人教高中英語必修人教高中英語必修 Using Language 第1頁/共30頁第2頁/共30頁 What do farmers usually put on the soil to make crops grow fast ? Fertilizers. 第3頁/共30頁How many kinds of fertilizers do farmers use? And what are they? There are two kinds. They are chemical fertilizers and natural ones. 第4頁/共30頁Chemical fertilizers第5頁/共30頁Natural fertilizersNatural waste from animals and dead plants第6頁/共30頁ABa product of organic farming第7頁/共30頁第8頁/共30頁第9頁/共30頁 green food organic food 第10頁/共30頁1.Do you know what is organic farming? 2.Which kind of fertilizer do farmers use when they are doing organic farming, chemical fertilizers or natural fertilizers ? Pre-reading 第11頁/共30頁Chemical Or Organic Farming?Reading第12頁/共30頁1. Scan the passage and get the main idea of parisonchemicalorganic2. Find out and underline the topicsentence of each paragraph.第13頁/共30頁Recently, however, scientists have beenfinding that long-term use of the chemical fertilizers can cause damage to the land and, even more dangerous, to peoples health.What are some of the problems causedby chemical fertilizers?Find out and underline the topic sentence of each paragraph.Para1.Para2.Skimming第14頁/共30頁P(yáng)ara 3.Para 4.With these discoveries, some farmers and many customers are beginning to turn to organic farming. Organic farmers also use many other methods to keep the soil fertile. 第15頁/共30頁Second reading ( 5ms )Read the text again and answer the following questions:1 Why are chemical fertilizers so popular in farming today?2 What problems can be caused by using chemical fertilizers ?3 What is organic farming ?4 What is the main reason for using organic farming methods ?第16頁/共30頁They can stop crop disease and increase production.第17頁/共30頁2 What problems can be caused by chemical fertilizers ?There are three problems. First, chemical fertilizers affect the soil and the water supply badly. Second, they allow farmers to grow the same crop year after year and exhaust the soil. Third, they kill both helpful and harmful pests. 第18頁/共30頁Organic farming is simply farming without using any chemicals .第19頁/共30頁4 . What is the main reason for using organic farming methods ?A healthy soil reduces disease and helps crops grow strong and healthy .第20頁/共30頁Third reading ( 8ms )Read the text again, and fill in the following forms.第21頁/共30頁What is the disadvantage of using chemical fertilizers?1.Leaving chemicals in the ground for a long time is not good for the soil or the water supply.2.Farmer often grow the same crop year after.As a result, the soil gets exhausted.3.Chemical fertilizers kill both helpful and harmful bacteria and pests.第22頁/共30頁Methods of organic farmingAdvantages of methods1 Farmers use natural waste from animals.1 This makes the soil richer in minerals and so more fertile.2 Farmers often change the kind of crop in each field every few years.2 Changing the crops renews the minerals in the soil and helps it become rich and healthy.第23頁/共30頁Methods of organic farmingAdvantages of methods3 Farmers plant crops with different lengths of roots.3 This uses different levels of soil.4 Farmers sometimes plant grass between crops and leave it in the ground.4 This prevents wind or water from carrying away soil and acts as a natural fertilizer.第24頁/共30頁In what condition do you think green food grow?dirty air dirty water supplies in industrial areas many chemical fertilizersclean, freshcleanaway fromfree of第25頁/共30頁 In recent days, scientists _(discover) that using chemical fertilizers for a long time can be _(harm) to the land and also to peoples health. There are several problems _(cause) by chemical fertilizers. They damage the land and stay in the water for a long time, _ can build up in peoples bodies and lead to many _(ill). Therefore, organic farming is becoming _ (popular) with some farmers. They dont use any chemicals and focus on _(keep) the soil rich. This also keeps the air and crops free_chemicals. There are many other methods to make the land healthy and productive. All of these methods have _ same goal: to grow good food and avoid _(damage) the environment or our health.have discoveredharmfulcausedwhichillnessesmore popularkeepingfrom/ofthedamaging第26頁/共30頁*Problems caused by chemical fertilizers*What is organic farming? *What fertilizer should they use? Why? .第27頁/共30頁第28頁/共30頁第29頁/共30頁感謝您的觀看！第30頁/共30頁