In geology, the unsorted material deposited directly by glacial ice and showing no stratification. Till is sometimes called boulder clay because it is composed of clay, boulders of intermediate size, or both. The rock fragments are usually angular and sharp rather than rounded, because they are deposited from ice and have undergone little water transport. The pebbles and boulders may be faceted and striated from grinding while lodged in the glacier.
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Cultivation technique in which the soil is disturbed only along the slit or hole into which seeds are planted. Reserved detritus from previous crops covers and protects the seedbed. Primary benefits are a decreased rate of soil erosion; reduced need for equipment, fuel, and fertilizer; and significantly less time required for tending crops. The method also improves soil-aggregate formation, microbial activity in the soil, and water infiltration and storage. Conventional tillage controls weed growth by plowing and cultivating, but no-till farming selectively uses herbicides to kill weeds and the remains of the previous crop. No-till farming is one of several primitive farming methods revived as conservation measures in the 20th century.
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German peasant trickster of folk and literary tales. The historical Till is said to have died in 1350; anecdotes associated with his name were printed circa 1500 in Low German and from 1515 in High German. In the tales the stupid yet cunning peasant demonstrates his superiority to the narrow, dishonest, condescending townsmen, as well as to the clergy and nobility. The tales were translated into Dutch and English (circa 1520), French (1532), and Latin (1558).
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Deposit of sand and gravel carried by running water from the melting ice of a glacier and laid down in stratified deposits. An outwash may be as much as 330 ft (100 m) thick at the edge of a glacier, and it may extend for many miles. Outwashes are the largest glacial deposits and provide a considerable source of windblown material.
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Most important carboxylic acid (CH3COOH). Pure (“glacial”) acetic acid is a clear, syrupy, corrosive liquid that mixes readily with water. Vinegar is its dilute solution, from fermentation and oxidation (see oxidation-reduction) of natural products. Its salts and esters are acetates. It occurs naturally as a metabolic intermediate in body fluids and plant juices. Industrial production is either synthetic, from acetylene, or biological, from ethanol. Industrial chemicals made from it are used in printing and as plastics, photographic films, textiles, and solvents.
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