Final (Let 12-23) Flashcards
(133 cards)
land use for agriculture
arable land, land for grazing, forest land, other
arable land
land use for growing crops in both permanent (tree crops) and temporary row crops (food and fiber)
land for grazing
pastureland for grazing livestock, either permanent or temporary meadows
forest land
primary forests, naturally regenerated forests, planted forests (logging)
other land use
urban land for buildup of cities, towns, etc.; barren lands like deserts, drylands, salt flats, etc.
extensification
bringing more lands into agriculture to produce more food
deforestation
removal of trees in a forest or tree stand for non-agricultural purposes
shifting agriculture
typically involves the clearing of small plots within forests in Africa, Central America & South America
7 agricultural products driving deforestation
- soybeans
- oil palm
- cattle
- coffee
- cocoa
- rubber
- wood fiber
negative effects of deforestation
- reduced carbon sequestration
- increased chances for wildfires
- increased erosion
- habitat fragmentation
- decreased biodiversity
greenhouse gas emissions
31% from livestock & fisheries
27% from crop production (industry & transportation)
greenhouse gases in agriculture
carbon dioxide, nitrous oxide, methane, ozone, hydrofluorocarbons, per fluorocarbons, sulfurehexafluoride
carbon dioxide (CO2)
74.4%, from running tractors/trucks and powering processing plants, liming and urea application, burning of crop residues
methane (CH4)
17.3%, released by decomposition of organic matter (food waste in landfills), plant matter in rice paddies, storage of manure in lagoons, enteric fermentation of livestock
nitrous oxide (N2O)
6.2%, produced by breakdown of stored manure, bacterial metabolism of nitrogen in soil
agricultural activities that contribute to emissions
- management practice of soil
- livestock digestion
- manure management
- rice cultivation
- burning crop residue
methane from rice production
accounts for more GHG production than any other food crop worldwide
enteric fermentation
A natural part of the digestive process in ruminant animals such as cattle, sheep, goats, & buffalo. microbes in the digestive tract, or rumen, decompose and ferment food, producing methane as a by-product. ~30% of anthropogenic methane is produced by animals for their meat and milk production.
contributions to N2O emissions
fertilizer application, methods of irrigation, tillage
nitrification
ammonia is converted to nitrate
denitrification
microorganisms remove oxygen from the usable forms, and it returns to the atmosphere as nitrogen or nitrous oxide
sources of methane and nitrous oxide
livestock urine and manure when broken down under anaerobic conditions
anaerobic conditions
occurs when animal waste is left in manure piles or in lagoons
properties of healthy soils
- regulating water
- sustaining plant and animal life
- filtering and buffering potential pollutants
- cycling nutrients
- providing physical stability and support