Env Sci Chapter 17

cover crop

A crop planted in the off-season to help prevent soil erosion and to return nutrients to the soil. (Chapter 17)

biochar

A form of charcoal, produced when organic matter is partially burned, that can be used to improve soil quality. (Chapter 17)

strip cropping

Alternating different crops in adjacent strips, several rows wide; helps keep pest populations low. (Chapter 17)

What information would you like to see on food labels that would allow you to make wise consumer choices when buying food? Does food labeling need to be regulated so that certain terms (e.g., organic, free range) is specifically defined?

Answers will vary but might include things like country or even state of origin, method of growing (organic, sustainable, industrial, etc.); date it was processed or picked; expiration date, carbon footprint to produce, etc. Regulation of labels makes it easier for consumers to really know what they are getting. Unregulated terminology is meaningless and can be used to confuse or sway the consumer (greenwashing).

How could application of a pesticide actually lead to an increase the size of the pest population? (Hint: Think about the predators of the pests.)

Application of a pesticide might increase the size of the pest population by killing the predators that eat the pests. If the pest population rebounds faster than the predator populations, the pest population size could grow larger, having lost the natural population control provided by its predator.

Organic farming is a subset of sustainable farming. What do these farming methods have in common, and how do they differ?

Both methods have as an underlying goal to farm without damaging the environment. Organic farming is more restrictive in that it prohibits the use of synthetic fertilizers and pesticides, and GMOs.

greenwashing

Claiming environmental benefits about a product when the benefits are actually minor or nonexistent. (Chapter 17)

concept 17.8

Consumers can support sustainable agriculture with their purchases. Buying locally grown, organic food is the best option for reducing the carbon footprint of that food.

Which of these sustainable soil practices help reduce soil erosion, which help improve soil fertility, and which help reduce pest outbreaks?

Contour farming, terrace farming, reduced tillage, and cover drops all reduce soil erosion; Crop rotation, strip cropping and cover crops improve soil fertility; Crop rotation and strip cropping help reduce pest outbreaks.

perennial crop

Crops that do not die at the end of the growing season but live for several years, allowing them to be harvested annually without replanting. (Chapter 17)

annual crops

Crops that grow, produce seeds, and die in a year and must be replanted each season. (Chapter 17)

polyculture

Farming method in which a mix of different species are grown together in one area. (Chapter 17)

monoculture

Farming method in which a single variety of one crop is planted, typically in rows over huge swaths of land, with large inputs of fertilizer, pesticides, and water. (Chapter 17, 32)

sustainable agriculture

Farming methods that can be used indefinitely because they do not deplete resources, such as soil and water, faster than they are replaced. (Chapter 17)

industrial agriculture

Farming methods that rely on technology, synthetic chemical inputs, and economies of scale to increase productivity and profits. (Chapter 16, 17)

contour farming

Farming on hilly land in rows that are planted along the slope, following the lay of the land, rather than oriented downhill. (Chapter 17)

organic agriculture

Farming that does not use synthetic fertilizers, pesticides, or other chemical additives like hormones (for animal rearing). (Chapter 17)

concept 17.3

Fertilizer use can increase productivity but can degrade soil and contaminate nearby bodies of water.

pesticides

A natural or synthetic chemical that kills or repels plant or animal pests. (Chapter 17)

fertilizers

A natural or synthetic mixture that contains nutrients that is added to soil to boost plant growth. (Chapter 16, 17)

concentrated animal feeding operation (CAFO)

A situation in which meat or dairy animals are raised in confined spaces, maximizing the number of animals that can be reared in a small area.

concept 17.2

Industrial agriculture is very productive but relies on large amounts of fossil fuels and water, degrades the soil and local environment (reducing future productivity), and is criticized for treating animals unethically.

concept 17.6

Integrated pest management techniques can often effectively control pests while minimizing or eliminating the use of chemical pesticides.

concept 17.5

Modeling a farm after an ecosystem (agroecology) to include a variety of plants and animals can boost productivity and protect or even enhance the local environment.

What normal industrial inputs can be averted by growing rice using the duck/rice farm model?

No synthetic fertilizers are needed since ducks, fish, and azolla all provide nutrients. Pesticides are not needed since ducks and fish eat insect pests and weeds.

cultural eutrophication

Nutrient enrichment of an aquatic ecosystem that stimulates excess plant growth and disrupts normal energy uptake and matter cycles. (Chapter 15, 17)

terracing

On steep slopes, land is leveled into steps; reduces soil erosion and runoff down the hillside. (Chapter 17)

concept 17.4

Pesticide use can help fight pests but is toxic to other species, including humans, and can lead to pesticide resistant pest populations.

seed banks

Places where seeds are stored in order to protect the genetic diversity of the world's crops. (Chapter 17)

reduced-tillage cultivation

Planting crops in soil that is minimally disturbed and that retains some plant residue from the previous planting. (Chapter 17)

crop rotation

Planting different crops on a given plot of land every few years to maintain soil fertility and reduce pest outbreaks. (Chapter 17)

agroecology

Scientific field that considers the area's ecology and indigenous knowledge, and favors agricultural methods that protect the environment and meet the needs of local people. (Chapter 17)

concept 17.9

Sustainable agriculture comes with trade-offs, but many feel that the disadvantages are less problematic than are those of modern industrial agriculture, especially in the long term.

concept 17.7

Sustainable agriculture draws on a variety of traditional farming methods that can protect or improve soil and reduce pest problems. Many of these methods can be used on large and small scales.

pesticide resitance

The ability of a pest to withstand exposure to a given pesticide, the result of natural selection favoring the survivors of an original population that was exposed to the pesticide. (Chapter 17)

carbon footprint

The amount of carbon dioxide (CO2) or other greenhouse gas released by an action; a concern because it contributes to climate change.

How could the disadvantages of fertilizer use be managed to reduce their impact?

The application of less fertilizer would reduce the amount available to runoff and enter water sources. Microfertilization, such as that used in Burkina Faso (see Chapter 16) applies only enough fertilizer (right at the base of the plant) that the plant can use so there is none left over. Planting vegetative buffers around fields and nearby bodies of water would also reduce runoff reaching those bodies of water. Reducing dependence on fertilizer could be addressed by limiting fertilizer use or taking other steps to enrich soil (such as planting crops that add nutrients, rotating crops so different levels of nutrients are pulled out of the soil from year to year, and allowing the soil to lay fallow for a year every so often. [These latter topics are covered later in the chapter but this question provides good food for thought.]

food miles

The distance a food travels from its site of production to the consumer. (Chapter 17)

concept 17.1

The goal of sustainable agriculture is to raise food without damaging the environment or future productivity while operating ethically with regard to animals and local communities.

integrated pest management (IPM)

The use of a variety of methods to control a pest population, with the goal of minimizing or eliminating the use of chemical toxins. (Chapter 17)

What pest control methods did the Massas use in their rice fields? Identify each as cultural, biological, mechanical, or chemical.

They used mechanical (changing the water level in the rice fields to control azolla growth) and biological (ducks and fish to eat azolla and other pests).