Back breeding is an approach to livestock breeding and part of a family of de-extinction practices. In back-breeding programs, specimens, for example of certain domestic cattle breeds, are selected for breeding based on traits they are thought to share with an extinct ancestor species. This approach differs from conventional livestock breeding in that it tends to use other breeds and selects for a wider range of traits other than, say, meat or dairy yield. Sometimes, back-breeding projects deliberately avoid traits (such as aggressiveness) even when these are thought to have been present in the extinct species. Depending on when the species went extinct, it can be difficult to trace back its characteristics. Back breeding initiatives tend to rely on a combination of excavations and historical descriptions or depictions (cave drawings or paintings) of the species concerned. Sometimes these projects are based on idealised understandings of the species and do not consider the variety of traits that may have been present among different individuals.

Big food is generally used as a term of criticism, to refer to the most powerful global food industry players. Most commonly it denotes large companies from the food manufacturing, processing and retailing sectors, but can also be used to refer to large agricultural producers as well as companies that provide agricultural inputs such as seeds, fertilisers and pesticides.

Nutrient bioavailability is defined as the fraction of a nutrient in a food that is absorbed and utilised (has an active effect). Essentially, the more bioavailable a nutrient, the more easily it is absorbed and utilised by the body.

Biodiversity refers in the broadest sense to the variety and variability of living organisms in a particular area, or on earth in general. More specifically, the concept is used to denote different aspects of the variety and variability of life, e.g. the number of species in an area (species richness) or the size of species’ populations (species abundance). Biodiversity is measured in different ways and at various scales from the genetic through to the landscape level.

Biodiversity conservation refers to all human activity aimed at the preservation of both the variety and variability of living organisms in a particular area of concern, or on earth in general. People value different aspects of biodiversity in different ways, and can have different priorities in biodiversity conservation e.g. to protect an endemic species or a species that supports an ecological process important to human wellbeing such as pollination.

Biodynamic agriculture is a form of agriculture rooted in the ideas of German philosopher Rudolf Steiner, promoting holistic approaches to farm management, and the use of ecological methods rather than chemical inputs. Its on-farm practices overlap significantly with organic methods. However biodynamic practitioners also emphasise spiritual and mystical elements of human/nature relationships and many use astronomical calendars to guide sowing and harvesting, and fermented herbal remedies to promote plant and soil health and healing. 

Biological nitrogen fixation is the process through which atmospheric nitrogen (N₂) is converted into ammonia (NH₃) or related nitrogenous compounds by bacteria. BNF includes both the fixation of these compounds by bacteria that are present in the soil and by bacteria that live in the root nodules of legumes and certain other plant and tree species. The latter form of BNF is a symbiotic process: the bacteria provide the plant or tree with nitrogen compounds while the plant or tree provides the bacteria with carbohydrates. Nitrogen-fixating plant and tree species are often able to live on relatively poor soils with little need for additional manure or synthetic nitrogen fertiliser. Increased reliance on BNF as opposed to fertilisers is often considered to be an important aspect of a more sustainable food system.

Biomass refers to dry weight of plant-based material that has been harvested or is available on an area of land. Typically, it refers to the use of plants not for food or fibre, but rather for (bio)energy.

Biotechnology is defined by the United Nations as “any technological application that uses biological systems, living organisms, or derivatives thereof, to make or modify products or processes for specific use”. Applied to agriculture, biotechnology involves controversial as well as uncontroversial practices. Examples of biotechnology are the genetic engineering of crops (GMOs), conventional cross-breeding, breeding based on individual plants’ and animals’ genetic traits (molecular marking), cloning animals, and the production of new vaccines using microbiological methods.