The intent here is to have a collection of terms in one place that is easily available. This list may grow and change over time.
Disclaimer: There are many good and varied definitions for the same terms. This selection is one group of them. If you have a definition that you think is a good addition or a better option to be considered, please send it to suggestions@soilcarbonwatch.org

Commonly Used Terms

​Soil is a mixture of minerals, organic matter, gases, liquids, and countless organisms that together support life on Earth. Soil is a natural body called the pedosphere which has four important functions: it is a medium for plant growth; it is a means of water storage, supply and purification; it is a modifier of Earth's atmosphere; it is a habitat for organisms; all of which, in turn, modify the soil. (Wikipedia.org, Soil)
 
Dirt is unclean matter, especially when in contact with a person's clothes, skin or possessions when they are said to become dirty. (Wikipedia.org, Dirt)

​Carbon Sequestration is the process involved in carbon capture and the long-term storage of atmospheric carbon, such as carbon dioxide (CO2). Carbon dioxide is naturally captured from the atmosphere through biological, chemical, and physical processes. (Wikipedia.org, Carbon Sequestration)
 
Climate Change Mitigation consists of actions taken to limit the overall magnitude of climate change or to limit the rate of changes occurring because of climate change. It also serves to improve our resilience to its impacts.

Terms for Different Farming and Agriculture Perspectives

Agriculture is the cultivation of animals, plants and fungi for food, fiber, biofuel, medicinal plants and other products used to sustain and enhance human life. (Wikipedia.org, Agriculture)

Regenerative Agriculture is the practice of farming designed to build soil health and regenerate unhealthy soils. (Wikipedia.org, Regenerative Agriculture)

Sustainable Agriculture is the practice of farming that does not degrade the system. In the U.S. following the time of the dust bowl, the focus of sustainable agriculture was to protect against erosion.
 
Organic Agriculture is an alternate agriculture system to conventional agriculture. It relies on fertilizers derived from organic materials. It prohibits the use of synthetic fertilizers and pesticides. Food grown using organic methods is legally defined in the U.S. and internationally. It does not necessarily use regenerative agricultural practices.
 
Conventional Agriculture is the term used to refer to agricultural practices developed in the mid and late 20th century. It uses synthetic fertilizers, pesticides and herbicides. It tends to be large scale and monoculture. It is highly mechanized.
 
Climate Smart Agriculture is the practice of farming that reduces carbon emissions, sequesters carbon and balances the water cycle.

Carbon Farming is used to describe a suite of crops and agricultural practices that sequester carbon in the soil. (The Carbon Farming Solution, Eric Toensmeier)
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Permaculture is a system of agricultural and design principles centered on simulating or directly utilizing the patterns and features observed in natural ecosystems. (Wikipedia.org, Permaculture)

Ecological Farming uses methods to regenerate ecosystem services like: prevention of soil erosion, water infiltration and retention, carbon sequestration in the form of humus, and increased biodiversity. (Wikipedia.org, Ecological Farming)

Agroforestry (also known as agro-sylviculture) is a land use management system in which trees or shrubs are grown around or among crops or pastureland. (Wikipedia.org, Agroforestry)

Agroecology is the study of ecological processes that operate in agricultural production systems. (Wikipedia.org, Agroecology)
 
Restorative Ecology is the study and practice of the restoration of ecological systems.
 
Ecosystem Services are benefits that derive from functional ecosystems.

Terms for Farming Practices that Encourage Healthy Soil

No-Till refers to the practice of not tilling (ploughing, plowing) the crops.
 
Compost is organic matter that is used as fertilizer and soil amendment.
 
Mulch is a layer of organic material added to the soil surface to reduce weeds, hold moisture, and protect the soil from temperature changes and erosion.

Cover Crops are planted following or along side a crop to protect and regenerate the soil. It may also be an additional productive yield.
 
Managed Intensive Rotational Grazing (MIRG), Rotational Grazing, Wholistic Land Management, Holistic Planned Grazing, Cell Grazing, Mob Grazing and Managed Grazing all refer to systems of forage use in which ruminant and non-ruminant herds and/or flocks are regularly and systematically moved to fresh rested areas with the intent to maximize the quality and quantity of forage growth. (Wikipedia.org, Rotational Grazing)

Terms for Soil Composition

Organic Matter (OM) is made of carbon-based chemical compounds derived from plants and animals. 
 
Soil Organic Carbon (SOC) is a general term for organic matter. It includes carbon in living biota and dead biotic material comprising the soil food web. It includes humus, a more inert form of carbon.
 
Soil Carbon (SC) includes both inorganic carbon as carbonate minerals and organic carbon as organic matter.

Humus is organic matter that has been acted upon by microorganisms. It holds nutrients. It’s amorphous, often in the form of hydrocarbon chains and loops. It can persist in the soil for long periods.

Biomass is organic material.

Terms for Soil Tests

Organic Matter - Loss On Ignition (OM-LOI) is a common soil test for organic matter done in the lab. Organic Matter is measured through loss on ignition by burning it. It’s reported as a percentage of OM in the soil.
 
OM measured with hydrogen peroxide is a soil test for organic matter. The sample reacts with hydrogen peroxide and bubbles off CO2. Often used in the field.
 
Total Organic Carbon (TOC) is a soil test that measures total organic carbon in all forms of the soil. It is multistep and uses higher temperature combustion. It’s best used with low inorganic carbon soils, so not to dissolve the minerals.
 
Total Carbon (TC) is a soil test that measures all organic and inorganic carbon (including minerals) in the soil using higher temperatures. Total elemental analysis is often used for research, but is not necessary for deciding fertilizer application.