Potassium fertilizer, also known as potassium fertilizer. Fertilizers with potassium as the main nutrient generally contain 0.2% to 4.1% potassium by dry matter weight in plants, second only to nitrogen. Potassium is involved in the activation of over 60 enzyme systems, photosynthesis, transport of assimilates, carbohydrate metabolism, and protein synthesis during plant growth and development.

Classification of Potassium Fertilizer

The effectiveness of fertilizer depends on its potassium oxide content. There are mainly potassium chloride, potassium sulfate, plant ash, potassium salts, monopotassium phosphate (monopotassium dihydrogen phosphate), etc. Most of them can dissolve in water and have a fast fertilizing effect. And it can be absorbed by the soil and is not easily lost. When potassium fertilizer is applied in moderation, it can make crop stems grow strong, prevent lodging, promote flowering and fruiting, enhance drought resistance, cold resistance, and resistance to pests and diseases. A unit fertilizer with a specified amount of potassium (K or K2O) is called potassium fertilizer.

Production method of potassium sulfate

One is to directly produce it from natural minerals and hard salt mines. The second is obtained by converting potassium chloride, and 70% of the world’s produced potassium sulfate is produced by conversion method. Potassium sulfate contains 50% to 54% potassium oxide, and relatively pure potassium sulfate is white or light yellow. Diamond or hexagonal crystals, with much lower hygroscopicity than potassium chloride, good physical properties, less prone to clumping, and inexpensive application.

The application of potassium fertilizer depends not only on the potassium supply capacity of the soil, but also on factors such as crop types, agricultural production levels, climate, and soil conditions. The content, form, transformation, and potassium supply capacity of potassium in soil are important criteria for the rational allocation and application of potassium fertilizer. The total potassium content of soil varies greatly, generally ranging from 0.1% to 3%, with an average of about 1%.

Potassium in soil includes three forms:

① Mineral potassium. It mainly exists in the coarse-grained part of soil, accounting for about 90% of total potassium, and is extremely difficult for plants to absorb Slow acting potassium. It accounts for about 2% to 8% of total potassium and is a source of rapid release of potassium in soil.

③ Quick acting potassium. Refers to the exchangeable potassium adsorbed on the surface of soil colloids and potassium ions in soil solutions. Plants mainly absorb potassium ions from soil solutions. The potassium nutrient level of plants during the season is mainly determined by the content of available potassium in the soil. The content of quick acting potassium generally accounts for only 0.1% to 2% of total potassium, and its content is not only affected by cultivation, fertilization, etc., but also controlled by soil slow-release potassium storage and conversion rate.

Effect

Promoting enzyme activation is one of the most important functions of potassium in plant growth, and potassium has been found to be an activator of over 60 enzymes. Therefore. Potassium is closely related to many metabolic processes in plants, such as photosynthesis, respiration, and the synthesis of carbohydrates, fats, and proteins.

Agricultural applications

If crops lack potassium fertilizer, they will suffer from “soft bone disease”, prone to lodging, and often plagued by pathogens and pests. Potassium is often referred to as the “quality element”. Its main effects on the quality of crop products are:

① Can promote crops to better utilize nitrogen, increase protein content, and promote the production of sugar and starch;

② Make the nucleolus, seeds, fruits, tubers, and tubers larger, with a beautiful shape and color;

③ Improve the oil content of oil crops and increase the content of vitamin C in fruits;

④ Accelerate the ripening of fruits, vegetables, and other crops to achieve a consistent maturity period;

⑤ Enhance the product’s resistance to collision damage and natural decay, and extend the storage and transportation period;

⑥ Increase the strength, length, fineness, and color purity of fibers in cotton and hemp crops. Potassium can enhance crop stress resistance, such as drought resistance, cold resistance, lodging resistance, and resistance to insect and pest invasion.

Application method

Potassium fertilizer can be used as a base fertilizer, as well as a topdressing. Some varieties can also be used as foliar fertilizer, but the application effect of base fertilizer and foliar fertilizer is better. Using potassium fertilizer as a base fertilizer can meet the potassium demand of crops throughout their entire growth period, especially for crops with short growth periods and soils with obvious potassium deficiency. For crops with long growth periods such as cotton, a combination of basal application and foliar spraying can be used. A combination of basal and topdressing can be used for sandy soil.

The mobility of potassium in soil is between nitrogen and phosphorus. When the available potassium content in soil is less than 100 milligrams per kilogram per acre, it is sufficient; When the soil available potassium content is below 100-150 mg/kg, applying K2O3 3% -5 kg/mu is sufficient. When the soil available potassium content is greater than 150 mg/kg, chemical potassium fertilizer may not be applied or applied less depending on the crop type.