Calcium
/ˈkælsiəm/
Definition
Calcium is a mineral nutrient that plants take up as Ca2+, a positively charged ion. It becomes part of cell walls, helps build stable cell membranes, and supports normal growth in root tips, shoots, and other developing tissues. Because it moves poorly within most plants, deficiency symptoms usually appear first in new growth, unlike many mobile nutrients that plants can shift from older leaves.
Function in Plants
- Cell wall strength: calcium helps bind pectins in cell walls, giving tissues firmness and stability. This is especially important in young leaves, root tips, and developing fruits, where rapid growth depends on strong new cells.
- Limited movement inside plants: Once absorbed, calcium moves mainly with water in the xylem, the water-conducting tissue. Because it does not relocate easily from older leaves, deficiency symptoms usually appear first in new growth.
- Membranes and stress signaling: calcium supports cell membrane integrity and also acts as a signaling ion during stress and development. Short-term changes in cellular calcium levels help plants respond to drought, salinity, touch, and some pathogen attacks.
- Deficiency-linked disorders: Low calcium supply can lead to tissue collapse in fast-growing parts, including blossom end rot in tomato and pepper, tip burn in lettuce, and dieback of shoot tips. These problems often worsen when water supply is uneven.
Related Terms
Blossom end rot
Blossom end rot is a physiological disorder, not a disease, that affects developing fruits, especially tomato, pepper…
Fertilizer
Fertilizer is a substance added to soil, potting mix, or water to supply mineral nutrients that plants need for growth…
Micronutrients
Micronutrients are essential mineral elements that plants need in very small amounts for normal growth and metabolism…
Nitrogen
Nitrogen is a chemical element and essential plant nutrient, classified as a primary macronutrient because plants need…
Phosphorus
Phosphorus, in plant science, is an essential macronutrient and chemical element that plants take up mainly as…
Potassium
Potassium is an essential plant nutrient and chemical element that plants absorb as K+. Unlike nitrogen or phosphorus…
Soil
Soil is the natural surface layer of land where most plants root and grow. It is a living mixture of mineral particles…
Soil pH
Soil ph measures how acidic, neutral, or alkaline soil is, based on the concentration of hydrogen ions in the soil…