Acre (ac) a unit of area traditionally defined as the area of one chain (66 feet) by one furlong (660 feet), equivalent to 43,560 square feet 001563 sq mi; 4,047 m2), or about 40 hectare acre-foot

acre (ac)
A unit of area traditionally defined as the area of one chain (66 feet) by one furlong (660 feet), equivalent to 43,560 square feet (0.001563 sq mi; 4,047 m²), or about 0.40 hectare.
acre-foot
A customary unit of volume defined as the volume of one acre of surface area to a depth of one foot, commonly used in the United States in reference to large-scale water or soil resources. One acre-foot is equal to 43,560 cubic feet (1,233 m³).
aeroponics
agrarian system
The dynamic set of economic and technological factors that affect agricultural practices in a particular region.
agronomy
The science and technology of producing and using plants for food, fuel, fiber, and land restoration.
algaculture
A specialized branch of aquaculture involving the cultivation of algae, with the goal of producing any of a variety of products that can be used by humans, including food ingredients, fertilizers, colorants and dyes, pharmaceuticals, and chemical feedstock.
biofuel
Any fuel that is produced from recently living biomass, as opposed to fuels produced by slow geological processes such as fossil fuels. Biofuels such as bioethanol and biodiesel are commonly produced from agricultural energy crops.
bioturbation
The mixing and turning of soil caused by organisms moving through the soil.
ecology
The scientific analysis and study of interactions between organisms and their environment. It is an interdisciplinary field that includes biology, geography, and Earth science.
economic maturity
The optimum time at which to harvest a tree or stand of trees (or any other perennial plants), as determined by the age at which the growth rate slows enough to cause the average annual profit over the life of the stand to begin to decrease.^{[citation needed]}
edaphology
The scientific study of the influence of soils on living organisms, particularly plants, and of how soils are used and modified by humans for agriculture.
edge effects
Changes in ecological characteristics (e.g. population or community structure) associated with the boundary between two dissimilar habitat types, ecosystems, or agricultural land uses, potentially affecting the biological and ecological traits of the resident plant or animal communities.