Calcium is a secondary nutrient that is critical to crop development. It is needed in large amounts by all plants for the formation of cell walls and cell membranes, and it plays a vital role in soil structure, according to an article on HelenaChemical.com. Due to the immobility of calcium in the soil and plant tissues, a continuous supply must be present for plants to access.
Calcium is only xylem mobile, meaning it can only move up the plant, and once in place, it cannot be remobilized and moved to new developing tissues. Young developing tissues such as growing points and fruiting bodies tend to be affected the most once soil reserves are depleted. Because of calcium’s low mobility in the plant, we can see calcium deficiency even in soils with high calcium levels. Symptoms of deficiency include death of growing points, premature shedding of blossoms and buds, tip burn, blossom end rot and bitter pit. Without proper levels of calcium, shelf life of fruits such as cantaloupes and tomatoes can be reduced significantly.
Soils with adequate amounts of calcium tend to be more friable and have better water infiltration properties. This is because calcium displaces sodium in the soil, and with adequate leaching irrigations, it can help improve overall soil quality. Soils that have high sodium and low calcium become sodic and do not allow for good water penetration. In these situations, it is important to add calcium with large amounts of gypsum or lime depending on other factors of soil chemistry. Calcium deficiency is easily managed through proper nutrition. Adding a high quality calcium source to a foliar nutritional program will help mitigate deficiencies. Because of its limited movement in the plant, adding calcium during critical development stages such as fruiting can vastly improve fruit quality, quantity and overall plant health. Calcium can also be added to soil fertility programs and applied in irrigation water to ensure adequate levels are spoon fed to the plant.
Monitoring soil calcium levels and sampling plant tissue can help you make good management decisions for proper calcium fertilization.