Agricultural lime

Agricultural lime

Discussion
Ask a question about 'Agricultural lime'
Start a new discussion about 'Agricultural lime'
Answer questions from other users
Full Discussion Forum
 
Encyclopedia
Agricultural lime, also called aglime, agricultural limestone, garden lime or liming, is a soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 additive made from pulverized limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 or chalk
Chalk
Chalk is a soft, white, porous sedimentary rock, a form of limestone composed of the mineral calcite. Calcite is calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite plates shed from micro-organisms called coccolithophores....

. The primary active component is calcium carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...

. Additional chemicals vary depending on the mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

 source and may include calcium oxide
Calcium oxide
Calcium oxide , commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline crystalline solid at room temperature....

, magnesium oxide
Magnesium oxide
Magnesium oxide , or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium . It has an empirical formula of and consists of a lattice of Mg2+ ions and O2– ions held together by ionic bonds...

 and magnesium carbonate
Magnesium carbonate
Magnesium carbonate, MgCO3, is a white solid that occurs in nature as a mineral. Several hydrated and basic forms of magnesium carbonate also exist as minerals...

.

Effects on soil:
  • it increases the pH
    PH
    In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

     of acid
    Acid
    An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

    ic soil
    Soil
    Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

     (the higher the pH the less acidic the soil)
  • it provides a source of calcium
    Calcium
    Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

     and magnesium
    Magnesium
    Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

     for plants
  • it permits improved water penetration for acidic soils
  • it improves the uptake of major plant nutrients(Nitrogen
    Nitrogen
    Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

    , Phosphorus
    Phosphorus
    Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...

    , and Potassium
    Potassium
    Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...

    ) of plants growing on acid soils.


Lime
Lime (mineral)
Lime is a general term for calcium-containing inorganic materials, in which carbonates, oxides and hydroxides predominate. Strictly speaking, lime is calcium oxide or calcium hydroxide. It is also the name for a single mineral of the CaO composition, occurring very rarely...

 may occur naturally in some soils but may require addition of sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...

 for its agricultural benefits to be realized. Gypsum
Gypsum
Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...

 is also used to supply calcium for plant nutrition. The concept of "corrected lime potential" to define the degree of base saturation in soils became the basis for procedures now used in soil testing laboratories to determine the "lime requirement" of soils.

Other forms of lime have common applications in agriculture and gardening, including dolomitic lime and hydrated lime. Dolomitic lime may be used as a soil input to provide similar effects as agricultural lime, while supplying magnesium in addition to calcium. In livestock farming, hydrated lime can be used as a disinfectant measure, producing a dry and alkaline environment in which bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 do not readily multiply. In horticultural farming it can be used as an insect repellent, without causing harm to the pest or plant.

Spinner-style lime spreaders are generally used to spread agricultural lime on fields. Several companies such as Stoltzfus Spreaders manufacture spreaders for this purpose.

Agricultural lime is injected into coal burners at power plants to reduce the NOX and SO from the emissions.

Determining the Need for Agricultural Lime (Aglime):
The primary reason to apply Agricultural Lime is to correct the high levels of acidity in the soil. Acid soils reduce plant growth by inhibiting the intake of major plant nutrients (Nitrogen, Phosphorus and Potassium). Some plants, particularly legumes, will not grow in highly acidic soils.

Soils become acidic in a number of ways. Locations that have high rainfall levels become acidic through leaching. Land used for crop and livestock purposes lose minerals over time by crop removal and become acidic. For example when a 600 lb. calf is removed from a pasture, 100 lbs. of bone is also removed, which is 60 % calcium compounds. The application of modem chemical fertilizers is a major contributor to soil acid by the process in which the plant nutrients react in the soil.

Aglime, which is high in calcium, can also be beneficial to soils where the land is used for breeding and raising foraging animals. Bone growth is key to a young animal’s development and bones are composed primarily of calcium and phosphorus. Young mammals get their needed calcium through milk, which has calcium as one of its major components. Dairymen frequently apply aglime because it increases milk production.

The best way to determine if a soil is acid or deficient in calcium or magnesium is with a soil test. A soil test can normally be provided by a University with an Agricultural Education Department for under $30.00. Farmers typically become interested in soil testing when they notice a decrease in crop response to applied fertilizer.

Agricultural Lime Quality:

The quality of Agricultural limestone is determined by the chemical makeup of the limestone and how finely the stone is ground. To aid the farmer in determining the relative value of competiting agricultural liming materials, the Agricultural Extension Services of several universities use two rating systems. Calcium Carbonate Equivalent (CCE) and the Effective Calcium Carbonate Equivalent (ECCE) give a numeric value to the effectiveness of different liming materials.

The CCE compares the chemistry of a particular quarry’s stone with the neutralizing power of pure Calcium Carbonate. Because each molecule of Magnesium Carbonate
Magnesium carbonate
Magnesium carbonate, MgCO3, is a white solid that occurs in nature as a mineral. Several hydrated and basic forms of magnesium carbonate also exist as minerals...

 is lighter than Calcium Carbonate
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...

, limestones containing Magnesium Carbonate (Dolomite
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....

) can have a CCE greater than 100 percent.

Because the acids in soils are relatively weak, agricultural limestones must be ground to a small particle size to be effective. The Extension Service of different states rate the effectiveness of stone size particles slightly differently. They all agree, however, that the smaller the particle size the more effective the stone is at reacting in the soil. Measuring the size of particles is based on the size of a mesh that the limestone would pass through. The mesh size is the number of wires per inch. Stone retained on an 8 mesh will be about the size of BB pellets. Material passing a 60 mesh screen will have the appearance of face powder. Particles larger than 8 mesh are of little or no value, particles between 8 mesh and 60 mesh are somewhat effective and particles smaller than 60 mesh are 100 percent effective.

By combining the chemistry of a particular product (CCE) and its particle size the Effective Calcium Carbonate Equivalent (ECCE) is determined. The ECCE is percentage comparison of a particular agricultural limestone with pure calcium carbonate with all particles smaller than 60 mesh. Typically the aglime materials in commercial use will have ECCE ranging from 45 percent to 110 percent.

External links

Transcription of 1919 text by Alva Agee.