Calcium (Ca) is found all around us, and the very existence of plants and animals depends on it. Plants take up Ca as the Ca2+ cation. Once inside the plant, Ca functions in several essential ways.
Calcium deficiencies occur most often in acidic, sandy soils from which Ca leaches via rain or irrigation water.
Calcium helps balance organic acids within the plant as well as activates several plant enzyme systems.
Calcium helps form the compounds that make up part of cell walls, which in turn, strengthen the plant structure.
Calcium builds yields indirectly by improving root growth conditions and stimulating microbial activity, molybdenum (Mo) availability and uptake of other nutrients.
Calcium helps enable nitrogen (N)-fixing bacteria that form nodules on the roots of leguminous plants to capture atmospheric N gas and convert it into a form plants can use.
Calcium is a low-key essential nutrient that carries a heavy load in plant growth. Too often, it takes a backseat as soil fertility programs are developed for many high-yield and high-quality crops. Peanut and tomato growers are probably exceptions in their emphasis on good calcium nutrition.Learn More
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.