Land & Water Use Flashcards
Slash-and-Burn
An area of vegetation is cut down and burned before planted with crops
The fertility they hold is rapidly depleted by deforestation
The farmer must leave the area and find another location
This practice has led to rapid deforestation
Green Revolution
The Green Revolution, or the Third Agricultural Revolution, is the set of research technology transfer initiatives occurring between 1950 and the late 1960s, that increased agricultural production in parts of the world, beginning most markedly in the late 1960s.
Fertilizers & Pesticides
The development of inorganic (chemical) fertilizers brought about the huge increase in farm production
*downsides: reduction of organic matter, oxygen in soil depleted, large amount of energy needed to produce, transport and supply fertilizers + fertilizers that are washed into watersheds are dangerous pollutants
Increased use of pesticides has reduced the number of crops lost to insects, fungi
- downsides: they will only be useful for a short period of time before its target pest evolves to become immune to its effect through natural selection
- new pesticides must constantly be developed
Integrated Pest Management (IPM)
Rather than try to get rid of every pest, IPM tries to keep the pest population down to an economically viable level
Methods include: introducing natural insect predators, intercropping, diversifying crops, and crop rotation
****DOES NOT USE CHEMICALS (Pesticides)
IPM advantage: reduces risks posed to wildlife, human health, and water supply
Disadvantage: complex and expensive
Irrigation
Irrigation techniques: allowed crops to be planted in areas that normally would not have enough precipitation to sustain them
Repeated irrigation: the bad, buildup of salts on the soil’s surface which makes the land unusable for crops
To combat this salinization of the land, farmers begin flooding fields with water to move salt deeper into the soil
Drawback: waterlogs plant roots which kill crops and causes the water table to rise
