Benefits of potassium in fertilization

It is very likely that you already know that Potassium (K) is a nutrient absorbed by plants in large quantities and that, together with Nitrogen (N) and Phosphorus (P), they are the elements most applied in fertilizers annually. But it is not just the amount used by crops that makes it important for Plant Nutrition. See some examples of the importance of K in fertilizers!

• Unlike the other primary macronutrients – Nitrogen and Phosphorus – Potassium does not form organic compounds, which makes it very mobile within plants. It is available in the soil in ionic form (K+) and enters the roots together with the water absorbed by the plants.  

• But Potassium's affinity with water doesn't stop there. After entering through the roots and moving to the stems and leaves, potassium plays a fundamental role in the way plants control water intake. Stomata are tiny structures that are mostly found in leaves and whose function is to control the entry of carbon dioxide and the exit of oxygen and water vapor (transpiration) in plants. Without potassium, these stomata do not function properly, causing them to either open or close partially or more slowly, making water absorption difficult and damaging other processes such as...

• ... photosynthesis! Plants deficient in potassium have a reduction in photosynthesis - which is the process of energy production by plants. As plants produce less energy, they begin to breathe more intensely to survive and end up using up their energy reserves, which are sugars and oils. And, as you may have suspected, if the plant is deficient in potassium and consuming its reserves, its production and productivity tend to decrease.

• And speaking of reserves, potassium plays a very important role in the transport of sugars within plants. During photosynthesis, carbon dioxide, water and nutrients are transformed into sugars in the leaves. And potassium is responsible for transporting a large part of these sugars and other products from the leaves to reserve organs such as grains, fruits and roots. In other words, without potassium, in addition to the plant producing less and using more energy, it also has greater difficulty transporting and storing these sugars.

• Potassium, in addition to the nutritional benefits already discussed above, generates other very important benefits for plants such as tolerance to cold, pests and diseases. In the case of cold tolerance, adequate potassium levels mean that the water inside the plants does not freeze at lower temperatures. This way, in less severe cases, there is no ice formation inside the plants and they are able to better tolerate the cold with less impact on metabolism. In the case of diseases, it is important to remember that potassium regulates the entry of water into plants. When they are well “hydrated”, the surface of their leaves become more rigid, which makes it difficult for diseases such as fungi and bacteria to enter or even for insect bites (pests) to penetrate.

But it is important to remember that, as critical as the application of potassium to crops is, a balanced supply of this nutrient is essential for the success of fertilization. The use of very important decision tools such as soil analysis, leaf analysis and the history of the area can make potassium yield more and better!