Test #3- topics

(7) Traditional agriculture-

"work of cultivating, harvesting, storing, and distributing crops was performed by human and animal muscle power" (no complex machinery)

(7) Define a "sustainable" rate of soil loss. Describe how you might determine whether a given farm was practicing sustainable use of soil.

A sustainable rate of soil loss would mean that the the rate of soil loss is not higher than the local rate of soil formation. By measuring the amount of topsoil at a given farm, you would be able to see if the farm practices are sustainable.

(7) How does terracing effectively turn steep and mountainous areas into arable land? Explain the method of no-till farming. Why does this method reduce soil erosion?

A terrace farm is perfect for a rocky terrain. It creates level platforms out of the mountain or hillsides that "contain water from irrigation and precipitation." Because of its unique set- up, the terrace farms "enable farmers to cultivate hilly land without losing huge amounts of soil to water erosion."

(7) Why is erosion generally considered a destructive process?

Erosion removes materials and transports them to another location. It often occurs at a faster rate than the soil develops. In addition, it removes top soil, which is extremely rich in nutrients and important for organisms. Because of erosion, fertility can decrease.

(7) How do fertilizers boost crop growth? How can large amounts of fertilizer added to soil also end up in water supplies and the atmosphere?

Fertilizers "enhance nutrient-limited soil", making them healthier and better for the growth of crops. Fertilizers are not perfect. The chemicals in fertilizers can mix with water that run offs into different water supplies. The chemical filled water also evaporates into the atmosphere, adding dangerous chemicals into the air we breath.

Are forest fires a bad thing? Explain your answer.

For the most part, forest fires are a natural occurrence. Although they cause obvious destruction of habitat and an emission of gases, the fires also help to remove litter and assist in seed germination. As a natural system, they are not "bad" because they do have various benefits.

What is recombinant DNA? How is a transgenic organism created?

Recombinant DNA is a form of DNA that has been artificially constructed to join different organism's DNA together A transgenic organism is created when a part of DNA from one species is combined with the DNA of another

(7) How are soil horizons created?

Small particles of soil are sorted by wind, water and organisms to create different levels.

(7) industrialized vs traditional agriculture

The "large-scale mechanization and fossil fuel combustion to agriculture" replaced the traditional farming methods in the industrial revolution. Industrial- high(er) tech, traditional (simple/no tech)

How do minerals differ from tiber when it comes to resource management?

The amount of minerals are finite in amount. More timber is infinite, meaning that more can always be regrown. Because timber has great growth potential, it is a better choice for production or other means as a renewable resource.

(7) How do you think a farmer can best help to conserve soil?

farmers- reduce or eliminate till farming, reduce the use of inorganic fertilizers (or eliminate), or use the process of terrace farming to grow crops.

Explain how pesticide resistance occurs.

natural selection. After pesticide application, resistant organisms survive and reproduce at higher rates (more access to resources). As a result, the population of the species eventually develops a strong resistance over time.

What are some of economic benefits of aquaculture? What are some negative environmental impacts?

positive-ensures reliable protein source on one's diet, provides products than can be sued for crop fertilizer (lowers the requirement for purchased fertilizer). negative- increased risk of disease or infection, decreases the energy efficiency of food production.

(7) subsistence vs intensive agriculture

subsistence farmers only produce enough food for their families while intensive farmers produced extra food to sell.

(7) What processes are most responsible for the formation of soil? Describe the three types of weathering that may contribute to soil formation.

the process of weathering contributes the the formation of soil by breaking down "rocks and minerals [and turning] the large particles into smaller particles" Physical Weathering- physical conditions. breaks down without chemical process, daily and seasonal changes can instigate changes Chemical Weathering when "water or other substances react with parent material" ("base geological material"- larger rocks/ minerals) Biological Weathering- (tree roots and lichens)- "living things break down parent material"- organisms spark change

What kinds of techniques have people employed to increase agricultural food production?

using fossil fuel energy toward food production, planting and harvesting more often, increasing the use of irrigation fertilization and pesticides, and using GMOs to produce crops at a faster rate.