Appendix (for reading content...etc)
Read the passage 'The plow'. On a piece of paper, take notes on the main points of the reading passage.
Reading time: 3 minutes
The plow
The plow is one of our greatest inventions because it makes large-scale agriculture possible. The practice of turning the soil before planting is very old, but until the plow was invented, farming was limited to what humans could do by hand. The plow has enabled us to cultivate larger and larger areas of land, and in places where farming was previously impossible. Advances in plowing technology have made it possible to convert native grasslands into huge fields of corn and wheat.
Tilling the soil with a plow improves the soil in numerous ways. The plow turns over the upper layer of soil, bringing fresh nutrients to the surface. This also loosens and aerates the soil, improving its ability to hold moisture and nutrients. Freshly turned soil is darker in color, which enhances soil warming and thereby promotes seed germination. Turning the soil buries crop residues—the stalks, leaves, and roots remaining from the previous year's harvest-allowing them to break down more quickly. Plowing incorporates these residues into the soil, along with any manure, limestone, and commercial fertilizers that are applied. In addition, plowing creates a pattern of low and high ridges in the soil, forming water channels that allow the soil to drain properly.
The plow reduces the costs and labor requirements of agriculture. With the introduction of animal-drawn plows, fewer people were needed to till the same amount of land. In time, mechanized plowing further reduced labor requirements, permitting the labor of a few people to sustain many. The plow greatly reduced the amount of time needed to prepare a field, consequently allowing a farmer to work a larger area of land. This, in turn increased each farmer’s crop yields.
Main idea of the reading passage:
Major points in the reading passage:
Now listen to the passage. On a piece of paper, take notes on the main points of the listening passage.
[audio|src:'\listening\toefl_begin\CD6-25.mp3?20210617'|wait:185]
The plow is responsible for larger crop yields, but there are also some problems with it. For one thing, simply producing large amounts of food is not enough. Food has to be produced in a sustainable way so natural resources are conserved for future generations. No-till agriculture—farming without the plow—has the potential to help develop a more sustainable agriculture.
Another problem is that overuse of the plow is a major cause of damage to the land. Plowing leaves the soil vulnerable to erosion by wind and water. An example is the Dust Bowl disaster, when extensive plowing, combined with long periods of no rain, caused the dry topsoil to be blown away in dust storms. Plowing also increases erosion by water, and the channels in fields promote the runoff of soil and fertilizers into lakes, rivers, and oceans.
In contrast, no-till farming minimizes soil damage. Instead of plowing under the remains of last year's crop-stalks and other litter—farmers leave it on the fields, where it acts as mulch to conserve water and protect the soil from erosion. Leaving crop residue in place increases levels of organic matter and improves soil productivity. Finally, overuse of the plow is a threat to rural livelihoods, particularly in the developing world. No-till farming has economic advantages. For example, the number of passes over a field needed to grow and harvest a crop decreases from seven or more to about four, thereby saving fuel and labor costs. In fact, no-till farming uses 50 percent less fuel, and 30 to 50 percent less labor than plow-based farming. This means a significantly lower production cost per acre.
Main idea of the listening passage:
Major points in the listening passage:
- Producing large amounts of food is not enough; food production must be sustainable.
- Overuse of the plow is a major cause of soil damage; no-till farming minimizes soil damage
- Overuse of the plow is a threat; no-till farming has economic advantages.
Now answer the following question:
Summarize the points made in the lecture, being sure to explain how they challenge specific points made in the reading passage.
Sample Answer:
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