Unit 6: Food and agriculture Flashcards
Benefits of Mechanization
- less reliant on human labor
- machinery used can be specialized and targeted for individual tasks
- efficiency: operations on farm happen more quickly and consistently -> higher yield of crops in shorter time
Drawbacks of Mechanization
- all of your machines operate on soil and gas
- soil can be overworked and may erode and compact more -> soil fertility declines
Benefits of Monocultures
- Efficiency: “ease” with planting and harvesting - same type of fertilizer, same amounts of water
Drawbacks of Monocultures
- loss of biodiversity (esp genetic diversity)
- this leads to vulnerability in defense against pests and diseases
Synthetic Fertilizer
- Efficiency: Can be formulated to have certain nutrients in precise amounts (targeted use)
- Is water soluble and will run off into nearby bodies of water (can lead to algal blooms)
Organic Fertilizer
- improves soil structure -> improves water holding capacity
- feeds microbes in soil -> increases soil fertility
- can be more expensive and more difficult to handle/transport etc
Benefits of Pest Control
- helps to maximize crop yield (provides short-term protection of crops so that they survive infestation)
- can be formulated or customized to kill all types of pests (weed, insects, fungi)
- efficiency: mass produce, easier to distribute/deliver to crops with mechanization in place
Drawbacks of Pest Control
- kills non-target species (organisms that are not the pests) -> biodiversity declines
- animal health impacts include:
irritation of the ears, nose, and throat
endocrine disruptors (interfere with hormone activity)
Integrated Pest Management (IPM)
- Reduce (not necessarily eliminate) the use of pesticides so to minimize impacts on non-target species and humans
- Reduce (not eliminate) the pests to a manageable level
- A combination of physical, biological, and limited chemical methods such as crop rotation, incorporating natural predators of pests, using mulch, intercropping, etc.
- This approach is more sustainable in terms of managing pests but can be complex and expensive to execute.
Flood Irrigation
- soaking the ground with water
- inexpensive and easier to do compared to other methods
- around 30% water is lost to evaporation
- rice is grown this way
- soil can get waterlogged
Furrow Irrigation
- series of channels (furrows) dug between crop rows which are then flooded with water
- inexpensive and easier to do compared to other methods
- around 30% water is lost to evaporation
- corn is grown this way
Spray Irrigation
- uses large sprinkler systems that roll back and forth across a field or rotate around a center pivot
- more expensive but more efficient
- requires the use of fossil fuels
- around 25% water is lost to evaporation
Drip Irrigation
- uses perforated hoses to release small amounts of water to roots
- most efficient method
Waterlogging
Too much water is in the soil due to overwatering; can drown the plant
How to remediate the issues of waterlogging?
- switch to drip irrigation
- poke holes or cores in the soil to allow air in and water to drain through the soil
Salinization
- Salts in groundwater remain in the soil and build up there after the water evaporates
- Can be toxic to plants over time
- high salt concentrations in the soil cause water to move out of plant cells through osmosis, leading to dehydration and nutrient imbalances (water potential outside plant cells decreases)
How to remediate the issues of salinization?
a combination of drip irrigation, soil aeration, flushing with fresh water, switching to fresh(er) water sources
Aquifer Overuse
Aquifers can be severely depleted if overused for agricultural irrigation
ex: Ogallala Aquifer
Artificial Selection (a.k.a. “selective breeding”)
- Has taken place over thousands of years via the domestication of animals & cultivation of plants with desirable traits
- artificial selection works the same way as natural selection, except we are choosing which traits to enhance nad propagate in future generations.
Genetic Modification - GMOs
- More recent phenomenon where speed and precision of selective breeding are enhance
- scientists can now target and isolate specific genes that will make crops grow larger, be resistant to pests, or produce a higher yield.
- The use of genetic engineering, or genetically modified organisms (GMOs), is prohibited in organic products.
Benefits of GMOs
- produce crops that are more resistant/tolerant to extreme conditions such as drought, heat, and salt so able to grow crops in more places
- produce crops that can make their own pesticides (ex: Bt corn) so synthetic applications can be applied less often
Drawbacks of GMOs
- reduction in genetic diversity if all the crops are modified in the same fashion
- unintended artificial selection may occur where pests become resistant overtime
- moral/ethical qualm on the roles humans play in the selection process and issues with intellectual property and patent rights
Benefits of Concentrated Animal Feeding Operations (CAFOs)
- also referred to as “feedlots”
- By keeping animals confined, farmers minimize costs associated with land, water, and feed.
- This translates to lower prices for the consumer
- Operations are generally efficient (livestock are one place, one type of feed, etc…)
Drawbacks of Concentrated Animal Feeding Operations (CAFOs)
- Antibiotics: increase in antibiotic-resistant strains of microorganisms
- Animal waste:
- can cause excess nutrient runoff to nearby lakes and ponds (leads to algal blooms)
- contains fecal coliform bacteria -> water is then contaminated when animal waste runs off
Benefits of Free-Range Grazing
- Livestock roam over large areas and graze on grass and other greens for their entire lives
- animals are free from antibodies and hormones
- waste is not pooled, but spread out (serves as nutrient rich fertilizer)
- diet is more nutritious (grass fed)
Drawbacks of Free-Range Grazing
- more expensive because it uses more land and more times to get to market size
- Overgrazing leads to loss in vegetation -> soil erosion and desertification (the process by which vegetation in drylands i.e. arid and semi-arid lands, such as grasslands or shrublands, decreases and eventually disappears)
but this can be remediated by rotational grazing
Less consumption of meat could lead to?
- Increase efficiency in land and water use (use less of both)
- decrease presence of disease and antibiotic resistant bacteria
- Reduce greenhouse gas emissions
(CH4 from cows and N2O from decomposing animal waste)
Bycatch
the unwanted fish and other marine organisms that are caught during commercial fishing operations, but are not harvested or sold
Bottom Trawl
Cone-shaped nets dragged along the seafloor to catch species like cod, halibut, and shrimp.
Environmental Impacts:
- High levels of bycatch.
- Damage to fragile seafloor habitats from heavy gear.
- Disrupts benthic ecosystems (ecosystems at the bottom of the ocean).
- Reduces biodiversity in affected areas
Helped by: restrictions on trawling locations and times, along with gear modifications that allow non-target marine life to escape and minimize seafloor damage
Dredge
Metal, cage-like devices with features like rakes or hydraulic jets used to harvest clams, oysters, and scallops.
Environmental Impacts:
- Significant harm to sensitive seafloor habitats.
- Destruction of bottom-dwelling species.
- Sediment disruption can degrade water quality and harm aquatic ecosystems
Helped by: Limiting dredging areas
Gillnetting
Stationary or drifting mesh walls designed to capture fish by entangling them.
Environmental Impacts:
- High bycatch risk, including sea turtles, marine mammals, and sharks.
- Potential entanglement of protected species.
- Ghost nets (lost nets) continue to trap marine life.
Helped by: nets can be deployed deeper in the water column to allow animals to pass over, and pingers can be added to alert passing marine mammals
Longlining
Longlines with baited hooks stretched for miles, targeting species like tuna and swordfish
Environmental Impacts:
- Bycatch of vulnerable species such as seabirds, turtles, and sharks.
- Overfishing of target and non-target species.
- Habitat disruption from anchored longlines
- “ghost fishing”: continuing to catch fish when unintended
Helped by: The use of circle hooks facilitates the safe release of accidentally caught turtles and other species.
Midwater Trawl
Cone-shaped nets used in the midwater zone to catch fish
Environmental Impacts:
- Bycatch of at-risk species like marine mammals and seabirds.
- Potential overfishing of targeted fish stocks.
- Indirect ecosystem impacts by reducing prey availability for predators
Helped by: Using streamer lines to scare away seabirds and avoiding areas with high concentrations of marine mammals
Purse Seining
Large netting used to encircle and capture schools of fish like tuna, often with fish aggregating devices (FADs).
Environmental Impacts:
- Bycatch of juvenile fish, sharks, and other vulnerable species due to FAD use.
- Overfishing of tuna and associated species.
- Ecosystem disruption from removing large quantities of fish
Helped by:
- Decreasing reliance on FADs, Using biodegradable or non-entangling FADs, Improving management practices and data collection
- Unassociated purse seines, also known as “free school” purse seines, target tuna directly without the use of FADs
Pens - Aquaculture
Structures designed to hold farmed fish in open water, constructed with materials like wood, mesh, or net screens, allowing free water flow
Environmental Impacts:
- Waste accumulation in the surrounding water, leading to nutrient pollution and algae blooms.
- Risk of escape, potentially introducing non-native or genetically modified species into wild populations.
- Spread of diseases and parasites to wild fish populations.
Types of Pens
Fixed Pens: Anchored to the seafloor in shallow waters
Net Pens: Enclosed on the bottom and sides, allowing free water flow
Submersible Net Pens: Fully enclosed and submerged, often used offshore
How to help the environmental impacts of pens?
- Regularly clean and manage waste to prevent water pollution.
- Use strong enclosures to reduce the risk of escapes.
- Monitor for disease and prevent its spread to wild populations.
Ponds - Aquaculture
Enclosures in shallow freshwater or saltwater bodies, ranging from low-tech to advanced hyper-intensive systems
Environmental Impacts:
- Historical destruction of mangrove forests for coastal pond construction.
- Pollution from untreated water discharge harming local ecosystems.
- Risk of farmed species escaping into wild habitats.
- Advanced systems with water treatment and reuse minimize these impacts
How to help the environmental impacts of ponds?
- Employ closed systems to treat and reuse water.
- Avoid constructing ponds in sensitive coastal areas.
- Implement screening systems to prevent species escape
Contour Plowing
Farming method that follows the natural topography of the land, preserving soil structure
Environmental Benefits:
- Reduces soil erosion from wind and rain.
- Maintains soil fertility and prevents runoff of nutrients into waterways
Terracing
Creating flat, stepped areas on sloped land to reduce water flow velocity
Environmental Benefits:
- Minimizes soil erosion on hillsides
- Reduces sediment runoff into rivers and streams
Windbreaks
Rows of trees or shrubs planted to block wind.
Environmental Benefits:
- Prevents wind from blowing topsoil away.
- Reduces dust storms and air pollution caused by soil particles
No-Till Agriculture
Farming method where soil is left undisturbed, and seeds are planted without tilling
Environmental Benefits:
- Decreases soil erosion and maintains soil structure
- Promotes carbon sequestration by retaining organic matter
Strip Cropping
Alternating rows of different crops to protect soil
Environmental Benefits:
- One crop holds soil in place while another is harvested
- Reduces nutrient loss and prevents soil degradation
Perennial Crops
Crops with roots that grow year-round, eliminating the need for replanting
Environmental Benefits:
- Roots hold soil together year-round, preventing erosion
- Reduces soil disturbance, promoting long-term soil health
Crop Rotation
The practice of growing different crops in succession on the same land
Environmental Benefits:
- Replenishes soil nutrients naturally (e.g., legumes fix nitrogen in the soil).
- Reduces the buildup of pests and diseases.
- Improves soil structure and fertility over time
Green Manure
Plant matter, such as cover crops, that is plowed back into the soil to decompose
Environmental Benefits:
- Adds organic bulk and NPK (Nitrogen, Phosphorus, Potassium) to the soil.
- Enhances soil structure and water retention.
- Reduces the need for synthetic fertilizers, lowering chemical runoff
Limestone
A natural mineral added to soil to adjust its pH
Environmental Benefits:
- Increases soil alkalinity, making acidic soils more neutral
- Provides essential calcium, promoting healthier plant growth.
- Helps improve nutrient availability and reduce toxic metals in the soil
Overgrazing
extensive grazing that causes damage to plants
Rotational grazing
the cycling of livestock around a particular part of their pasture as to not overgraze an area
Legislature
CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora): This international treaty aims to ensure that global trade in wildlife and plants does not threaten their survival, regulating imports and exports of endangered species through permits and quotas.
ESA (Endangered Species Act): A U.S. law that protects species at risk of extinction by designating critical habitats, prohibiting harm to listed species, and implementing recovery plans to restore their populations.
Green Revolution
A period of agricultural transformation (1940s–1970s) marked by the development of high-yield crop varieties and advanced farming techniques to address global food shortages.
- Development of high-yield crop varieties (e.g., dwarf wheat and rice).
- Introduction of synthetic fertilizers and chemical pesticides.
- Advancements in irrigation techniques.
Mechanization of agriculture (e.g., tractors, harvesters). - Significant increase in global food production.
Reduction in famine and hunger in many regions. - Transition to monoculture farming practices.
