What are the functions of potassium fertilizer? A detailed explanation of the important benefits of potassium fertilizer for crops

Potassium is one of the three major fertilizer elements. In plants, potassium generally accounts for 0.2% to 4.1% of dry matter weight, second only to nitrogen. During plant growth and development, potassium participates in the activation of more than 60 enzyme systems, photosynthesis, transport of assimilates, carbohydrate metabolism, and protein synthesis.

The main functions of potassium fertilizer

Applying potassium fertilizer can promote crop photosynthesis, promote crop fruiting, and improve crop cold resistance and disease resistance, thereby increasing agricultural yield. The potassium element exists in plants in the form of free potassium ions. It can promote the metabolism of carbohydrates and nitrogen; control and regulate the activity of various mineral nutrients; activate the activity of various enzymes; control the transport of nutrients and water; and maintain cell turgor pressure, thereby preventing plants from wilting.

1. Promoting enzyme activation. The activation of enzymes is one of the most important functions of potassium during plant growth. It has now been found that potassium is an activator of more than 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.

2. Promoting photosynthesis and the transport of photosynthetic products

① Improving photosynthetic efficiency.

② Regulating the opening and closing of stomata and controlling the entry and exit of CO₂ and water.

③ Promoting the synthesis of carbohydrates and accelerating the flow of photosynthetic products.

3. Promoting protein synthesis

① Promoting the uptake and transport of NO₃, a key component of protein synthesis.

② Being closely related to the protein synthesis process.

4. Enhancing plant stress resistance. Potassium can reduce soluble amino acids and monosaccharides in crops, increase cellulose, and thicken cell walls; potassium accumulation in the crop root system produces an osmotic pressure gradient that can enhance water absorption; under drought and water shortage conditions, potassium can cause crop leaf stomata to close to prevent water loss. Therefore, potassium can enhance crops' resistance to disease, cold, drought, lodging, and salt.

5. Improving crop product quality, increasing the protein content of grain crops, the crude fat and palmitic acid content of oil crops, and the starch and sugar content of tuber crops and sugar crops; increasing the fiber length, strength, and fineness of fiber crops and cotton; adjusting the sugar-acid ratio of fruit and increasing its vitamin C content; improving the shape, size, color, and flavor of fruits and vegetables, and enhancing their storability.

The harms of excessive application of potassium fertilizer

1. Excessive application of potassium will not only waste precious resources, but also reduce crop uptake of cations such as calcium and magnesium, causing “heart rot” in leafy vegetables and “bitter pit” in apples.

2. Excessive application of potassium fertilizer will cause soil environmental pollution and water pollution.

3. Excessive application of potassium fertilizer will weaken crop production capacity.