chemical-or-organic-farmingPPT優(yōu)秀課件

1、Working the Land1Plough Agricultural activitiesSeed Fertilize Irrigate Harvest 2Plough (犁田）犁田） Agricultural activitiesSeed（播種（播種） Fertilize（施肥）（施肥） Irrigate（灌溉）（灌溉） Harvest收獲收獲 3The The processprocess（過(guò)過(guò)程）程） of farmingof farming Step 1 buy seeds from the store. Step 2 plough or turn over the soil. S

2、tep 3 sow（播撒）（播撒） the seeds in the soil . Step 4 harvest our crops.Working the Land4 In order to In order to keep crops grow keep crops grow strong and healthy, farmers willstrong and healthy, farmers will 1 rid the soil of weeds(雜雜草）草）. 2 kill the pests. 3 irrigate（灌（灌溉溉） the crops. 4 put fertilize

3、rs in the soil (make the soil fertile)5In order to increase the In order to increase the outputoutput of crops, of crops, farmers will use? farmers will use? fertilizerschemical fertilizers natural fertilizers 化肥化肥 天然肥料天然肥料6chemical fertilizers natural fertilizers chemical farming 化學(xué)耕種化學(xué)耕種 organic f

4、ertilizers 有機(jī)耕種有機(jī)耕種 Better?7Chemical or Organic Farming?8Skimming What is organic farming?What is chemical farming?Chemical farming is farming by using _ .Organic farming is simply farming without any chemicals.It uses natural fertilizers instead.Para1-2Para3-4chemical fertilizers9 disadvantages1. d

5、amage the land2. affect crops, animals & humans3. make fruit, vegetables and other food have less nutrition advantagesstop crop disease & increase productionFirst,Also,In addition,Para1-2careful ReadingOver the past half century, using chemical fertilizers has become very common. 10With this discove

6、ries, some farmers and many customers are beginning to turn to organic farming.methods1. using natural waste from animals as fertilizer2. changing the kind of crop in each field every few years 3. planting different crops to use different levels of soil4. planting grass between crops & leaving it in

7、 the groundgoal to grow good food and to avoid damaging the environment or peoples health.Para3-411chemical fertilizers natural fertilizers chemical farming 化學(xué)耕種化學(xué)耕種 organic farming 有機(jī)耕種有機(jī)耕種 Better?organic farming 12Now , lets try to write a summary for the passage.Step1: find out the topic sentence

8、 and key information in each paragraph.Step2: rewrite the sentences in your own words.Step3: use conjunctions（連詞）to put all the information together.13Para1Over the past half century, using chemical fertilizers has become very common in farming. Many farmers welcomed them as a great way to stop crop

9、 disease and increase production. 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.Tip1. find out the topic sentence(找主題句）找主題句）topic sentence14Para1Over the past half century, using chemic

10、al 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 been finding that long-term use of these fertilizers can cause damage to the land and, even more dangerous, to peoples health.T

11、ip1. find out the topic sentence(找主題句）找主題句）topic sentenceRewrite the topic sentence: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.15Para1Over the past half century, using chemical ferti

12、lizers 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 been finding that long-term use of these fertilizers can cause damage to the land and, even more dangerous, to peoples health.In recent

13、 days, scientists have discovered that using chemical fertilizers for a long time can hurt the land and also (even) peoples health.Tip2. （替換詞）（替換詞）discover;use.for a long time; be harmful to / do harm to / hurtnowadays/in recent days;16 Para2 What are some of the problems caused by chemical fertiliz

14、ers? 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 crops and, therefore, animals and humans, since chemicals get inside the crops and cannot just be washed off.

15、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 with chemical fertilizers usually grow too fast to be full of much nutrition. They may look beautiful, but insid

16、e there is usually more water than vitamins and minerals. topic sentence17There are several problems caused by chemical fertilizers. Para2 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.

17、Chemicals also stay in the ground and underground water for a long time. This affects 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 lea

18、d to cancer or other illnesses. In addition, fruit, vegetables and other food grown with 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. detailsTip2: （疑問(wèn)句變成陳述句（疑問(wèn)句變成陳述句/主動(dòng)句變被動(dòng)句）主動(dòng)句變被動(dòng)

19、句）,for example / such as/ like.topic sentence18Para3 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 dise

20、ase 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 fortile. This also keeps the air, soil, water and crops free from chemicals. Organic

21、 farming is becoming more popular with some farmers and many customers beacause of this discoveries.Tip3: change the subject（換主語(yǔ)）（換主語(yǔ)）Organic farming which uses natural fertilizers is becoming more popular with some farmers and many customers because of these discoveries.topic sentence19Para3 With t

22、hese 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 disease and helps crops grow strong and healthy. Organic farmer

23、s, 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 fortile. This also keeps the air, soil, water and crops free from chemicals. Organic farming is becoming more popular with some farmers and man

24、y customers beacause of this discoveries.Tip3: change the subject（換主語(yǔ)）（換主語(yǔ)）Organic farming which uses natural fertilizers is becoming more popular with some farmers and many customers because of this discoveries.20Para4 Organic farmers also use many other methods to keep the soil fertile.They often.

25、Organic farmers also plant.Some organic farmers prefer.These many different organic farming methods have the same goal: to grow good food and to avoid damaging the environment or peoples health.Some other measures have been taken to produce good food and to keep the environment and people healthy. T

26、ip4: change the active voice into passive voice2122Skimming Find and underline the topic sentence. Retelling them in your own words23 Scientists have recently discovered that using chemical fertilizers for a long time can do harm to the land and also peoples health.P1.P2.Problems caused by chemical

27、fertilizers.Organic farming is becoming more and more popular with Farmers and customers after discoveries came out. P3.P4.Other methods to keep the soil fertile. 24Summary Scientists have recently discovered several Scientists have recently discovered several serious problems caused by chemical ser

28、ious problems caused by chemical fertilizers, while organic farming, which can fertilizers, while organic farming, which can make the land healthy and productive, is make the land healthy and productive, is becoming more and more popularbecoming more and more popular25Reading carefully Read Para 1 a

29、nd answer: 1 Why are chemical fertilizers so popular in farming today? 2 After the long-term use of chemical fertilizers, what have scientists discovered?26 Many farmers welcomed them as a great way to stop disease and increase production.1 Why are chemical fertilizers so popular in farming today?27

30、2 After the long-term use of chemical fertilizers, what have scientists discovered? Recently, Recently, howeverhowever, long-term use of , long-term use of chemical fertilizers can chemical fertilizers can cause damage tocause damage to the the land and ,land and ,even more dangerouseven more danger

31、ous, to peoples , to peoples health.health. Some adverbs are often used in writing, Some adverbs are often used in writing, such assuch as nevertheless, therefore, meanwhile, nevertheless, therefore, meanwhile, anyhow, otherwise, moreover, besides, in anyhow, otherwise, moreover, besides, in additio

32、n, thus, and so on.addition, thus, and so on.28Read Para 2 and find out the problems caused by using chemical fertilizersThere are mainly three reasons. There are mainly three reasons. First,First, they can they can d damage amage the land bythe land by killing the killing the helpful helpful bacter

33、ia and pests bacteria and pests as well as well asas the the harmfulharmful ones. Chemicals ones. Chemicals alsoalso stay in the ground stay in the ground and underground water for a long time. and underground water for a long time. This affectsThis affects crops and crops and thereforetherefore, an

34、imals, , animals, sincesince.build upbuild up lead lead toto In addition,.In addition,.They may look beautiful,They may look beautiful, but but inside .inside . 29列舉理由的常見表達(dá) first, second, thirdfinally firstly, secondly, thirdlyfinally first of all, next ，then, lastly for one thingfor another at the

35、same time 30Read Para 3 and answer: What are the advantages of organic farming?31 They focus on keeping their soil rich and free from disease.reduces disease and . helps crops grow strong and healthy.makesricher and more fertile also keeps . free from32Read para 4 and answer: What methods do organic farmers use to keep the soil fertile? 1. Using natural waste from animals as fertilizers 332. Changing the kind of crop in each field every few years.3 . Planting crops to use different levels of soil.4. Planting grass between crops to prevent wi