DayCent is a

biogeochemical Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment (including the biosphere, the cryosphere, ...

model A model is an informative representation of an object, person, or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin , . Models can be divided in ...

agroecosystems Agroecosystems are the ecosystems supporting the food production systems in farms and gardens. As the name implies, at the core of an agroecosystem lies the human activity of agriculture. As such they are the basic unit of study in Agroecology, and ...

, simulating fluxes of

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

and

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

between the

atmosphere An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

vegetation Vegetation is an assemblage of plants and the ground cover they provide. It is a general term, without specific reference to particular Taxon, taxa, life forms, structure, Spatial ecology, spatial extent, or any other specific Botany, botanic ...

, and

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

. It is a daily time series version of the CENTURY biogeochemical model. The

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent agency of the United States government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it began operation on De ...

United States Department of Agriculture The United States Department of Agriculture (USDA) is an executive department of the United States federal government that aims to meet the needs of commercial farming and livestock food production, promotes agricultural trade and producti ...

/ARS and the

Colorado State University Colorado State University (Colorado State or CSU) is a Public university, public Land-grant university, land-grant research university in Fort Collins, Colorado, United States. It is the flagship university of the Colorado State University Syst ...

Natural Resource Ecology Lab are currently using the DayCent model to develop a national

inventory Inventory (British English) or stock (American English) is a quantity of the goods and materials that a business holds for the ultimate goal of resale, production or utilisation. Inventory management is a discipline primarily about specifying ...

of N₂O emissions from

U.S. The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

agricultural soils. This inventory will be compared and contrasted with the existing

Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to "provide governments at all levels with scientific information that they can use to develop climate policies". The World Met ...

(IPCC) agricultural N₂O emissions inventory for the United States. Having more accurate data to account for

nutrient cycling A nutrient cycle (or ecological recycling) is the movement and exchange of inorganic and organic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cyc ...

could have significant implications for public policy associated with the

United Nations Framework Convention on Climate Change The United Nations Framework Convention on Climate Change (UNFCCC) is the UN process for negotiating an agreement to limit dangerous climate change. It is an international treaty among countries to combat "dangerous human interference with th ...

(UNFCCC) and potential future

mitigation Mitigation is the reduction of something harmful that has occurred or the reduction of its harmful effects. It may refer to measures taken to reduce the harmful effects of hazards that remain ''in potentia'', or to manage harmful incidents that ...

efforts in the United States. Model inputs include daily minimum and maximum air

temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...

and

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

, surface

soil texture Soil texture is a soil classification, classification instrument used both in the field and laboratory to determine soil classes based on their physical texture. Soil texture can be determined using qualitative methods such as texture by feel, and ...

class, and

land cover Land cover is the physical material at the land surface of Earth. Land covers include flora, concrete, built structures, bare ground, and temporary water. Earth cover is the expression used by ecologist Frederick Edward Clements that has as ...

use Use may refer to: * Use (law), an obligation on a person to whom property has been conveyed * Use (liturgy), subset of a Christian liturgical ritual family used by a particular group or diocese * Use–mention distinction, the distinction between ...

data. Model outputs include daily fluxes of various N-gas species (e.g., N₂O, NO_x, N₂); daily CO₂ flux from heterotrophic soil respiration; soil organic C and N;

net primary productivity In ecology, primary production is the synthesis of organic compounds from atmospheric or aqueous carbon dioxide. It principally occurs through the process of photosynthesis, which uses light as its source of energy, but it also occurs through ...

; daily water and

nitrate Nitrate is a polyatomic ion with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in wa ...

(NO₃) leaching, and other

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

parameters. DayCent has been tested using data from various native and managed systems. In similar studies, comparisons between DayCent simulated data and measured values for annual crop yields, N₂O emissions, and NO₃ leaching produced r² values of 0.72, 0.68, and 0.61 respectively.Del Grosso, Stephen, "Daycent Model Estimates of Greenhouse Gas Mitigation Potential of Cropped Soils in the USA." Session No. 70 U.S. Agriculture’s Role in Soil Carbon Sequestration and Greenhouse Gas Mitigation (GRACEnet) George R. Brown Convention Center: General Assembly Theater Hall C 1:30 PM-5:30 PM, Tuesday, 7 October 2008

References

External links

* {{DEFAULTSORT:Daycent Agronomy Agriculture and the environment Systems ecology