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.