Chapter 7 Flashcards
What is the green revolution?*
It helped preserve biodiversity by preventing deforestation and habitat destruction
What is subsistence farming?*
Self-sufficient farming where farmers grow enough food to feed themselves and their families.
How much is food consumption predicted to increase by 2020?*
50%
How much is food production predicted to increase in the next two decades?*
40%
What are genetically modified crops?*
Crops that have had their DNA altered in a way that does not occur naturally
What does transgenics mean?*
The incorporation of desired traits into crop lines and animals.
4 commonly occurring GM crops
soybeans, corn, cotton, and canola
What are the benefits of GM organisms
disease resistance, drought tolerant, improved nutritional value, less allergens, more productivity
Environmental issues associated with GM crops
not considered safe by all people, not affordable everywhere, and affects non-target species
Roundup Ready
Genetically modified crops like soybeans and canola that are resistant to roundup.
How do pest populations develop resistance to pesticides?
The pests that survive the pesticide breed and produce a pesticide-resistant population.
What is food security?
The guarantee of an adequate, safe, nutritious, and reliable food supply available to all people at all times.
Undernutrition
Receiving fewer calories than the minimum dietary energy requirement.
Overnutrition
Consuming too many calories in a day.
Malnutrition
When a person fails to obtain enough proteins, lipids, vitamins, and minerals.
What is the root cause of hunger?
The root cause of hunger is poverty.
Causes of famine
Civil wars, drought, government incompetence, illiteracy, discrimination.
True or false, food aid alleviates chronic hunger, helps local agriculture, disrupts local economy, contributes to ecological deterioration, postpones the day of reckoning
True
What is soil?
A complex mixture of organic and inorganic components and is full of living organisms.
By volume, what does soil consist of?
50% mineral matter, 5% organic matter, the rest is air or water.
How long can it take to form 1 inch of soil?
Hundreds or thousands of years.
Distinguishing characteristics of soil (5)
Slow rate of nutrient and energy transfer, different textures demand different adaptions, near total reliance on decomposers, exclusive use of detritus, extreme susceptibility to disturbance and slow recovery times.
What is the parent material of soil?
The base geological material in a particular location.
What is soil texture?
The percentage of each type of particle found in the soil.
How big are sand particles?
Large
How big are silt particles?
Medium/small
How big are clay particles?
Small
Loam soil is approximately
40% sand, 40% silt, and 20% clay.
What is humus?
Partly decomposed organic matter. Has a high capacity for holding water and nutrients.
Why is humus important?
Without humus, it results in topsoil mineralization, loss of water holding and nutrient holding capacity, water infiltration, and aeration.
What defines productive soil? (7) low salt content
A good supply of nutrients, water & nutrient holding capacity, resists evaporation, porous structure, neutral ph, low salt content
Splash erosion
Impact of falling raindrops breaks up the clumpy structure of topsoil.
Sheet erosion
Erosion caused by running water.
Gully erosion
When erosion creates gullies by moving large amounts of soil.
6 things that can cause erosion
Overcultivating, overgrazing, construction, deforestation, salination, waterlogging.
What happens after soil erosion?
Loss of fertility and sedimentation.
Sedimentation
When eroding soil fills reservoirs, streams, estuaries, and bays.
Desertification
When water-holding capacity of soil is greatly diminished.
According to the TED talk, how can we prevent desertification?
We can use livestock and their predators to mimic nature.
How does vegetation prevent erosion?
It can slow runoff and allow it to flow above the soil. It can also help absorb impact from raindrops and roots hold soil together,
Farm bills
Federal Agriculture Improvement and Reform Act (FAIR), Wetlands Reserve Program, 2002 Farm Security and Rural Investment Act, Wildlife Habitat Incentives Program (WHIP).
Subsidies
Sustainable agriculture: SARE Sustainable Agriculture Research and Education
Positive effects of erosion
Dust settles in new regions, brings nutrients and minerals to oceans, stimulates clouds, and brings new organisms to islands.
What are soil profiles?
From surface to bedrock, is known as a soil profile.
What is the best approach for making an agricultural system more sustainable?
Mimicking the way a natural ecosystem functions.
How do ecosystems function?
They operate in cycles and are internally stabilized with negative feedback loops.
What were the consequences of the Green Revolution?
It created a heavy reliance on machinery, irrigation, and fertilizers, and had a negative impact on small farmers and culturally specific crops.
Explain the importance of soils to agriculture
Nutrients move from the soil into plants and animals we eat.
Kwashiorkor
A disease that is caused by a diet high in starch but low in protein.
Marasmus
Protein deficiency and a lack of calories which causes wasting or shriveling.
Monocultures
Mixtures of different crops in small plots of farmland and is exclusive to industrial farming.
Polycultures
Mixtures of different crops in small plots of farmland and is exclusive to traditional farming.
Alfisols (f for fertile)
Fertile soil with a layer of clay. Found from south Texas to Michigan.
Andisols
Formed from volcano ash. High in glass grains, water absorbent. In Hawaii and Northwest Cascade region
Aridisols
Soils in dry regions. High in calcium, with layers of clay, silica, salt and gypsum. 8% of U.S. soil.
Entisols
Immature soil. Hillsides and shorelines. Soils that don’t fit in other categories are classified here.
Gelisols
Permafrost. Contains a lot of carbon because of things that do not decompose quickly. Found in Alaska.
Histosols
Found in places with a lot of water like the Gulf Coast and Great Lakes.
Inceptisols
More aged than entisols but have no characteristics of other soils. Found in the Rocky Mountains and Appalachian Mountains.
Mollisols (like moles in grasslands)
Dark and rich. Grasslands. Very fertile. Found in Great Plains.
Oxisols
Oxidized. Tropical rainforests. Not fertile due to water leeching. High in aluminum and iron. Hawaii.
Spodosols (like spores in the forest)
Acidic. Due to water leeching. Coniferous forests. Not fertile.
Ultisols
Similar to spodosols but contains a layer of clay. High in iron.
Vertisols (v for volume)
Clay-rich soil. Swells and shrinks. Volume of soil depends on water.
Thomas Malthus
One of the first to predict we would outrun the food supply.
What types of food security are there?
Family, country, and global.
Leaching
When solid particles suspended in liquid or dissolved in liquid are transported to another location. Normally due to gravity.
O horizon
Organic, litter layer.
A horizon
topsoil, organic mixed with mineral components
E horizon (e for leeching)
leaching layer.
B horizon
subsoil, where minerals from the E horizon settle.
C horizon
weathered parent material
R horizon (rock)
pure parent material or bedrock.
Norman Borlaug (wheat)
Bred a high-yielding, disease resistance wheat that helped boost agriculture in many developing countries.
Bedrock
The continuous mass of solid rock that makes up earth’s crust.
Topsoil
Inorganic mineral matter mixed with organic matter and humus.
Swidden agriculture
a traditional from of agriculture in tropical forested areas
Slash-and-burn
Tropical rainforests aren’t very fertile, so they are cut and burned to restore nutrients before planting crops.
Waterlogging
When overirrigation causes the water to drown plant roots, depriving them of oxygen.
Salinization
The buildup of salts in surface soil layers.
Precision agriculture
Uses technology to monitor crop conditions and maximize production while minimizing waste.
Soil degredation
When soil loses quality and productivity due to forest removal and overgrazing.
Deposition
Occurs when eroded material is deposited in a new location
Natural Resources Conservation Service (SCS) - a model
A model for other nations that established their own soil conservation agencies to aid farmers in fighting soil erosion
Conservation Reserve Program (CRP) a farm bill
A farm bill that pays farmers to stop cultivating highly erodible cropland and place it in conservation reserves planted with grasses and trees.
How is climate change already affecting food production in Kenya?
Droughts in parts of Kenya have become four times more likely in the last 25 years.
How is oil related to the production of food?
Oil is used for machines used in agriculture, cooking, and processing.
How will a shortage of water affect our food supply?
We use a lot of water to grow our foods. Water could become harder and harder to find.
Why has the government of Senegal allowed other countries to fish off the coast whenever their people don’t have enough income and food?
Because they get paid to. Senegal is one of the poorest countries in the world.
What are benefits and environmental concerns of Bt corn?
It is engineered to include a gene from the micro-organism Bacillus thuringiensis, which produces a toxin that protects crops from pests but it has been affecting the mortality and growth of caddisflies.
Which natural resources are in competition with biofuels?
Land, food, and water.
Which of the following is NOT classified as a renewable source of energy?
Natural gas.
True or false, secondary succession relates to the establishment and development of an ecosystem where one did not previously exist
False
Extinction is _____
A natural process
The major force(s) causing the genetic divergence of the two populations is/are:
Mutation and natural selection
The two processes that determine the world’s current biodiversity are:
Allopatric and sympatric speciation
Consider a situation where increased solar radiation reaches the Earth’s surface and raises the oceans temperature. This results in more evaporation, which produces more clouds. The increased cloud cover reduces the amount of solar radiation that reaches the surface of the Earth. This is an example of:
Negative feedback
Owls and hawks prey on similar animals, but hawks hunt by day and owls hunt by night. This is an example of
Niche differentiation
If A increases and causes an effect on B, which in turn causes an increase in A, is that _____.
Positive feedback
Please name 3 things which can have an albedo higher than 50%
Fresh snow, mirror, and aluminum foil
What does species richness refer to?
The total number of species represented in a community
