Rockdust
Encyclopedia
Rockdust, also known as rock powders, rock minerals, soil remineralization and mineral fines, is a non-synthetic organic fertilizer
usually consisting of crushed limestone but which may also be crushed basalt
(a volcanic rock
) containing minerals and trace elements, used in organic farming.
to improve fertility and has been tested since 1993 at the Sustainable Ecological Earth Regeneration Centre (SEER Centre) in Straloch, near Pitlochry
, in Perth and Kinross
, Scotland
. Further testing has been undertaken by James Cook University, Townsville, Far North Queensland
.
and drainage. Rockdust also provides calcium
, iron
, magnesium
, phosphorus
and potassium
, plus trace elements and micronutrient
s. By replacing these leach
ed minerals it is claimed that soil health is increased and that this produces healthier plants.
Typical composition table of rockdust
Available Silicon
Silicon
is thought to be the major element effecting the strength of cell wall development. However it is the amount of available silica that has a dramatic effect on the plant strength and subsequent health. To highlight this, plants that are grown in very sandy soils, (being high in non available silica), often require a silica based fertiliser to provide available silicon.
Silicon comes in silicon multi-oxide molecules (eg SiO2, SiO4, SiO6, SiO8 etc). Each molecule shape is thought to pack in different ways to allow different levels of availability.
Phosphate fixation
Often phosphorus is locked in soils due to many years of application of traditional fertilisers. The use of micronutrient rich fertiliser enables plants to access locked phosphorus.
Paramagnetism
The elements
high in available 2+ valence electrons, calcium, iron and magnesium in particular contribute to paramagnetism
in soil which aid in cation exchange capacity.
pH
The calcium
and magnesium
in high quality has the ability to neutralise pH
in soils, in effect acting as a liming agent
Spreading / applying dust in Agriculture
Rock Dust can be applied to soil either via hand application, via Broadcast spreader or fertigation
. Where possible the rockdust can be worked into the ground either physically or by using water to wash in.
Rate of Application
In some soils which display poor levels of nutrients, application rates of 10 tonnes per hectare are required. In Australia
, namely the Riverland
, Riverina
, Langhorne Creek, Barossa and Mclaren Vale
regions, rates are 3 - 5 tonnes per hectare. In a garden application, this might equate to 400 grams per square metre.
Rockdust is also the limestone-based product sprayed on walls inside underground coal mines to keep coal dust levels down. This is to prevent coal dust explosion
s and also to prevent the incidence of black lung disease. (Disambiguation is required here)
In the 20th century, rockdusting was popularized by science writers John D. Hamaker
, Larry Ephron, Alden Bryant, Don Weaver, Harvey Lisle, Arden Andersen and Dr. Lee Klinger.
Organic fertilizer
Organic fertilizers are naturally occurring fertilizers .Naturally occurring organic fertilizers include manure, slurry, worm castings, peat, seaweed, humic acid, and guano. Sewage sludge use in organic agricultural operations in the U.S...
usually consisting of crushed limestone but which may also be crushed basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
(a volcanic rock
Volcanic rock
Volcanic rock is a rock formed from magma erupted from a volcano. In other words, it is an igneous rock of volcanic origin...
) containing minerals and trace elements, used in organic farming.
Background
Rockdust is added to soilSoil
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...
to improve fertility and has been tested since 1993 at the Sustainable Ecological Earth Regeneration Centre (SEER Centre) in Straloch, near Pitlochry
Pitlochry
Pitlochry , is a burgh in the council area of Perth and Kinross, Scotland, lying on the River Tummel. Its population according to the 2001 census was 2,564....
, in Perth and Kinross
Perth and Kinross
Perth and Kinross is one of 32 council areas in Scotland, and a Lieutenancy Area. It borders onto the Aberdeenshire, Angus, Dundee City, Fife, Clackmannanshire, Stirling, Argyll and Bute and Highland council areas. Perth is the administrative centre...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
. Further testing has been undertaken by James Cook University, Townsville, Far North Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
.
Research
SEER's research claims that the benefits of adding Rockdust to soil include increased moisture-holding properties in the soil, improved cation exchange capacity and better soil structureSoil structure
Soil structure is determined by how individual soil granules clump or bind together and aggregate, and therefore, the arrangement of soil pores between them...
and drainage. Rockdust also provides 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...
, iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
, 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...
, 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...
, plus trace elements and micronutrient
Micronutrient
Micronutrients are nutrients required by humans and other living things throughout life in small quantities to orchestrate a whole range of physiological functions, but which the organism itself cannot produce. For people, they include dietary trace minerals in amounts generally less than 100...
s. By replacing these leach
Leach
Leach may refer to:Placenames* Leach, Oklahoma in the United StatesSurnames* Al Leach* Archie Leach, real name of actor Cary Grant* Ben Leach, player in Liverpool-based pop group The Farm* Bernard Leach , British potter* Bobby Leach...
ed minerals it is claimed that soil health is increased and that this produces healthier plants.
Typical composition table of rockdust
| Element | Unit | |
|---|---|---|
| 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... |
%w/w | 6.44 |
| iron Iron Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust... |
%w/w | 10.5 |
| 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... |
%w/w | 6.54 |
| sulphur | %w/w | 0.21 |
| 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... |
%w/w | 1.25 |
| 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... |
Mg/kg | 3030 |
| cobalt Cobalt Cobalt is a chemical element with symbol Co and atomic number 27. It is found naturally only in chemically combined form. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.... |
Mg/kg | 35 |
| copper Copper Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish... |
Mg/kg | 43 |
| manganese Manganese Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals... |
Mg/kg | 790 |
| Molybdenum Molybdenum Molybdenum , is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores... |
Mg/kg | <5 |
| zinc Zinc Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2... |
Mg/kg | 92 |
| silicon Silicon Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table... |
%w/w | 21.6 |
Available Silicon
Silicon
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
is thought to be the major element effecting the strength of cell wall development. However it is the amount of available silica that has a dramatic effect on the plant strength and subsequent health. To highlight this, plants that are grown in very sandy soils, (being high in non available silica), often require a silica based fertiliser to provide available silicon.
Silicon comes in silicon multi-oxide molecules (eg SiO2, SiO4, SiO6, SiO8 etc). Each molecule shape is thought to pack in different ways to allow different levels of availability.
Phosphate fixation
Often phosphorus is locked in soils due to many years of application of traditional fertilisers. The use of micronutrient rich fertiliser enables plants to access locked phosphorus.
Paramagnetism
The elements
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
high in available 2+ valence electrons, calcium, iron and magnesium in particular contribute to paramagnetism
Paramagnetism
Paramagnetism is a form of magnetism whereby the paramagnetic material is only attracted when in the presence of an externally applied magnetic field. In contrast with this, diamagnetic materials are repulsive when placed in a magnetic field...
in soil which aid in cation exchange capacity.
pH
The 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...
in high quality has the ability to neutralise 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...
in soils, in effect acting as a liming agent
Agricultural lime
Agricultural lime, also called aglime, agricultural limestone, garden lime or liming, is a soil additive made from pulverized limestone or chalk. The primary active component is calcium carbonate...
Spreading / applying dust in Agriculture
Rock Dust can be applied to soil either via hand application, via Broadcast spreader or fertigation
Fertigation
Fertigation is the application of fertilizers, soil amendments, or other water-soluble products through an irrigation system.Chemigation, a related and sometimes interchangeable term, is the application of chemicals through an irrigation system...
. Where possible the rockdust can be worked into the ground either physically or by using water to wash in.
Rate of Application
In some soils which display poor levels of nutrients, application rates of 10 tonnes per hectare are required. In Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, namely the Riverland
Riverland
The Riverland, is a region of South Australia. It covers the area near the Murray River from where it flows into South Australia downstream to Blanchetown.The major town centres are Renmark, Berri, Loxton, Waikerie and Barmera...
, Riverina
Riverina
The Riverina is an agricultural region of south-western New South Wales , Australia. The Riverina is distinguished from other Australian regions by the combination of flat plains, warm to hot climate and an ample supply of water for irrigation. This combination has allowed the Riverina to develop...
, Langhorne Creek, Barossa and Mclaren Vale
McLaren Vale
McLaren Vale is a wine region approximately 35 km south of Adelaide in South Australia. It has a population of about 2,000 and is internationally renowned for the wines it produces. The region was named after either David McLaren, the Colonial Manager of the South Australia Company or John...
regions, rates are 3 - 5 tonnes per hectare. In a garden application, this might equate to 400 grams per square metre.
Rockdust is also the limestone-based product sprayed on walls inside underground coal mines to keep coal dust levels down. This is to prevent coal dust explosion
Explosion
An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. An explosion creates a shock wave. If the shock wave is a supersonic detonation, then the source of the blast is called a "high explosive"...
s and also to prevent the incidence of black lung disease. (Disambiguation is required here)
History
Rockdusting, also known as soil remineralization was mentioned in the 19th century book Bread From Stones by chemist Julius Hensel.In the 20th century, rockdusting was popularized by science writers John D. Hamaker
John D. Hamaker
John D. Hamaker , was an American mechanical engineer, ecologist, agronomist and science writer in the fields of soil remineralization, rock dusting, mineral cycles, climate cycles and glaciology.-Biography:Background...
, Larry Ephron, Alden Bryant, Don Weaver, Harvey Lisle, Arden Andersen and Dr. Lee Klinger.
See also
- Organic farmingOrganic farmingOrganic farming is the form of agriculture that relies on techniques such as crop rotation, green manure, compost and biological pest control to maintain soil productivity and control pests on a farm...
- Rock flourRock flourRock flour, or glacial flour, consists of fine-grained, silt-sized particles of rock, generated by mechanical grinding of bedrock by glacial erosion or by artificial grinding to a similar size...
- Soil conditionerSoil conditionerA soil conditioner, also called a soil amendment, is a material added to soil to improve plant growth and health. A conditioner or a combination of conditioners corrects the soil's deficiencies in structure and-or nutrients.-Purpose:...
- Organic fertilizerOrganic fertilizerOrganic fertilizers are naturally occurring fertilizers .Naturally occurring organic fertilizers include manure, slurry, worm castings, peat, seaweed, humic acid, and guano. Sewage sludge use in organic agricultural operations in the U.S...
- John D. HamakerJohn D. HamakerJohn D. Hamaker , was an American mechanical engineer, ecologist, agronomist and science writer in the fields of soil remineralization, rock dusting, mineral cycles, climate cycles and glaciology.-Biography:Background...