Agricultural Math & Energy
if a cafo cow needs 10 kg of grain to make 1 kg of meat and 1 hectare makes 10,000 kg of grain how much meat do you get per hectare
1,000 kg
using broad spectrum pesticides all the time leads to this evolutionary issue where farmers have to keep using stronger chemicals because the bugs survive and reproduce
pesticide resistance or the pesticide treadmill
runoff from cafo manure lagoons dumps a ton of nitrogen and phosphorus into local water which triggers what oxygen depleting biological process
eutrophication
the collapse of the atlantic cod fishery is a perfect example of what environmental economics concept where people deplete a shared unregulated resource for their own gain
tragedy of the commons
The green revolution massively increased crop yields by moving away from polyculture to what risky practice of planting just one crop species over a huge area
monocropping or monoculture
What specific farming requirement accounts for the largest chunk of fossil fuel use in agriculture at roughly 31 percent
fertilizer
if researchers are testing a new pesticides toxicity on aquatic life and measure the concentration where half the test subjects die what is that data point called
ld50
cows and sheep release a ton of this greenhouse gas through enteric fermentation in their stomachs and it has a way higher global warming potential than co2
methane
turtle excluder devices are required by law on commercial shrimp nets in the us to stop what specific problem
bycatch
Relying too much on groundwater irrigation in hot dry places causes water to evaporate fast and leave toxic minerals behind. what is this soil ruining process called
Soil salinization
industrial farming uses insane amounts of fossil fuels to make synthetic fertilizers. what element is artificially fixed from the atmosphere into a bioavailable form using the haber bosch process
Nitrogen
if someone sees male frogs with hermaphroditic traits next to a cornfield which endocrine disrupting herbicide is probably to blame since its used so much in the us
atrazine
what is constantly given to cafo animals in their feed to make them grow fast and not get sick in cramped spaces which is now causing a massive human health crisis
antibiotics
what are the specific zones called where human activity and fishing are totally limited or banned so depleted fish populations can actually recover
MPAS or marine protected areas
Planting roundup ready soybeans lets farmers spray whole fields with weed killer without killing the actual crop which is possible because of what technology
GMOS or genetic engineering
you spray a pesticide on a 500 hectare farm at 2 liters per hectare. if the half life means it drops by 50 percent every 10 days how much is left in the soil after 20 days
250 liters (1,000L initial -> 500L after 10 days -> 250L after 20 days)
instead of spraying chemicals if you release parasitic wasps to kill off aphids what specific integrated pest management technique is that
biological control
shifting people from eating mostly meat to a plant based diet increases the carrying capacity of the land because it skips the massive energy losses described by what ecological rule
The 10 percent rule
what commercial fishing method drags a super heavy net across the sea floor to catch fish like flounder but ends up destroying coral reefs and sea grass
Bottom trawling
Mechanically tilling the soil before planting might increase yields at first but it leads to what major environmental issue that ruins the o and a soil horizons
Topsoil erosion
using the 10 percent rule if a person eats 2,000 kcal of farmed salmon roughly how many kilocalories of phytoplankton were needed at the bottom of the food chain to support that
HINT: (Human <- Salmon <- Small fish <- Zooplankton <- Phytoplankton)
20,000,000 kcal (Human 2k <- Salmon 20k <- Small fish 200k <- Zooplankton 2M <- Phytoplankton 20M)
what is the biggest downside of switching from conventional farming to ipm that makes it hard for massive corporate farms to do it
it takes way more monitoring and expert labor
to stop soil erosion and desertification on rangelands what method can ranchers use where they move livestock between different areas so the grass can recover
rotational grazing
aquaculture is supposed to save wild fish but farming carnivorous fish like salmon actually makes wild fish depletion worse because of what specific requirement
they have to be fed wild caught forage fish like fishmeal
To stop waterlogging and salinization while saving a ton of water what highly efficient but expensive irrigation system can farmers use to deliver water right to the plant roots
Drip irrigation