Agriculture Glossary

Abiotic factor

Physical factors such as light, temperature and water

Agroecosystem

The living organisms, physical processes and their interactions in a farming system

Artificial insemination

A form of selective breeding where semen is collected from a chosen male to be inserted artificially into the chosen female to cause her to become pregnant. It also allows semen to be stored for later use or the transport of semen without having to bring the animals together.

Asexual reproduction

Production of new organisms using the genetic material from a single individual. The offspring are genetically identical to the parent

Aspect

The direction something faces in terms of sunlight

Autotroph

An organism that can capture light or chemical energy from the environment to make high-energy substances such as carbohydrates. These can be used to make other molecules such as proteins or they can be broken down in respiration to provide energy. Photoautotrophs capture light in photosynthesis and include plants and algae. Chemoautotrophs include bacteria that capture energy from chemical processes involving substances such as nitrogen and sulphur.

Barrier crops

A crop that is grown around another crop to protect the neighbouring crop, usually by producing a scent that deters the pests.

Bioaccumulation

The increase in concentration of a substance in living tissue as it is absorbed and stored faster than it is broken down and excreted

Biocapacity

A measure of the biological productivity of an area

Biodiversity

A measure of the variety and abundance of wildlife species.

A common quantitative method of measuring biodiversity is Simpson’s Diversity Index.

Biological control

The control of pests using living organisms, usually predators or pathogens.

Biomagnification

The progressive bioaccumulation of a material along a food chain eg organochlorine insecticides, PCBs, heavy metals

Biotic factors

Biological factors such as food supply, predation and disease.

Carnivore

An organism that gains its food energy from eating other heterotrophs

Cellulase

An enzyme that can digest the carbohydrate cellulose

Cellulose

The carbohydrate made of linked glucose molecules which is a major component of plant cell walls and wood. It is a rich source of food energy but no animals can produce the enzyme cellulase that is needed to digest it.

Centre of Diversity

A geographical region with a high plant biodiversity, especially of the wild relatives of crop species.

Cloning

An artificial form of asexual reproduction

Companion crops

These are crops that are grown together to benefit one or both crops by actions such as providing nutrients, controlling pests or attracting beneficial insects.

Contact action (pesticide)

A pesticide that kills pests by coming in contact with them after spraying. Unlike systemic pesticides, they are not absorbed and translocated around the crops

Contour ploughing

A soil erosion control measure where land is cultivated by ploughing horizontal furrows along the contours of the land.

Countryside Stewardship

A scheme where farmers compete for grants for a range of activities that benefit the environment or improved amenity value for the public. This replaced ESS in 2015. (Don’t confuse this with the Countryside Stewardship Scheme)

Countryside Stewardship Scheme

A scheme where farmers could get grants for a range of activities that benefit the environment or improved amenity value for the public. (Don’t confuse this with Countryside Stewardship)

Crop rotation

The practise of growing a different crop in a field on a cycle of three, four or five years

Crop wild relatives (CWRs)

These are wild plant varieties or species that are closely related to domesticated crops. CWRs may contain genetic characteristics that can be used in crop breeding programmes.

Crossbreeding

Producing offspring by mating parents of two different breeds or varieties

DEFRA

Department for Environment, Food and Rural Affairs.

DEFRA is a government department responsible for many issues including environmental protection, agriculture, fisheries and rural communities in the UK. It designates or manages Ramsar Sites, the UK BAP, the Environmental Stewardship Scheme

Efficiency

A measure of the amount of product compared with the inputs usually expressed as a percentage.

Embryo transfer

The transfer of fertilised eggs or embryos from one female to another, such as from a rare species into a female of a closely related species that is more common. This enables more young to be produced than could be achieved through normal breeding. It is also used in livestock breeding.

Endemic pest

A pest that is normally present

Environmental Stewardship Scheme (ESS)

An agri-environmental scheme where farmers receive payments for farm management practices that benefit wildlife and the environment. Higher payments are available for organic farms. Management practices that score points towards the required score include aspects of the management of hedgerows, ditches, field margins, beetle banks, in-field trees and drystone walls. It was replaced by Countryside Stewardship.

Environmentally Sensitive Area

A rural area in which farmers received grants for maintaining the traditional land management methods to protect wildlife and landscape features. It was replaced in 2014 by other agri-environmental schemes.

Enzyme function

Enzymes are protein molecules that enable reactions in cells to take place by reducing the activation energy required for the reaction to occur. Each enzyme is specific to particular reactions.

Enzyme function is inhibited by extreme conditions such as high temperature, low ph or the presence of toxic chemicals.

Epidemic pest

A pest that is not normally a problem but may become a serious pest when the population suddenly increases

Eradication

The reduction of the population of a species by removal or culling

Ethylene

Chemical that stimulates fruit ripening

Extensive agriculture/aquaculture

Agriculture/aquaculture where the yield is achieved with low levels of inputs, often over a large area. Productivity is usually low (yield per unit area) but efficiency is usually high (yield per unit input).

F1 hybrid

The first generation of offspring produced by breeding from two distinct true-breeding varieties. All the offspring have the same combinations of characteristics.

Food conversion ratios (FCRs)

A measure of the efficiency with which an organism converts its food into its own increasing biomass. FCR = mass of food needed to produce one unit of new tissue.

Genetic engineering/genetic modification (GM)

The method of altering an organism’s genetic makeup by artificially introducing genes from another organism, often of another species

GM

Genetic modification

Green Revolution

The agricultural changes since the mid 20th century, where high yielding cereal varieties were bred to increase food production, especially of rice and wheat in tropical LEDCs

Haber Process

The industrial process that combines nitrogen from air with hydrogen from natural gas to produce ammonia from which nitrate fertilisers can be made

Halophyte

An organism that thrives in conditions with a high salt concentration.

Herbivore

An animal that only eats plant food eg cows, sheep

Heterosis

The hybrid vigour produced by breeding between two organisms that are not closely related

Heterotroph

An organism that gains its organic compounds for energy and growth from other organisms eg animals, fungi and many bacteria.

Horizontal gene transfer

The transfer of genetic material between organisms without normal breeding taking place eg the transfer of genes that give pesticide or antibiotic resistance between bacteria

Hybrid

A variety produced by breeding from two different breeds or varieties

Hybrid vigour

The good health achieved by breeding between breeds that are not closely related. This reduces the risk of inbreeding and recessive gene diseases

Inbreeding

This involves breeding between closely related individuals. It increases the risk of recessive genes producing offspring with disadvantageous characteristics.

Inorganic nutrients

Plant nutrients such as compounds of nitrogen and phosphorus eg nitrates and phosphates

Intensive agriculture/aquaculture

Agriculture/aquaculture where the yield is achieved with high levels of inputs. Productivity is usually high (yield per unit area) but efficiency is usually low (yield per unit input).

IR8

A Green Revolution rice variety

Leachate

Drainage water that carries other substances, either in solution or as suspended solids.

LEDC

Less Economically Developed Country

Legumes

Plants with symbiotic nitrogen fixing bacteria in root nodules eg peas and beans.

Limiting factor

An environmental factor present in insufficient amounts to allow a process to occur at a faster rate eg a nutrient being the limiting factor for plant growth

Macronutrient

A plant nutrient needed in large amounts: N, P, K.

Marshall Plan

A US scheme after the 2nd World War to provide food aid to Europe

Maximum Sustainable Yield (MSY)

The greatest amount that can be harvested sustainably

Micronutrient

A nutrient needed in small amounts

Micropropagation

A tissue culture method where large numbers of plants can be produced from a tissue sample from an original plant, without the need for seeds. The young plants may be raised on agar under sterile conditions.

Monoculture

The growth of a single type of crop, usually over a large area

Mulch

Material placed on the soil surface to reduce evaporation losses and reduce weed growth.

Multicropping

A form of polyculture where two or more different crops are grown in an area at the same time.

Mycorrhizal fungi

Symbiotic fungi associated with plant roots that gain carbohydrates from the plants and aid the uptake of nutrients by the plants, such as phosphates from the soil.

Neonicotinoids

A widely used group of insecticides. They have been linked with the deaths of bees, especially when they act synergistically with some fungicides.

NPP

Net Primary Productivity: the energy captured by photosynthesis that is not used in respiration

Nutrient

Any chemical that is essential to an organism for growth or for metabolic processes.

Omnivore

A organism that eats plant and animal foods eg pigs.

Organic nutrients

High-energy nutrients, such as carbohydrates, lipids and proteins from plant or animal material

Organochlorine pesticide

Insecticide group eg DDT, dieldrin, aldrin. Most are now banned or restricted because they are persistent, bioaccumulate and biomagnify.

Organophosphate pesticide

Insecticide group eg parathion, malathion. They are not persistant but have high mammalian toxicity.

Pasture

An area of land used for grazing livestock

Permaculture

An agricultural system that incorporates the principles of natural ecosystems.

Pesticide

A chemical that is used to kill pest species: organisms that damage crops, livestock or cause disease.

Pheremone trap

A trap that attracts organisms using the scent of pheromones. They can be used to try to catch all the members of one gender of a species to stop breeding, but are usually used to show the presence of a pest species.

Pheromone

A chemical released by an organism that changes the behaviour of other members of the same species, especially to attract a mate

Photoautotroph

An organism that produces high-energy food substances using sunlight in photosynthesis.

Ploughing

The cultivation of the soil by turning over the surface layer

Pollination

The transfer of the male plant gamete onto the female part of a flower, resulting in fertilisation and seed production. Pollen may be carried by the wind or by animals such as bees, beetles and moths.

Polyculture

An agriculture/aquaculture system involving the growth of more than one species in the same area at the same time.

Productivity

A measure of the yield of a system, often expressed as the yield per unit area, time or input.

Pyrethroids

Synthetic insecticide pesticides, based on the natural chemicals originally extracted from chrysanthemum flowers (pyrethrins). They are not persistent and have low mammalian toxicity

Quota

A limit set on the number or quantity of items eg milk production (also fish catch)

Rumen

The stomach chamber in which bacteria digest cellulose in ruminants eg cattle, sheep and other large herbivores

Selective breeding

Producing offspring from particular chosen parents, usually to produce offspring with more desirable characteristics

Set Aside Land

Farmland which has been taken out of production and is not cultivated but is kept in a condition where it could be farmed again, for which farmers are paid grants (scheme now closed)

Slash and burn farming

Farming in a forest where a clearing is created by burning, is farmed for a few years until nutrient depletion and weed growth cause it to be abandoned, as a new clearing is created elsewhere.

Sterile male techniques

A method of insect pest control that uses the release of males that have been sterilised. If they mate, no offspring will be produced.

Strip cropping

The growth of more than one crop in alternating narrow strips so that different sowing and harvesting times reduce soil erosion because the whole field is never all bare at the same time.

Sustainable

An activity that can be carried out without making life more difficult for people in the future

Systemic pesticide

A pesticide that is absorbed and transported around a plant in the sap

Tenant farmer

A farmer that rents land from the owner

Terracing

The replacement of a sloping landscape by the creation of a series of narrow horizontal stepped strips, often used to reduce soil erosion.

Tied ridging

A method of reducing soil erosion by creating a grid of raised ridges that cause rainfall to collect, increasing infiltration and reducing runoff.