aka Surface horizon

The horizon thathas had something eluviate from it. May have an accumulation of organic matter.

The zone in a glacier where ice originates from. In Canada there was one in BC, NWT, and in northern Quebec.

A surface horizon with light colour. Lacks organic matter. Has clay, orion, aluminum, and/or carbon.

Clump of soil.

A surface horizon with dark colour, enriched in organic humic matter. H is for humic.

Increased phosphorus in the water from manure or fertilizer run-off causes algae to overpopulate. When they die and are eaten by other bacteria, all the oxygen in the water is used up and larger oxygen-breathing life-forms like fish and crustaceans suffocate. Algae are not rooted to the ground, they float freely in the water.

The third most common element in the earth's crust. A mineral with high mobility in the soil when pH is low. A B horizon that has had aluminum illuviate into it is Bf.

A surface horizon similar to Ah but cultivted. P is for plowed. This horizon will have a perfectly uniform depth because of tillage. In the tillage zone all the layers are mixed.

A mountain glacier in BC. It is receding.

aka Subsurface horizon.

The horizon under A. Something has illuviated into it out of the A horizon.

Ah, Bm, Ck

A soil order in Canada. Has a Bm horizon. Has a thin Ah. Minimally developed B horizon. Develops out of regosol. With time it develops into luvisol. Found in forested areas.

The mass of soil solids divided by the total volume of the soil (including pores).

Higher BD results in shorter, thicker roots.

Cultivation increases buld density over time.

CaCO₃

Aka Lime

A type of limestone. Used to raise the pH of soils. When it dissolves, it turns into Ca⁺², HCO₃, and OH^-. Ca⁺² takes up two exchance sites rather than one. It reacts with H⁺ and OH^- form water and H₂CO₃ or CO₃. How well it raises pH depends on how finely ground it is, its purity, and the CEC of the soil. Adding to the top 15 cm of the horizon and moves downwards 2 cm - 3 cm/year. The impact of liming lasts only for a while, then the pH goes down again. How fast it decreases depends on CEC. No matter what the CEC, the same amount of lime is needed to maintain a high pH; lower CEC soils need more frequent liming with less calcite.

Similar to the classification of organisms. Nested groups:

Order > Great Groups > Subgroups > Families > Series

Cation Exchange Capacity

A measure of the soil's ability to hold onto cations.

70 million years  ago - present

The most recent geologicl period. Includes the Recent period, Pleistocene period, and Tertiary period. Mammoths, sabre-tooth tigers, and early humans existed during this period.

Ah, Bm, Ck

A soil order in Canada. The term is Russian in origin. Has a deep Ah horion high in organic matter. Has a Bm horion, but is not classified as brunisol due to the overriding Ah horizon. Found in the southern grassland praries. The perennial grass is what gives the soil such high organic matter. from the south moving northwards there is brown, dark brown, black, and then dark grey chernozems, then luvisols.

Particles under 0.002 mm in size. A primary particle. Part of the basis for soil texture. A region of the textural triangle. Has a sticky consistency when wet, and is hard when dry. Feels smooth when rubbed betwen fingers. Moderate to strong shine. Forms very strong caste. Forms a ribonn greater than 5 cm long. Particles are flat like tiny sheets of paper. Generally negatively charged. Soils high in clay tend to have columnar structure. 

90 billion particles and 8 million cm³ of surface area per gram of clay.

Bulk density of 1.05 M/m³ and a pore space ratio of 60%.

Has a resistance of 700 - 770 g/m³ against plowing

A region of the textural triangle. Feels smooth and floury. Has a slight shine. Forms a strong caste. Forms a ribbon 2.5 cm - 5 cm long.

Has a bulk density of 1.1 Mg/m³ and a pore space ratio of 59%.

When moist it has a resistance of 420 - 490 g/cm³ against plowing.

Sand with a particle size 1 mm to 0.5 mm.

750 particles and 23 cm³ of surface area per gram of coarse sand.

A form of soil degradation. Caused by traffic over soil. Not to be confused with shear. Bulk density increases and there is a loss in larger pores. Aggregates are re-arranged.

Compaction can be reduced by decreasing axle load, reducing tire pressure, radial tires, increased tire size, traffic only over dry soil, and reduced traffic.

aka Permafrost

A soil order in Canada. Has a Y horizon. Frozen soils. By area, the most common soil type in Canada. Found in the northern regions of Canada.

CaMg(CO₃)₂

A type of limestone. An alternative to using calcite. Same chemical effect, except that dolomite has two carbonates rather than one, giving it a greater capacity to change pH. Dolomite is cheaper than calcite.

A glaciofluvial formation formed when rivers form underneath a glacier between the ice and bedrock. The ice erodes away, and gravel falls to the floor of the bedrock. When the glacier recedes, it leaves a positive mound of gravel.

Eskers are uncommon on the landscape because people harvest them for sand and gravel.

Sand with particle size 0.25 mm - 0.1 mm. 

46,000 particles and 91 cm³ surface area per gram of soil.

 A horizon suffix used to describe evidence of reduced conditions. G is for gleyed. No oxygen results in the reduced blue-grey coloured form of iron.

Found in B and C horizons. Can be in an A horizon, but organic matter would overshaddow the blue-gey colour.

Ap, Bg, Ckg

A soil order in Canada. Soil that is wet for most of the year. Iron is reduced in the low-oxygen conditions, and gives the soil a blue-grey colour. May have pockets of oxidized red iron due to air pores. Found in the middle zone of topographical features. Moving up the slope, it turns into gleyed podzol and then podzol.

A 1:1 clay structure. One silica tetrahedron sheet is bonded to an octahedron sheet. One sheet has no charge, but is polar; the octahedral side is more positive. Hydrogen bonding then forms between these bonded sheets due to the polarity. Low shrink-swell potential.

CEC is 2 - 6 cmole/kg.

Surface area is 8 - 16 m²/g.

Forest Humus Layer

An organic horion. Can be at various stages of decomposition. A usually thin layer of pine needles and leaves.

A region of the textural triangle. When gardeners use this term, they are referring to something else.

Has a bulk density of 1.2 Mg/m³ and a pore space ratio of 55%. Feels sticky, with evidence of graininess. Forms a weak to moderate caste. Forms a ribbon less than 2.5 cm long.

Ap, Ae, Bt, Ck

A soil order in Canada. Has a Bt horizon. Clay has illuviated into the B horizon. Exists on calcareous parent material. Includes grey-brown luvisol and grey luvisol. Found in BC, the north prairies, Ontario, and in the Maritimes. Develops out of brunisol. Deciduous trees flourish in this soil.

220 million years ago - 135 million years

Includes the Cretaceous, Jurassic, and Triassic periods.

aka Muck

A soil order in Canada. Not to be confused with the agricultural management technique.

Has a different classification system than mineral soils, which is based on the decomposition stage. Found in pockets in the prairies and Ontario where it is wet all year around, such as the Holland marsh. Found in the lower areas of topographical features, forests, swamps, and diked-off areas. The water slows decomposition, causing a build-up of organic matter.

550 million years ago - 275 million years ago

Includes the Permian, Pennsylvanian, Mississippian, Devonian, Silurian, Ordovician, and Cambrian periods. Dinosaurs existing during this period.

aka Bedrock

A geological process soil formation factor. Effected by weathering and glaciers (and glacial meltwater). Bedrock determines chemical composition of soils, and glacial activity determines soil texture.

pH = -log[H⁺]

The acidity of soil. A high number means basic. A low number measn acidic. Measured with a pH electrode or coloured dyes such as bromothymol blue. There is an equilibrium between the H+ on exchange sites and in the soil solution. CEC, calcium carbonate, and sodium carbonate can act as buffers. Depends on the mineralogy, carbonate levels, and management. In southern Ontario soils are basic. As you go north it gets more acidic. Pines and spruces prefer acidic soil. You can raise the pH of soil by liming it.

LFH, Ae, Bf, Ck

A soil order in Canada. Exists on igneous based parent material. Has a Bf horizon. Iron illuviated into the B horizon, making it red in colour. Has a low pH. May leave silicon in the A horizon bare, making bright white coloured pockets. Found on the Canadian Shield where there are forests. Found at the top of topographical features, moving down the slope it becomes gleyed podzol then gleysol.

Ah, Ck

A soil order in Canada. Young, relatively uneveloped soil. Lacks a B horizon. With time it turns into brunisol. Found mainly in NWT and the Yukon near the Mackenzie River, but also in areas that are frozen most of the year, or have been recently disturbed for example by human activity or a natural disaster.

Rock particles 0.002 mm to 0.05 mm in size. A primary particle. Part of the basis for soil texture. Feels smooth and powdery like flour. Particles are too small to see. Not plastic or sticky when moist. A region of the textural triangle. The particle most susceptible to erosion. It takes 8 hours to drop 10 cm through still water.

5,776,000 particles and 454 cm³ surfacea rea per gram of silt.

A 2:1 clay structure. A silica tetrahedron sheet bonds to both sides of an octahedron sheet. Ions attach to the sides of the silica tetrahedron sheets, pushing individual sheets apart. High shrink-swell potential.

CEC is 60 - 100 cmole/kg.

Surface area is 750 - 820 m²/g.

aka not Dirt

A naturally occuring mineral and/or organic material at least 10 cm deep. Not only part of the environment; a product of the environmnent. A productive resource. Soils have been forming for as long as the land has existed. It is effected by as well as formed out of orgnaisms that live and on it. Formed by climate, geological factors, life, and time.

Ah, Ahe, Bnt, Csk

A soil order in Canada. Has a Bnt horizon. Has a build-up of sodium salts. Found in pockets in the prairies. High pH. Toxic to plants. The salt can osmotically drain water out of plants. The salt pushes clay sheets aprt, breaking up aggregates and giving the soil bad pysical properties for growing plants. When it is dry, evapotranspiration draws salt to the surface; the effect appears like a blanket of snow. When it is wet, the salt is washed down to the lower horizons.

Used to determine texture from the hydrometer or pipette method.

t = h / (Kr²)

K = 347,000/cm*s

A soil physical property. The arrangement of individual soil aggregates into structures. Parent material is separated into secondary units. Single grain, granular blocky, columnar, platy, and massive. More stable strcuture do not erode as easily. Structure is developed by dring, freezing, thawing, and biological activities.

Characteristics: particle density, bulk density, volume fractrion of pores, and pore size, distribution, and continuity.

Determined by organic matter, water, trafifc, and tillage. Structure effects water movement, aeration, root penetration, ease of cultivation, and erosion. 

Controlled by management: improved with reduced tillage, crop residue, crop rotation, manure, adding organic matter, and reducing compaction.

 Loss of structure is a form of soil degradation.

A pedological process soil formation factor. Effects drainage, seasonal average soil water content, erosion, and translocation.

Higher soils are dryer, have less organisms, less organic matter, and are subject to erosion. They have a thinner A horizon.

Lower soil are wetter, have more organic matter, and have a thick A horizon.

A factor in water erosion and in the USLE equation. Determined based on slope angle (S), and length of slope (L). Erosion can be decreased by building terraces.

NH₃

Used as a cleaner. It kills all respiring cells, including plant cells. During nitrogen conversion, there is risk of ammonia toxicity. It can be tured into urea by adding CO₂, turned into nitric acid by adding O₂, and turned into ammonium nitrate by adding nitric acid.

NH₄⁺

A cation. Has a large molecular radius. Attaches to CEC sites, so it is stable in the soil. A form of N that plants can uptake. Once taken up, N is organic matter.

NH₄NO₃

34-0-0

A nitrogen fertilizer. Made by mixing ammonia and nitric acid. A component of UAN. Can be used for making explosives.

NH₂

82-0-0

A nitrogen fertilizer. If applied incorrectly, can lead to ammonia volatilization,

N₂

78% of the atmosphere is nitrogen. It takes a large amount of energy to break the triple bond between the two nitrogen atoms. No plant can do this. Some bacteria can fix it into a form that plants can uptake, including rhizobium bacteria. It can be turned into ammonia via the Haber process.

aka Cyanobacteria

Autotrophic algae. Contain chlorophyll and are capable of fixing N from the atmosphere. Cause eutrophication. Fix nitrogen at a rate of 25 kg/ha.

The ratio between C and N atoms in organic matter. It determines if the nitrogen will mineralize or immobilize during decomposition.

Less than 30:1 and it will mineralize.

More than 30:1 and it will immobilize.

The C:N ratio of soil microbes is 8:1. Respiration accounts for 70% of the carbon being lost.

Without conservation, a flow resource will provide a lot at first but over time decrease.

With conservation, a flow resrouce will provide the same level for all time.

Includes soil, water, and air conservation. Family-owned lands are more likely to practice conservation than rented lands.

A nitrogen loss. Nitrate is converted into N₂O or N₂ by heterotrophic bacteria, often in anaerobic conditions. Rate of denitrification depends on oxygen level (faster when oxygen is limiting), levels of nitrates and organic nitrogen, temperature, and pH. It can lead to excessive nitrous oxide emissions.

NO₃ -> NO₂ -> NO -> N₂O -> N₂

There are 100 - 1700 kg of earthworms per hectare. Their burrowing improves porosity, aeration, and water flow. They mix organic matter. The slime they secrete stabilizes soil structures. Sometimes they are harvested for use as fish bait.

Earthworms are not native to Ontario, they were brought from Europe in potted plants. They cannot migrate quickly. 

A factor in soil water erosion. Texture, structure, and organic matter of soil. It is factor K in the USLE equation. Determined from a textural triangle or a table of textural classes.

The B and C horizons are more erodable, so when erosionr reaches the B horizon the rate of erosion speeds up.

The percentage by weight of nitrogen, phosphorus, and potassium respectively

N-P-K

aka Renewable resource

A resource that is not depleted when used, provided that the rate of consumption is no greater than the rate of regeneration. Has a carrying capacity.

The bucket has a number of holes in it and a tap is filling the bucket at a certain rate. The water level in the bucket always reaches an equilibrium that depends on the rate of the tap and the size, number, and height of the holes.

Organic matter levels in the soil reach equilibrium like this. The tap represents organic matter input, and the holes represent organic matter removal and decomposition.

The sum of gravitational potential, matric potential and pressure potential.

Ψ_h = Ψ_g + Ψ_m + Ψ_p

aka The water cycle

Includes runoff, infiltration, percolation, evaporation, transpiration, and precipitation.

A 2:1 clay structure. A silica tetrahedron sheet bonds to both sides of an octahedron sheet. Has no charge. The sheets are then held together with potassium ions. These ions are stuck in the structure. Low shrink-swell potentiall. Over time in the soil, the interlayer spaces are weathered apart, turning into smectite or vermiculite.

CEC is 20 - 40 cmol/ha.

Surface area is 100 - 200 m²/g.

aka Quick clays

Clays high in sodium. Very susceptible to erosion when wet. They dissolve in water. They were the cause of the landslide in La Baie, Quebec.

A nutrient needed in large quantities.

Includes C, H, O, N, P, and K. And the secondary nutrients, Ca, Mg, and S.

aka Blue baby syndrome.

A disease caused by high nitrogen in water caused by leaching.

aka Mobilization

The main source of inorgnic N in the soil. Decomposition of organic matter by heterotrophic organisms. Creates NH₄, CO₂, H₂O, and other plant nutrients. Nitrogen in excess of the organism's needs is excreted in these forms. OM must have a C:N ratio less than 30:1. Organic phosphorus is turned into H2PO₄^-, HPO₄^-2, and PO₄^-3.

10-10-10

A phosphorus fertilizer made by mixing sulfuric acid, rock, phosphate, ammonia, and heat. Costs $0.34/kg. Can lead to overapplication problems.

11-52-0

A phosphorus feritlizer made by mixing rock phosphate, sulfuric acid, ammonia, and heat. Costs $0.70/kg. The safest fertilizer in terms of safety and seed injury.

KCl

aka Potassium chloride

0-0-60

Costs $0.58/kg. The purified form of potash ore. The form of potassium in most ferilizers. Can be processed into potassium sulphate and potassium nitrate.

NO₃^-

An anion. Has a small molecular radius. Cannot attach to exchange sites; instead it stays in the soil solution. Very susceptible to leaching. A form of nitrogen available to plants.

HNO₃

Made by combining ammonia and O₂ at high temperatures. Corrodes equipment.

An autotrphic bacteria that performs the second step in nitrification.

NO₂^- + ½ O₂ -> NO₃^- + Energy

An autotrophic bacteria that performs the first step in nitrification.

NH₄⁺ + O₂ -> NO₂^- + H⁺ + Energy

N₂O

A greenhouse gas. It is released during denitrification. 50% - 80% of the increase in nitrous oxide emissions are due to agriculture.

aka Ground water outflow

Water running away underground. Part of the equation for water budget.

Found in a huge area 1 km underground in Saskatchewan. Contains sand, clay, potassium chloride, and sodium chloride. It is purified into muriate of potash. Sand is removed with wter. Sodium chloride is removed by heating and removing the crystals.