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Calcium

Calcium is Critical for Animal and Plant Health

Calcium is crucial for the cell strength.

Since calcium is the most immobile of all minerals and consequently, it is deficient in most plants. The most common reasons for calcium deficiency are excess of nitrogen, potassium, and magnesium that inhibit calcium intake.

Calcium deficiency may occur in soils with low base saturation or high acid content. In soils with insufficient Ca levels, the yield and quality of crops can be decreased, resulting in costly economic losses.

Deficiency symptoms first appear in the newly emerging leaves (see the picture) or developing tissues, while older leaves may contain sufficient concentrations of Ca.

Calcium deficiency affects the development of cell wall,1 and is characterized by necrosis of the tips of roots and young leaves or developing tissues (see the picture below).

Symptoms of Calcium deficiency

Functions of Calcium in plants

Key element in proteins
Cell wall development
Cell division and elongation
Nitrate uptake and metabolism
Enzyme activity
Starch metabolism

Calcium in soil

Calcium is the most dominant cation in the soil. Balancing soil calcium levels is the most essential element in any fertility program. Lack of calcium compacts the soil structure and limits the biological activity.

Optimal calcium levels feed microbes and improve the soil structure. Too much calcium may lead to too light soil and wind blow away. Most mineral soils in New Zealand contain between 0.1 and 5% calcium.

Severe weathering and leaching of soils may lead to deficiency in Ca. Calcium to magnesium ratio determines the soil structure and associates with gas exchange. The ideal base saturation is 68% of calcium, 12-15% magnesium, 3.5-5% potassium, 0.5-1.5% sodium.

Calcium to Magnesium ratio and the soil structure

Calcium is the fifth most abundant element in Earth’s crust and the third most abundant metal . Found in limestone and the fossilized remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium.

Calcium ions play a vital role in the physiological and biochemical processes of organisms and cells: in signal transduction pathways where they act as a second messenger; in neurotransmitter release from neurons; in contraction of all muscle cell types; as co-factors in many enzymes; and in fertilization.

Calcium ions outside cells are important for maintaining the potential difference across excitable cell membranes, protein synthesis, and bone formation.

How does calcium influence the soil structure?

Calcium is a positively charged ion called a cation. Cations are absorbed by the plant roots and also held on exchange sites in soils. The positive charges of calcium are attracted to negative electrical charges found on the exchange sites on clay particles and Organic Matter (OM). The more clay and OM, the larger the attraction.

Calcium tends to flocculate and help from stable aggregates, resulting to good spore space for water, roots and microbes.
Soil aggregates refers to flocculated clusters of sand, silt and clay particle. Clay particles have negative electrical charge, negatively charged clay particles repel each other. Cations make clay particles to flocculate (stick together).

In soil with a good structure, the particles of sand and silt are held together in aggregates (small clumps) by clay, humus and calcium. The large empty spaces between the aggregates (macropores) allow water and air to circulate and plant roots to grow down into the soil. The small empty spaces (micropores) hold the water the plants need.

How to Improve Calcium Uptake

Beneficial fungi are one of the key players in the uptake of calcium. Fulvic acid combined with calcium nitrate creates a calcium fulvate – one of the most inexpensive, yet effective calcium delivery tools.

Calcium inputs

  • High calcium limestone.
  • Foliar organic chelates.
  • Gypsum.
  • Attach with carbon – compost, humaters, carbs etc.
  • Apply in small quantities.