agroforestry Planting trees and crops together.

alley cropping Planting of crops in strips with rows of trees or shrubs on each side.

annual Plant that grows, sets seed, and dies in one growing season. Compare perennial.

aquaculture Growing and harvesting of fish and shellfish for human use in freshwater ponds, irrigation ditches, and lakes, or in cages or fenced-in areas of coastal lagoons and estuaries. See fish farming, fish ranching.

arable land Land that can be cultivated to grow crops. 

Commercial extinction Depletion of the population of a wild species used as a resource to a level at which it is no longer profitable to harvest the species.

drift-net fishing Catching fish in huge nets that drift in the water.

famine Widespread malnutrition and starvation in a particular area because of a shortage of food, usually caused by drought, war, flood, earthquake, or other catastrophic events that disrupt food production and distribution. 

feedlot Confined outdoor or indoor space used to raise hundreds to thousands of domesticated livestock. Compare rangeland. 

fertilizer Substance that adds inorganic or organic plant nutrients to soil and improves its ability to grow crops, trees, or other vegetation. See commercial inorganic fertilizer, organic fertilizer.

fish farming Form of aquaculture in which fish are cultivated in a controlled pond or other environment and harvested when they reach the desired size. See also fish ranching.

fish ranching Form of aquaculture in which members of a fish species such as salmon are held in captivity for the first few years of their lives, released, and then harvested as adults when they return from the ocean to their freshwater birthplace to spawn. See also fish farming.

fishery Concentrations of particular aquatic species suitable for commercial harvesting in a given ocean area or inland body of water. 

gene splicing See genetic engineering. 

Genetic engineering Insertion of an alien gene into an organism to give it a new and usually beneficial genetic trait. Compare artificial selection, natural selection. 

Genetically modified organism (GMO) Organism whose genetic makeup has been modified by genetic engineering. 

green revolution Popular term for introduction of scientifically bred or selected varieties of grain (rice, wheat, maize) that, with high enough inputs of fertilizer and water, can greatly increase crop yields. 

high-input agriculture See industrialized agriculture. 

Industrialized agriculture Using large inputs of energy from fossil fuels (especially oil and natural gas), water, fertilizer, and pesticides to produce large quantities of crops and livestock for domestic and foreign sale. Compare subsistence farming. 

intercropping Growing two or more different crops at the same time on a plot. For example, a carbohydrate-rich grain that depletes soil nitrogen and a protein-rich legume that adds nitrogen to the soil may be intercropped. Compare monoculture, polyculture, polyvarietal cultivation.

interplanting Simultaneously growing a variety of crops on the same plot. See agroforestry, intercropping, polyculture, polyvarietal cultivation.

kwashiorkor Type of malnutrition that occurs in infants and very young children when they are weaned from mother's milk to a starchy diet low in protein. See marasmus, malnutrition. 

low-input agriculture See sustainable agriculture.

macronutrients Chemical elements that organisms need in large amounts to live, grow, or reproduce. Examples are carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur, potassium, calcium, magnesium, and iron. Compare micronutrients. 

malnutrition Faulty nutrition, caused by a diet that does not supply an individual with enough protein, essential fats, vitamins, minerals, and other nutrients needed for good health. See awashiorkor, maramus. Compare overnutrition, undernutrition.

marasmus Nutritional deficiency disease caused by a diet that does not have enough calories and protein to maintain good health. See kwashiorkor, malnutrition. 

micronutrients Chemical elements organisms need in small or even trace amounts to live, grow, or reproduce. Examples are sodium, zinc, copper, chlorine, and iodine. Compare macronutrients. 

monoculture Cultivation of a single crop, usually on a large area of land. Compare polyculture, polyvarietal cultivation. 

net primary productivity (NPP) Rate at which all the plants in an ecosystem produce net useful chemical energy; equal to the difference between the rate at which the plants in an ecosystem produce useful chemical energy (gross primary productivity) and the rate at which they use some of that energy through cellular respiration. Compare gross primary productivity. 

nutrient Any food, element, or compound an organism must take in to live, grow, or reproduce.

organic farming Producing crops and livestock naturally by using organic fertilizer (manure, legumes, compost) and natural pest control (bugs that eat harmful bugs, plants that repel bugs, and environmental controls such as crop rotation) instead of using commercial inorganic fertilizers and synthetic pesticides and herbicides. See sustainable agriculture. 

overfishing Harvesting so many fish of a species, especially immature fish, that not enough breeding stock is left to replenish the species, such that it is not profitable to harvest them. 

overgrazing Destruction of vegetation when too many grazing animals feed too long and exceed the carrying capacity of a rangeland or pasture area. 

overnutrition Diet so high in calories, aturated (animal) fats, salt, sugar, and processed foods and so low in vegetables and fruits that the consumer runs high risks of diabetes, hypertension, heart disease, and other health hazards. Compare malnutrition, undernutrition.

pasture Managed grassland or enclosed meadow that usually is planted with domesticated grasses or other forage to be grazed by livestock. Compare feedlot, rangeland. 

perennial Plant that can live for more than 2 years. Compare annual. 

Plantation agriculture Growing specialized crops such as bananas, coffee, and cacao in tropical developing countries, primarily for sale to developed countries. 

polyculture Complex form of intercropping in which a large number of different plants maturing at different times are planted together. See also intercropping. Compare monoculture, polyvarietal cultivation.

polyvarietal Planting a plot of land with several varieties of the same crop. Compare cultivation intercropping, monoculture, polyculture. 

Primary productivity See gross primary productivity, net primary productivity.

rangeland Land that supplies forage or vegetation (grasses, grasslike plants, and shrubs) for grazing and browsing animals and is not intensively managed. Compare feedlot, pasture.

riparian rights System of water law that gives anyone whose land adjoins a flowing stream the right to use water from the stream, as long as some is left for downstream users. Compare prior appropriation.

riparian zones Thin strips and patches of vegetation that surround streams. They are very important habitats and resources for wildlife. 

ruminants Grazing animals with complex digestive systems that enable them to convert grass and other roughage into meat and milk. 

Subsistence farming Supplementing solar energy with energy from human labor and draft animals to produce enough food to feed oneself and family members; in good years there may be enough food left over to sell or put aside for hard times. Compare industrialized agriculture.

Sustainable agriculture Method of growing crops and raising livestock based on organic fertilizers, soil conservation, water conservation, biological pest control, and minimal use of nonrenewable fossil fuel energy.

sustainable yield (sustained yield) Highest rate at which a potentially renewable resource can be used without reducing its available supply throughout the world or in a particular area. See also environmental degradation. 

terracing Planting crops on a long, steep slope that has been converted into a series of broad, nearly level terraces with short vertical drops from one to another that run along the contour of the land to retain water and reduce soil erosion. 

Traditional intensive agriculture Producing enough food for a farm family's survival and perhaps a surplus that can be sold. This type of agriculture uses higher inputs of labor, fertilizer, and water than traditional subsistence agriculture. See traditional subsistence agriculture. Compare industrialized agriculture.

Traditional subsistence agriculture Production of enough crops or livestock for a farm family's survival and, in good years, a surplus to sell or put aside for hard times. Compare industrialized agriculture, traditional intensive agriculture.

undergrazing Reduction of the net primary productivity of grassland vegetation and grass cover from absence of grazing for long periods (at least 5 years). Compare overgrazing. 

undernutrition Consuming insufficient food to meet one's minimum daily energy needs for a long enough time to cause harmful effects. Compare malnutrition, overnutrition.