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
Safe Drinking Water Act maintaining the bacteriological quality of drinking water. The Safe Drinking Water Act was one of several pieces of environmental legislation in the 1970s. Discovery of organic contamination in public drinking water and the lack of enforceable, national standards persuaded Congress to take action. Historically, up through 1914, drinking water quality in the United States was managed at the state and local level. After that, interstate waters were protected using United States Public Health Service (USPHS) standards. Ultimately the USPHS standards were adopted and expanded as national drinking water standards after passage of the 1974 law. The 1974 law very clearly