icons-resources-agrisight icons-resources-article icons-resources-business icons-resources-fertilizer icons-resources-macronutrients icons-resources-micronutrients icons-resources-nutrient icons-resources-soil icons-resources-video

Potassium (K) is one of the essential nutrients and is taken up in significant amounts by crops. Potassium is vital to photosynthesis, protein synthesis and many other functions in plants. It’s classified as a macronutrient, as are nitrogen (N) and phosphorus (P). Plants take up K in its ionic form (K+).

Quick Facts

Potassium enhances many enzyme actions aiding in photosynthesis and food formation. It builds cellulose and helps translocate sugars and starches. Potassium is vital to producing grains rich in starch.

Quick Facts

Potassium maintains turgor and reduces water loss and wilting.

Quick Facts

Potassium is known as the "quality nutrient" because of its important effects on factors such as size, shape, color, taste, shelf life, fiber and other quality-related measurements.

Quick Facts

In many high-yielding crops, the K content in the plant is comparable to the nitrogen (N) content.

Quick Facts

Potassium is absorbed by plants in the ionic form, indicated as K+.

Quick Facts

Plants deficient in K are less resistant to drought, extreme temperatures and other stressors. Plants lacking K are also more susceptible to pests, diseases and nematode attacks.

Quick Facts

Ample K can increase root growth and improves drought tolerance.

Dig Deeper: Fertilizer Use Guide

Potassium is essential in nearly all processes needed to sustain plant growth and reproduction. Plants deficient in potassium are less resistant to drought, excess water, and high and low temperatures. They are also less resistant to pests, diseases and nematode attacks. Because potassium improves the overall health of growing plants and helps them fight against disease, it is known as the "quality" nutrient. Potassium affects quality factors such as size, shape, color and vigor of the seed or grain, and improves the fiber quality of cotton.

Learn More

Deficiency Symptoms

Symptoms of deficiency can vary across crop species, but similarities exist for how nutrient insufficiency impacts plant tissue color and appearance. Nutrient deficiencies are commonly associated with the physical location on the plant (i.e., whether the symptoms are primarily observed on older versus newly formed plant tissue), but these symptoms can spread as the severity of the deficiency progresses.

All photos are provided courtesy of the International Plant Nutrition Institute (IPNI) and its IPNI Crop Nutrient Deficiency Image Collection. The photos above are a sample of a greater collection, which provides a comprehensive sampling of hundreds of classic cases of crop deficiency from research plots and farm fields located around the world. For access to the full collection, you can visit IPNI's website.