2014-2015高中英语 ORGANIC FARMING素材 新人教版必修4

2014-2015 高中英语 ORGANIC FARMING 素材 新人教版必修 4Agricultural scientists in Switzerland have demonstrated the long-term effects of organic farming methods. Organic farms use no man-made chemicals to increase crops or control insects and disease. The study showed that organic fields produced fewer crops, on average, than other fields. However, the scientists say the organic methods improved the health of the soil and used half as much energy. Graphic ImageScientists at the Research Institute of Organic Agriculture in Frick, Switzerland, supervised the study. They reported their findings in Science magazine, the publication of the American Association for the Advancement of Science.It was one of the longest-running studies of its kind. The Swiss scientists compared the effects of organic and traditional farming methods over a period of more than twenty years. They grew crops on four fields of land in Switzerland.Two fields were grown using traditional farming methods. The others were grown using organic farming methods. The scientists grew potatoes, barley, winter wheat, beets and grass clover. The crops, planting methods, and soil use were similar in all the fields studied.The study found that the organic fields produced about twenty percent fewer crops than the other fields. However, the farmers used less fertilizer and energy on the organic fields. They found the organic fields were healthier.The scientists say the organic fields had more nutrients in the soil. The soils in the organic fields also had more biological activity than the other fields. The organic fields had more helpful organisms and a larger number of different organisms. The organic fields had almost two times as many insects, including helpful insects. In traditional farming, chemicals designed to kill harmful insects also can kill helpful ones.The researchers say the findings show that organic crop production rates change little over time, and that soil fertility increases. They say the findings suggest that organic farmers can help the environment by increasing soil fertility.Organic farming is becoming increasingly popular in some countries. Many people believe that eating organic food is more healthful than eating food grown with chemicals. Some people are willing to pay more money to buy organic food.