Earth Gauge: Slow the Flow

Each year, an estimated four billion tons of precious topsoil are lost from America's croplands. When soils make their way into rivers and streams, they can harm aquatic life and impair our drinking water. Additionally, soils can reduce the depth of navigable rivers, and clog reservoirs, which can harm power generation and water supplies. On farmlands, the immediate consequences of erosion can include lower crop yields, increased nitrogen and phosphorous loss, and reduced water-holding capacity, which can increase fertilizer and irrigation costs.

The key to controlling erosion from rain water is to slow the flow of water over agricultural land. If you have cropland that is located on a slope, consider planting your crops across the slope (instead of with the slope), and alternating row crops with forage crops, such as grasses. Planting strips of grasses at regular intervals among row crops forces the flowing water to slow down, which will allow soils carried by the water to settle instead of washing away.

(Sources: United States Department of Agriculture and the United States Environmental Protection Agency. "A Farmer's Guide to Agriculture and Water Quality Issues." Accessed Online 27 March 2008 <http://www.cals.ncsu.edu/wq/wqp/wetlands/wetfactsheets.html>)