Water table management for water quality improvement

WATER quality in streams and groundwater is among the most critical environmental concerns in the United States and elsewhere. The U.S. Department of Agriculture's Agricultural Research Service (ARS), U.S. Geological Survey (USGS), Experiment Station Committee on Organization and Policy (ESCOP), and other institutions have research and extension priorities directed toward protecting surface water and groundwater resources. In the mid-1980s, ESCOP commissioned a task force to establish a groundwater quality initiative for the entire United States ( 13 ). In the report of that task force, groundwater quality issues were separated by region: West, South, North Central, and Northeast. In all areas, the top research and extension priorities included the evaluation of the source, fate, remedial treatment, and impacts of agricultural pesticides and nitrates. Agriculture is considered a major contributor to water quality problems (4, 5, 25, 35, 38, 41, 43, 51). Improved surface and subsurface drainage has been associated with water quality problems in streams and lakes (2, 9, 18, 28, 36). Research indicates that nitrogen losses increased due to drainage of relatively heavy agricultural soils in Ohio, but sediment and other nutrient losses decreased (42). Studies on a Commerce silt loam in southern Louisiana showed that …