How to prepare nutrient solution for eggplant soilless seedling raising?

There are two basic methods of soilless seedling: substrate seedling and nutrient solution seedling. Generally, nutrient solution is needed. Nutrient supply at seedling stage is closely related to the growth and quality of seedlings, so it should be scientifically selected and allocated. The nutrient solution for eggplant soilless seedling can be prepared by soilless culture, such as Japanese garden test formula and Yamazaki formula, and the concentration is1/4 ~1/2 of the standard concentration; You can also choose a special formula for seedling raising. The formula of eggplant soilless (substrate) seedling nutrient solution is as follows:

① Add 400-500g urea, 450-600g potassium dihydrogen phosphate, 500g calcium sulfate and 500g magnesium sulfate into 1000kg water. The formula of this nutrient solution contains a variety of macronutrients required by eggplant seedlings, and it is suitable for various soilless seedling raising methods of eggplant, especially when seedlings are raised by hydroponics, or when gravel, gravel, slag, vermiculite, perlite, carbonized chaff and other materials are used as substrates. However, the preparation cost of its nutrient solution is high, so it is not necessary to adopt this formula when the nutrient content in the matrix is high.

② Add 400-500g urea and 450-500g potassium dihydrogen phosphate into 1000kg water. The formula only provides nutrient solution of three major elements, namely nitrogen, phosphorus and potassium, and is suitable for the organic substrate seedling raising method with less nutrient content in the substrate.

③ Add 400-500g potassium dihydrogen phosphate and 600-700g ammonium nitrate into 1000kg water. The formula is suitable for the organic substrate seedling raising method with less nutrient content in the substrate.

④ 500g of magnesium sulfate, 320g of ammonium nitrate, 8g of potassium nitrate, and 550g of calcium superphosphate are added into1000kg of water. The scope of application of this formula is the same as ①.

The above formula does not include trace elements needed in plant growth. If hydroponics is used to raise seedlings with vermiculite, perlite, crushed stone and carbonized chaff as substrates, the following trace elements must be added. That is, 3g of boric acid, 0.22g of zinc sulfate, 2g of manganese sulfate, 3g of sodium sulfate and 0.05g of copper sulfate are added to the above 1000kg solution. Nutrient solution for soilless seedling raising should be as easy to buy as possible, cheap, simple to prepare, complete in nutrients and safe to use. Trace elements can be removed from the nutrient solution when the content of organic substrates such as peat and waste culture materials of edible fungi is high.

After the above nutrient solution is prepared, it cannot be directly used for watering seedlings, and the pH value of the nutrient solution must be adjusted. The pH value of nutrient solution suitable for eggplant growth is 6.0 ~ 6.5. If the pH value of the prepared nutrient solution is too high or too low, sulfuric acid, hydrochloric acid, potassium hydroxide and sodium hydroxide must be selected for adjustment. In addition, we should also pay attention to control the temperature of nutrient solution at 20 ~ 25℃, so as not to cause the tomato rhizosphere temperature to be too high or too low.