Agriculture A linked, dynamic social-ecological system based
on the extraction of biological products and services from
an ecosystem, innovated and managed by people. It thus
includes cropping, animal husbandry, fishing, forestry,
biofuel and bioproducts industries, and the production
of pharmaceuticals or tissue for transplant in crops and
livestock through genetic engineering. It encompasses all
stages of production, processing, distribution, marketing,
retail, consumption and waste disposal.
Agricultural biodiversity Encompasses the variety and vari-
ability of animals, plants and microorganisms necessary
to sustain key functions of the agroecosystem, its struc-
ture and processes for, and in support of, food produc-
tion and food security.
Agricultural extension Agricultural extension deals with the
creation,  transmission  and  application  of knowledge
and skills designed to bring desirable behavioral changes
among people so that they improve their agricultural
vocations and enterprises and, therefore, realize higher
incomes and better standards of living.
Agricultural innovation Agricultural innovation is a socially
constructed process. Innovation is the result of the inter-
action of a multitude of actors, agents and stakeholders
within particular institutional contexts. If agricultural re-
search and extension are important to agricultural inno-
vation, so are markets, systems of government, relations
along entire value chains, social norms, and, in general,
a host of factors that create the incentives for a farmer to
decide to change the way in which he or she works, and
that reward or frustrate his or her decision.
Agricultural population The agricultural population is de-
fined as all persons depending for their livelihood on
agriculture, hunting, fishing or forestry. This estimate
comprises all persons actively engaged in agriculture and
their non-working dependants.
Agricultural subsidies Agricultural subsidies can take many
forms, but a common feature is an economic transfer,
often in direct cash form, from government to farmers.
These transfers may aim to reduce the costs of produc-
tion in the form of an input subsidy, e.g., for inorganic
fertilizers or pesticides, or to make up the difference
between the actual market price for farm output and a
higher guaranteed price. Subsidies shield sectors or prod-
ucts from international competition.
Agricultural  waste Farming wastes,  including  runoff  and
leaching of pesticides and fertilizers, erosion and dust
from plowing, improper disposal of animal manure and
carcasses, crop residues and debris.

Agroecological Zone A geographically delimited area with
similar climatic and ecological characteristics suitable for
specific agricultural uses.
Agroecology The science of applying ecological concepts and
principles to the design and management of sustainable
agroecosystems. It includes the study of the ecological
processes in farming systems and processes such as nutri-
ent cycling, carbon cycling/sequestration, water cycling,
food chains within and between trophic groups (microbes
to  top   predators),   lifecycles,   herbivore/predator/prey/
host interactions, pollination, etc. Agroecological func-
tions are generally maximized when there is high species
diversity/perennial forest-like habitats.
Agroecosystem A  biological   and   biophysical  natural  re-
source system managed by humans for the primary pur-
pose of producing food as well as other socially valuable
nonfood goods and environmental services. Agroecosys-
tem function can be enhanced by increasing the planned
biodiversity (mixed species and mosaics), which creates
niches for unplanned biodiversity.
Agroforestry A dynamic, ecologically based, natural resources
management system that through the integration of trees
in farms and in the landscape diversifies and sustains
production for increased social, economic and environ-
mental benefits for land users at all levels. Agroforestry
focuses on the wide range of work with trees grown on
farms and in rural landscapes. Among these are fertilizer
trees for land regeneration, soil health and food security;
fruit trees for nutrition; fodder trees that improve small-
holder livestock production; timber and fuelwood trees
for shelter and energy; medicinal trees to combat disease;
and trees that produce gums, resins or latex products.
Many of these trees are multipurpose, providing a range
of social, economic and environmental benefits.
AKST Agricultural    Knowledge,    Science    and    Technology
(AKST) is a term encompassing the ways and means used
to practice the different types of agricultural activities,
and including both formal and informal knowledge and
technology.
Alien Species A species occurring in an area outside of its
historically known natural range as a result of intentional
or accidental dispersal by human activities. Also referred
to as introduced species or exotic species.
Aquaculture The farming of aquatic organisms in inland and
coastal areas, involving intervention in the rearing pro-
cess to enhance production and the individual or corpo-
rate ownership of the stock being cultivated. Aquaculture
practiced in a marine environment is called mariculture.