soil nutrition - calcium

calcium plant and animal nutrition

plants use Ca in amounts second only to N and K. cell walls stiffness, cell elongation and division, membrane permeability. helps plant to protect against toxicities of other elements. major component of bones and teeth. redistribution mainly by transpiration (leaves>fruits). 

calcium healthy leaf tissue

0.1-5%

calcium environmental issues/implications

no serious off-site environmental problems. not toxic and does not cause eutrophication in aquatic systems. counteract soil and water acidification. influence on the species composition and productivity of terrestrial ecosystems

sources of calcium

organic matter, calcium-containing minerals (calcite, plagioclase), calcium on the clay and organic colloids

plants uptake calcium as

ion form (Ca2+)

calcium deficiency

very rare, except in acid soils. mainly in growing points (buds, unfolding leaves, fruits). new and low-transpiring tissue. shorter and denser root system.

Ca in soil fertility

easy to leach, usually the most abundant of the nonacid cations in soils (deficiencies are rare), lime is necessary in acid soils. 

Main sources of Ca

exchangeable Ca, Ca in readily weathered minerals (carbonates and apatite).

significant Losses of Ca

leaching, crop removal, soil erosion. roughly 1Mg/ha/year in humid-region agricultural soils