Chapter 14 Flashcards
polyculture
planting a mixture of different crops in the same area. this involves planting a mix of perennial grasses, legumes, sunflowers, grain crops, and plants that provide natural insecticides in the same field.
perennials
plant that can live for more than 2 years.
annuals
plant that grows, sets seeds, and dies in one growing season.
industrialized agriculture (high-input agriculture)
uses large amounts of fossil fuel energy, water, commercial fertilizers, and pesticides to produce single crops (monocultures) or livestock animals for sale.
plantation agriculture
is a form of industrialized agriculture used primarily in tropical developing countries. Involves growing cash crops.
traditional subsistence agriculture
typically uses mostly human labor and draft animals to produce only enough crops or livestock for a farm family’s survival.
Tradition intensive agriculture
farmers increase their inputs of human and draft labor, fertilizer, and water to get a higher yield per area of cultivated land.
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.
second green revolution
involves introducing fast-growing dwarf varieties of rice and wheat into several developing countries in tropical and subtropical climates.
interplanting
many traditional farmers simultaneously grow several crops on the same plot.
polyvarietal cultivation
involves planting a plot with several varieties of the same crop.
intercropping
growing two or more different crops at the same time on a plot.
agroforestry (alley cropping)
crops and trees are grown together
polyculture
many different plants maturing at various times are planted together.
land degradation
occurs when natural or human-induced processes decrease the future ability of land to support crops, livestock, or wild species.
soil erosion
the movement of soil components, especially surface litter and topsoil from one place to another.
desertification
the productive potential of arid or semiarid land falls by 10% or more because of a combination of natural climate change that causes prolonged drought and human activities that reduce or degrade topsoil.
salinization
repeated annual applications of irrigation water lead to the gradual accumulation of salts in the upper soil layers.
waterlogging
saturation of soil with irrigation water or excessive precipitation so that the water table rises close to the surface.
soil conservation
involves using ways to reduce soil erosion and restore soil fertility.
conventional-tillage farming
farmers plow the land and then break up and smooth the soil to make a planting surface.
conservation-tillage farming
farmers use it to disturb the soil as little as possible while planting crops.
terracing
can reduce soil erosion on steep slopes by converting the land into a series of broad, nearly level terraces that run across the land contour.
contour farming
involves plowing and planting crops in rows across the slope of the land rather than up and down
strip cropping
involves planting alternating strips of a row crop and another crop that completely covers the soil.
cover crops
the planting of crops such as alfalfa, clover, or rye immediately after harvest to help protect and hold the soil.
windbreaks (shelterbelts)
farms establish to reduce wind erosion, help retain soil moisture, supply wood for fuel, and provide habitats for birds, pest-eating and pollinating insects, and other animals.
organic fertilizer
organic material such as animal manure, green manure, and compost, applied to cropland as a source of plant nutrients.
commercial inorganic fertilizer
commercially prepared mixture of plant nutrients such as nitrates, phosphates, and potassium applied to the soil to restore fertility and increase crop yields.
animal manure
the dung and urine of cattle, horses, poultry, and other farm animals.
green manure
consists of freshly cut or growing green vegetation plowed into the soil to increase the organic matter and humus available to the next crop.
compost
produced when micro-organisms in soil break down organic matter such as leaves, food wastes, paper, and wood in the presence of oxygen.
crop rotation
planting a field, or an area of a field, with different crops from year to year to reduce soil nutrient depletion.
chronic undernutrition
people who cannot grow or buy enough food to meet their basic energy needs suffer.
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.
overnutrition
occurs when food energy intake exceeds energy use and causes excess body fat.
third green revolution
or gene revolution, by using genetic engineering to develop genetically improved strains of crops and livestock animals.
genetic engineering
insertion of an alien gene into an organism to give it a beneficial genetic trait.
genetically modified food
is seen by its producers and investors as a potentially sustainable way to solve world food problems but critics consider it potential dangerous “Frankenfood”
rangelands
are grasslands in temperate and tropical climates that supply forage and vegetation for grazing and browsing animals.
overgrazing
occurs when too many animals graze too long and exceed the carrying capacity of a grassland area.
fisheries
concentrations of particular aquatic species suitable for commercial harvesting in a given ocean area or inland body of water.
aquaculture
to raise marine and freshwater fish like livestock animals in feedlots in ponds and underwater cages and from inland freshwater fishing from lakes, rivers, reservoirs, and ponds.
trawler fishing
his used to catch fish and shellfish that live on or near the ocean floor.
bycatch
most of the fish and other aquatic species are thrown back into the ocean dead or dying.
purse-seine fishing
involves catching surface-dwelling species such as tuna, mackerel, anchovies, and herring, which tend to feed in schools near the surface or in shallow areas.
longlining
involves putting out lines up to 130 kilometers (80 miles) long, hung with thousands of baited hooks.
drift-net fishing
fish are caught by huge drifting nets that can hang as much as 15 meters (50 feet) below the surface and be up to 64 kilometers (40 miles) long.
overfishing
is the taking of so many fish that too little breeding stock is left to maintain numbers
fish farming
involves cultivating fish in a controlled environment and harvesting them when they reach the desired size.
fish ranching
involves holding anadromous species such as salmon that live part of their lives in fresh water and part in salt water in captivity for the first few years of their lives, usually in fenced-in areas or floating cages in coastal lagoons and estuaries.
sustainable (low-input agriculture, organic farming or agroecology)
uses technologies based on ecological knowledge to increase yields, control pests, and build soil fertility.
