<P> This was one of the main procedures promoted by the UK Soil Conservation Service (the current Natural Resources Conservation Service) during the 1930s . The US Department of Agriculture established the Soil Conservation Service in 1935 during the Dust Bowl when it became apparent that soil erosion was a huge problem along with desertification . </P> <P> The extent of the problem was such that the 1934 "Yearbook of Agriculture" noted that Approximately 35 million acres (142,000 km2) of formerly cultivated land have essentially been destroyed for crop production...100 million acres (405,000 km2) now in crops have lost all or most of the topsoil; 125 million acres (506,000 km2) of land now in crops are rapidly losing topsoil . This can lead to large scale desertification which can permanently transform a formerly productive landscape to an arid one that becomes increasingly intensive and expensive to farm . </P> <P> The Soil Conservation Service worked with state governments and universities with established agriculture programs such as the University of Nebraska to promote the method to farmers . By 1938, the introduction of new agricultural techniques such as contour plowing had reduced the loss of soil by 65% despite the continuation of the drought . </P> <P> Demonstrations showed that contour farming, under ideal conditions, will increase yields of row crops by up to 50%, with increases of between 5 and 10% being common . Importantly, the technique also significantly reduces soil erosion, fertilizer loss, and overall makes farming less energy and resource intensive under most circumstances . Reducing fertilizer loss not only saves the farmer time and money, but it also decreases risk of harming regional freshwater systems . Soil erosion caused from heavy rain can encourage the development of rills and gullies which carry excess nutrients into freshwater systems through the process of eutrophication </P>

Where would contour farming and terraces be most likely to be found