Football

Calcium is the structural component of the middle layer of the plant cell wall, where it serves as a cementing agent as calcium pectate. It is responsible for preventing damage to the cell membrane, preventing the escape of intracellular substances and, therefore, maintaining its integrity.

Calcium acts as a second messenger in the function of some hormones and in environmental responses. On the one hand, it acts as an enzymatic modulator of plant hormones, regulating germination, growth, and senescence. On the other hand, small variations in Ca2+ concentration can trigger adaptation and environmental response mechanisms to changes in pH, light, temperature, and other factors that may occur in the environment.

Furthermore, calcium is essential for the regeneration of saline-sodium soils, producing clay flocculation by exchanging sodium ions for calcium, which improves the structure and quality of agricultural soil.

ABSORPTION

The natural form of calcium absorption is through the roots in the form of Ca+2, and it can also be absorbed by the leaves.
Calcium is abundant in most soils, although it is limiting in acidic soils with abundant rainfall, where the contribution of carbonates is necessary to raise the pH.

DEFICIENCIES

Calcium is not a mobile element, so the plant depends on the transpiration process for its roots to absorb it from the soil solution. Any factor that alters the rate of transpiration, such as high humidity or extreme temperatures, can cause calcium deficiency even if the soil has a normal calcium level.

An increase in soil salinity could also cause Ca+2 deficiency by decreasing water absorption by the plant.

The first symptoms of calcium deficiency appear in plant parts that transpire little water, namely young leaves and fruits. The leaves appear chlorotic, rolled, and curled. Root development is also delayed, and fruit exhibits problems such as creasing in citrus fruits, splitting in citrus and fruit trees, and blossom end rot in tomatoes. Calcium deficiency also inhibits pollen germination and pollen tube growth.