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
Smother crop thus providing green fertilizer. A good smother crop must compete strongly with weeds but minimally with the crop. Smother crops reduce dependence on chemical weed control. Some secondary benefits of such crops are helping nitrogen fixation in soil (if legumes are used) and reducing soil erosion. Alfalfa, rye, buckwheat, sorghum, Sudan grass, foxtail millet, sweetclover, clover and silage corn are some examples of smother crops. Smother crop A smother crop is a thick, rapidly growing crop that is used to suppress or stop the growth of weeds. Smother crops have better root systems that help them compete with weeds for