APES Unit 5 Part 1

Tragedy of Commons

Suggests that individuals will use shared resources in their own self-interset rather than keeping with common good, thereby depleting the resources.

Externalities

Negative costs associated with human actions, that aren’t accounted for in the price (unintended side-effects)

green revolution 

shift in agriculture away from small, family owned farms to large, industrial scale agribusiness 

positive effects of the green revolution 

greatly increases efficiency of lands, short-term profitability, and food supply; decreased world hunger and increased earth’s carrying capacity for humans 

negative effects of the green revolution

soil erosion, biodiversity loss, ground and surface water contamination

mechanization

increasing use of tractors for plowing and tilling of fields

positives and negatives of mechanization of farming 

positive is increases yield and profits, negative is increased reliance on fossil fuels and makes topsoil more prone to erosion 

high yield variety crops

hybrid, or genetically modified crops that produce a higher yield (amount of crop produced per unit of area)

GMOs

genetically modified crops that have genes for drought tolerance, pest resistance, faster growth, and larger fruit/gain

positives and negatives of GMOs 

positives are increased profitability with fewer plants lost to drought, disease, or pests, and larger plant sizes; negatives are decreased diversity and susceptibility to diseases as GMO crops are genetically identical 

synthetic fertilizer

part of green revolution with shift from organic fertilizers (like manure and compost) to synthetic fertilizers

positives and negatives of synthetic fertilizer

positive is increased yield and profits with more key nutrients added to soil, negatives are excess nitrate and phosphate washing into water and causing eutrophication and fossil fuel use for production

irrigation

drawing water from the ground or nearby surface waters and distributing it on fields to increase plant growth 

positives and negatives of irrigation

positive is it makes agriculture possible in many parts of the world that are naturally dry; negatives are it depletes groundwater and causes soil salinization

pesticides

chemicals sprayed on crops that kill weeds, insects, rodents and pests that eat or damage crops 

positives and negatives of pesticides

positive is increased yield and profits with fewer plants lost to pests, negatives are it can wash off crop s in runoff and kill or harm non-target species in local soil or water

monocropping 

growing one single species (corn, wheat, soy) of crop. High efficient for harvest, pesticide, and fertilizer application 

negative impacts of monocropping

decreases biodiversity, increases soil erosion (as all crops are harvested at once so soil is left bare) and decreases habitat diversity for species living in the area

agricultural practices that can cause environmental damage 

tilling, slash and burn farming, and the use of fertilizers 

tilling

mixing and breaking up soil to make planting easier, also loosens soil for roots

negative impacts of tilling 

increases erosion by loosening topsoil, loss of organic matter and topsoil nutrients over time, and increased particulate matter in air and sediments in nearby water 

slash and burn

cutting down vegetation and burning it to clear land for agriculture and return nutrients in plants to soil 

negative impacts of slash and burn

deforestation, releases greenhouse gases, increases particulate matter in air, and lower albedo making area warmer

synthetic (inorganic) fertilizers

fertilizers which don’t return organic matter to soil, no increased water holding capacity and no soil decomposers

negative impacts of soil fertilizers

leaching and runoff

most efficient irrigation method

drip irrigation

furrow irrigation

trench dug along crips and filled with water; easy and inexpensive, 66% efficient and remaining lost to runoff and evap

drip irrigation 

most efficient method, holes in hose allow water to slowly drip out, avoids waterlogging and conserves water, over 95% efficient 

flood irrigation

flood entire field; easier but more disruptive to plants, can waterlog soil and drown plants, 80% efficient, last 20% lost to runoff and evap

spray irrigation

ground or surface water pumped into spray nozzles, more expensive as energy required for pumps and sprinklers, 75% efficient

waterlogging 

overwatering can saturate the soil, filling all soil pore space with water, depriving roots of oxygen

solution to waterlogging

drip irrigation/soil aeration- poking holes or cores in soil to allow air in and water to drain through soil

soil salinization

groundwater used for irrigation has small amounts of salt, so when water evaporates there is salt left behind in soil and overtime it reaches toxic levels, dehydrating plant roots and preventing growth

global human water use composition

agricultural 70%, industrial 19%, municipal 11%

aquifers

useable groundwater deposits for humans replenished by groundwater recharge when rain makes its way down

unconfined aquifers 

have rapid groundwater recharge 

confined aquifers

long-term water deposits with slow recharge 

depletion of aquifers causes

saltwater intrusion (near coast) and cone of depression (possible in all areas)

saltwater intrusion

excessive pumping near coast lowers water table pressure, allowing saltwater to seep into groundwater

cone of depression

forms when water table is lowered by excessive pumping, depleting water and drying nearby wells, can occur in aquifers in all areas 

CAFO (concentrated animal feeding operation) 

Also called feedlots- densely crowded method where animals are fed grain (corn) to raise them as quickly as possible 

manure lagoons 

large, open storage pits for animal waste (manure). Waste contains ammonia, hormones, antibiotics; heavy rain can flood these lagoons and contaminate nearby surface and groundwater with runoff 

free range grazing

animals graze on grass & grow at natural rate without growth hormones

positives and negatives of free range grazing

positives are no need for antibiotics with dispersed population, doesnt require production of corn to feed animals, waste is dispersed over land naturally; negatives are requires more total land use per pound of meat so more expensive to consumer

overgrazing

too many animals grazing in area of land can remove all vegetation which leads to topsoil erosion and desertification. solution is rotational grazing (moving animals periodically) to prevent overgrazing

3 areas of inefficiency of meat

energy (requires energy to plant, grow, and harvest plants to feed animals along with energy to bring water, animals, house animals, slaughter them and package), land (all the land needed to grow plants to feed animals plus room the animals take up) and water (all the water for crops that animals eat plus the water animals drink).

ecological footprint 

measure of how much a person/group consumes, expressed in area of land 

factors of ecological footprint (land required for this stuff)

food production, raw materials, housing, electricity production, disposing waste (landfill space)

carbon footprint

measured in tones of CO2 produced per year as opposed to measured in land as in ecological footprint

sustainability 

consuming a resource of using a space in a way that does not deplete or degrade it for future generations (ex using compost which is renewable over synthetic fertilizer which uses fossil fuels) 

maximum sustainable yield

the max amount of a renewable resource thta can be harvested without reducing or depleting the resource ofr future use; rougly ½ of carrying capacity