1, potassium nitrate

It contains 13.5% nitrate nitrogen and 46% potassium. It is a chemically neutral and physiologically neutral fertilizer with good water solubility, and long-term application will not lead to soil acidification.

It is suitable for young fruits of vegetables and fruit trees from the expansion stage to the early coloring stage, and can promote the expansion of pulp cells. Because it contains nitrate nitrogen, it is not recommended to use it in the later stage of coloring, which may easily lead to green.

2. Potassium dihydrogen phosphate

It contains 52% phosphorus and about 34% potassium. It is a chemically neutral and physiologically neutral fertilizer with good water solubility. Generally, before and after flowering, it can be used to promote root germination and flower bud differentiation and provide energy for flowering and fruit setting.

Application in coloring period can promote flour coloring and increase fruit sweetness; The use of fruits after picking can promote the aging of branches and improve the degree of lignification of fruits.

3. Potassium chloride

The appearance of potassium chloride is white or light yellow crystal, and the iron salt is red. Soluble in water, it is a high concentration and quick-acting potassium fertilizer. It can be used as base fertilizer and topdressing. The amount of base fertilizer is 8 ~ 10 kg, topdressing is 5 ~ 7 kg, and foliar spraying is 0.5% ~ 1%.

The scope of application is correspondingly smaller than that of potassium sulfate. Special attention should be paid to the use of chlorine-sensitive crops such as watermelon, grapes and potatoes to avoid "chlorine damage".

In addition, potassium chloride is not suitable for saline-alkali soil, but chloride ion in potassium chloride can promote photosynthesis and fiber formation, especially for fiber crops such as hemp.

4. Potassium sulfate

The appearance of potassium sulfate is white crystals or colored crystals or particles. The content of potassium is 54% in theory and 50% in general. It is a chemically neutral and physiologically acidic fertilizer with good water solubility. It is characterized by low hygroscopicity, not easy to agglomerate during storage and easy to dissolve in water.

It is suitable for all kinds of crops, and can be used as base fertilizer, topdressing and topdressing outside the roots. Generally, the amount of base fertilizer per mu is 10 ~ 12 kg, the amount of topdressing per mu is 5 ~ 7 kg, and foliar spraying is 0.5% ~ 1%.

Potassium can generally be absorbed by the soil and will not be lost, but the measure of "small amount and more meals" should also be taken in sandy soil with poor fertilizer conservation ability, and the application effect is the best on potassium-loving crops such as potatoes and melons.

5. Potassium humate

It is a slow-acting organic solid potash fertilizer with strong fertility and alkalinity. Because it contains humic acid with strong biological activity, it has very strong adsorption, complexing and chelating properties.

It can promote crops to absorb and utilize potassium more effectively, and has a good effect on activating soil and promoting crop growth and resistance.

In particular, compound potassium humate can provide crops with a variety of nutrients such as nitrogen, phosphorus, potassium, organic matter and trace elements, and can be widely used as base fertilizer, topdressing and foliar spraying fertilizer for various crops.