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Show 74.888 A raindrop splash. IND- 20,462 Rye seeded in corn in the fall as a cover crop protects soil from erosion during winter and spring. a height of more than 2 feet and may be moved more than 5 feet horizontally on level surfaces. On steep slopes soil particles fall downhill and therefore result in considerable soil movement without being carried by water. Fine soil particles are the most easily moved. This results in erosion of the fine particles such as silt and clay, leaving only sand and gravel on the surface. You can see this in cultivated fields after hard rains. Any kind of crop cover cuts down soil movement. A hayfield would not lose as much soil as a cornfield, especially where the corn is small. Slope is expressed in percent, meaning the number of units the land falls ( or rises) in 100 units of horizontal distance. You can measure how steep a slope is with some simple materials. You will need a yardstick, a straight stick exactly 50 inches long, and a carpenter's level or a flat bottle half full of a colored liquid. Go out on the schoolyard or to any place you would like to know how steep the slope is. Place the 50- inch stick horizontally on the ground ( one end will be higher than the other because of the slope), as 21,399 A dense stand of wheat or other close- growing vegetation breaks the force of raindrops, allowing them to fall gently to the ground. After the corn gets large enough to cover the ground between the rows, the leaves will break the impact of falling rain, and any erosion that follows will be caused by the movement of water on the surface breaking loose the particles, not by raindrop splash. Also, soil erosion will be more severe on cultivated fields during early spring when che ground is bare before the crop gets started and where spring rains are heavy. In the South where the ground does not freeze during the winter when rain is normally heavy, cover crops reduce splash erosion. shown in the drawing. Put the level ( or the bottle) on the 50- inch stick, and move the free end of the stick up or down until the bubble ( or the water) shows that the stick is level. Read on the yardstick the distance from the ground to the bottom edge of the horizontal stick. This reading in inches, multiplied by 2, gives the percent of slope. If you use a stick 100 inches long, then the reading on the yardstick would give the percent of slope and you would not need to multiply by 2. XIV. Measure the Slope of a Field 18 |