Crop rotation British Agricultural Revolution. The rotation between arable and ley is sometimes called ley farming. George Washington Carver (1860s–1943) studied crop-rotation methods in the United States, teaching southern farmers to rotate soil-depleting crops like cotton with soil-enriching crops like peanuts and peas. In the Green Revolution of the mid-20th century the traditional practice of crop rotation gave way in some parts of the world to the practice of supplementing the chemical inputs to the soil through topdressing with fertilizers, adding (for example) ammonium nitrate or urea and restoring soil pH with lime. Such practices aimed to increase yields, to prepare soil
Drinking water from 40 to 80 percent. Nearly 4.2 billion had access to tap water while another 2.4 billion had access to wells or public taps. Estimates suggest that at least 25% of improved sources contain fecal contamination. 1.8 billion people still use an unsafe drinking water source which may be contaminated by feces. This can result in infectious diseases, such as gastroenteritis, cholera, and typhoid, among others. Reduction of waterborne diseases and development of safe water resources is a major public health goal in developing countries. Bottled water is sold for public consumption in most parts of the world. One of