in small plastic containers, and then slowly pour them into the chelated iron solution, stirring while adding. The A, B, and C concentrated liquids are all added to the volume required for preparation according to the requirements of the concentration ratio, and the mixture is evenly stirred. The concentration multiple of the concentrated liquid should be determined according to the prescribed dosage of the nutrient liquid formula and the solubility of each salt, so as not to be too much.

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  is saturated and precipitated. The concentration factor should be an integer value, which is convenient for operation. It is generally 100 to 200 times higher than the balanced nutrient solution that plants can directly absorb, and the trace element concentrate can be concentrated to 1000 times.

  (5) Preservation: When the concentrated solution is stored for a long time, it should be acidified to prevent precipitation. Generally, it can be acidified with HNO3 to pH 3-4, and stored in a plastic container, in a cool and dark place.

  2.7.2 Preparation of working fluid

  2.7.2.1 Concentrate dilution

  The steps for diluting concentrate are:

  (1) Calculate the amount of liquid to be pipetted for various concentrates, and adjust the pH value of the water according to the requirements of the formula;

  (2) Inject 50 to 70% of the volume of the nutrient solution prepared in the storage tank or other container for the cultivation solution;

  (3) Measure A mother liquor and pour into it, start the water pump to circulate for 30min or stir to make it spread evenly;

  (4) Measure the mother liquor of B and slowly pour it into the clear water inlet of the storage tank, let the water source dilute the mother liquor of B and bring it into the storage tank to participate in flow and diffusion. The amount of water added in this process is 80% of the total liquid volume. ;

  (5) The mother liquor of C is diluted with water and brought into the reservoir to participate in the flow and diffusion. After adding enough water, circulate for 30 minutes or stir evenly;

  (6) Use a pH meter and a conductivity meter to detect the pH value and EC value of the nutrient solution, such as

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  Fruit determination results do not meet the requirements of the formula and crop, and should be adjusted in time.

  2.7.2.2 Preparation method

  (1) Calculate the required amount of various fertilizers according to the formula and the volume of the nutrient solution to be prepared, and adjust the pH value of the water;

  (2) Prepare C mother liquor;

  (3) Inject 50 to 70% of water into the reservoir or other container;

  (4) Weigh various compounds equivalent to the mother liquor of A, dissolve them in the container and pour them into the reservoir, turn on the water pump and circulate for 30 minutes;

  (5) Weigh various compounds equivalent to B mother liquor, dissolve them in a container, and dilute with a large amount of clean water, then let the water source dilute the B mother liquor and bring it into the storage tank, turn on the water pump to circulate for 30 minutes, and add water in this process To reach 80% of the total liquid volume;

  (6) After measuring the C mother liquor and diluting it, slowly pour it at the water source inlet of the reservoir, turn on the water pump and circulate until the nutrient solution is even;

  The seventh and eighth steps are the same as the concentrated solution dilution method.