Glossary

• Agrochemical

  A chemical such as fertiliser, hormone, pesticide, or soil treatment that improves the production of crops.
• Algal Bloom

  A rapid growth of microscopic algae in water, often resulting in a coloured scum on the surface.
• Aquaculture

  The rearing of aquatic animals or cultivation of aquatic plants for food.
• Bioaccumulation

  The gradual build-up over time of a chemical or heavy metal in a living organism, through absorption via skin, gills or lungs. Build-up occurs either because the chemical is taken up at a rate faster than it can be used or excreted, or because the chemical or heavy metal cannot be metabolised.
• Biological Oxygen Demand

  A measure of the amount of dissolved oxygen used by aerobic micro-organisms when decomposing organic matter in water. Is measured in mg I-1 of oxygen consumed over a 5 day period at 20C.
• Biomagnification

  Arises through consumption of organisms containing bioaccumulated chemicals or heavy metals. The pollutants transfer to the consumer and thus move up through the food chain.
• Crop Rotation

  The practise of growing different crops in succession on the same land, chiefly to avoid depletion of the soil but also to control weeds, diseases and pests.
• Diversification

  This is the branching out from traditional farming by adding new money-making activities such as introducing specialist crops or production methods, offering bed and breakfast, leisure, and recreation activities.
• Eutrophication

  Excessive nutrient enrichment in a waterbody which causes a dense growth of algae or plant life. The algae and surface vegetation prevent life and oxygen penetrating the water, which affects survival of aquatic plants and invertebrates.
• Genetic Modification

  Genetic material which has been altered in a way that does not occur naturally.
• High Yield Varieties

  A crop that has been specially bred or selected to produce more than the natural varieties of the same species.
• Hydroponics

  The cultivation of plants in a soil-less medium or, more commonly, in an aquatic-based environment. Uses mineral nutrient solutions to feed the plants.
• Intensive Agriculture

  Farming that uses a lot of machinery, labour, chemicals, etc in order to maximise crop yield or keep as many animals as possible on a set plot of land.
• Marginal Land

  Land that is of little agricultural value because of problems with access, water control, terrain, environmental restrictions, etc.
• Mechanisation

  The improving of farm labour productivity through use of machinery, implements and tools.
• Metabolisation

  The chemical process by which matter is broken down into simpler substances.
• Nutrient Enrichment

  Excessive inputs of macro-nutrients, e.g. ammonia, into the aquatic environment.
• Persistent Organic Pollutants


  Organic compounds that are resistant to environmental degradation.
• Pollutant

  A substance that contaminates air, water or soil.
• Selective Breeding

  The breeding of plants and animals for particular characteristics.
• Sustainability

  The relationship or balance between social, economic and environmental issues.
• Sustainable Development

  Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
• Trophic Level

  A level or position in a food chain, occupied by a group of organisms that have a similar feeding mode.