1、Unit 2 Chemical or Organic Farming?Unit 2 Chemical or Organic Farming?What do farmers need to grow food?They need+Chemical fertilizersNatural fertilizers_ farming_ farmingchemicalorganicChemical or Organic Farming?Predict what we will know from the passage. Well know. Chemical or Organic Farming?Tas
2、k 1 Underline the topic sentence of each paragraph.A What are some of the problems caused by chemical fertilizers? First, they damage the land by killing the helpful bacteria and pests as well as the harmful ones. Chemicals also stay in the ground and underground water for a long time. This affects
3、crops and, therefore, animals and humans, since chemicals get inside the crops and cannot just be washed off. These chemicals in the food supply build up in peoples bodies over time. Many of these chemicals can lead to cancer or other illnesses. In addition, fruit, vegetables and other food grown wi
4、th chemical fertilizers usually grow too fast to be full of much nutrition. They may look beautiful, but inside there is usually more water than vitamins and minerals. Task 1 Underline the topic sentence of each paragraph.A. What are some of the problems caused by chemical fertilizers?B. ._C. ._D. .
5、_Task 1 Underline the topic sentence of each paragraph.B With these discoveries, some farmers and many customers are beginning to turn to organic farming. Organic farming is simply farming without using any chemicals. They focus on keeping their soil rich and free of disease. A healthy soil reduces
6、disease and helps crops grow strong and healthy. Organic farmers, therefore, often prefer using natural waste from animals as fertilizer. They feel that this makes the soil in their fields richer in minerals and so more fertile. This also keeps the air, soil, water and crops free from chemicals. Tas
7、k 1 Underline the topic sentence of each paragraph.C Organic farming also use many other methods to keep the soil fertile. They often change the kind of crop in each field every few years, for example, growing corn or wheat and then the next year peas or soybeans. Crops such as peas or soybeans put
8、important minerals back into the soil, making it ready for crops such as wheat or corn that need rich and fertile soil. Organic farmers also plant crops to use different levels of soil, for example, planting peanuts that use the grounds surface followed by vegetables that put down deep roots. Some o
9、rganic farmers prefer planting grass between crops to prevent wind or water from carrying away the soil, and then leaving it in the ground to become a natural fertilizer for the next years crop. These many different organic farming methods have the same goal: to grow good food and avoid damaging the
10、 environment or peoples health. Task 1 Underline the topic sentence of each paragraph.D Over the past half century, using chemical fertilizers has become very common in farming. Many farmers welcomed them as a great way to stop crop disease and increase production. Recently, however, scientists have
11、 been finding that long-term use of these fertilizers can cause damage to the land and, even more dangerous, to peoples health. The topic sentences of each paragraph:A. What are some of the problems caused by chemical fertilizers?B. With these discoveries, some farmers and many customers are beginni
12、ng to turn to organic farming.C. Organic farmers also use many other methods to keep the soil fertile.D. Recently, however, scientists have been finding that long-term use of these fertilizers can cause damage to the land and even more dangerous, to peoples health.Task 2 Put the four paragraphs in o
13、rder. ABCD_ _ _ _ The topic sentences of each paragraph:A. What are some of the problems caused by chemical fertilizers?B. With these discoveries, some farmers and many customers are beginning to turn to organic farming.C. Organic farmers also use many other methods to keep the soil fertile.D. Recen
14、tly, however, scientists have been finding that long-term use of these fertilizers can cause damage to the land and even more dangerous, to peoples health.Task 2 Put the four paragraphs in order. ABCD_ _ _ _ Task 2 Find the structure of the passage1.Whats the function(功能功能) of the first paragraph? A
15、. to explain the topic B. to analyse the topic C. to introduce the topic2. Which two paragraphs can be grouped together?Para 2 problems Para 3 organic farming Para 4 organic farming methods3. Whats the relationship between Paragraph 2 and Paragraph 3&4?Para 2 Chemical farming causes the problems.Par
16、a 3&4 Organic farming _ the problems.solvesPara 1 Topic Why are chemical fertilizers so popular in farming? .a great way to stop crop disease and increase production.Para 2 Problems How many problems are listed in this paragraph?1.2.3.Problems caused by chemical fertilizersFirstAlsoIn additionDamage
17、 _Watercropsanimals, humans the landFruit, vegetables, other foodPara 3&4 SolutionTask 1 What do organic farmers focus on ? They focus on keeping their soil rich and free of disease.Para 3&4 SolutionTask 2 Underline the organic farming methods and their advantages in Para 3&4.Task 3 Retell the organ
18、ic farming methods with the help of the key information on the blackboard and picturesOrganic farmers prefer using _ as _.natural wastefertilizerdifferent levels of soilsurfaceundergroundsoilOrganic farmers plant crops to use_.Some crops use the _of soil, followed by other crops that put down _.surf
19、acedeep rootscropsgrasssoilplant. between.prevent. from.become a natural. change .put . back into .make it ready for.1. Whats the writers answer to the question Chemical or organic farming?2. If you were a farmer, which one is more important to you? Wealth or Health? Work in groups.Suppose(假设假设) you
20、 have a farm, you need to design the farm. (1) Use at least TWO organic farming methods learned from the passage. (2) Draw a picture of your farm (You can write something on the picture if needed).(3) Introduce your farm to the class. (Method? Advantages?)1. Summary What have we learned today?readingfarming; structure; thinking; expressing 2. Homework: Improve your design of the farm. Look for more information about organic and chemical farming.
