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
Tianji Coal Chemical Industry Group chemical spill Tianji Coal Chemical Industry Group chemical spill The Tianji Coal Chemical Industry Group chemical spill was a severe chemical spill that occurred in Shanxi Province, China during 2012–2013. More than 39 tons of anilines (toxic chemicals widely used as precursors in the manufacture of pigment, herbicides and other chemicals) leaked from a loose drainage valve at a plant owned by Tianji Coal Chemical Industry Group in the Shanxi city of Changzhi. This chemical spill contaminated the Zhuozhang River which is the source of drinking water for more than one million people, and so caused a water crisis in the downstream