Filter strip

Filter strips, also referred to as buffer strips, are small, edge-of-field tracts of vegetated land that are used to reduce the contamination of surface water. They are primarily used in agriculture to control non-point source pollution, however, they may also be used to reduce sediment in storm water runoff from construction sites. There are several types of filter strips including vegetative filter strips, forested riparian buffers, and wind buffers. In agriculture, they are highly effective in reducing the concentration of nitrogen (N) and phosphorus (P) in runoff into surface water and are also effective in reducing sediment erosion and removing pesticides. This helps to prevent eutrophication and associated fishkills and loss of biodiversity. The use of filter strips is very common in developed countries and is required by law in some areas. The implementation and maintenance of filter strips is inexpensive and their use has been shown to be cost effective. Filter strips, also referred to as buffer strips, are small, edge-of-field tracts of vegetated land that are used to reduce the contamination of surface water. They are primarily used in agriculture to control non-point source pollution, however, they may also be used to reduce sediment in storm water runoff from construction sites. There are several types of filter strips including vegetative filter strips, forested riparian buffers, and wind buffers. In agriculture, they are highly effective in reducing the concentration of nitrogen (N) and phosphorus (P) in runoff into surface water and are also effective in reducing sediment erosion and removing pesticides. This helps to prevent eutrophication and associated fishkills and loss of biodiversity. The use of filter strips is very common in developed countries and is required by law in some areas. The implementation and maintenance of filter strips is inexpensive and their use has been shown to be cost effective. Filter strips are primarily used in agriculture to control nonpoint source pollution. They function by decreasing the velocity of water, allowing runoff and dissolved inorganic molecules to infiltrate the soil. Vegetation then uptakes these inorganic molecules, notably nitrogen and phosphorus, reducing their concentrations in nearby surface water. Filter strips may also be used as sediment traps to reduce sediment in storm water runoff from construction sites. Eutrophication in a lake caused by nonpoint pollution from agricultureFilter strips are commonly used to prevent eutrophication in surface waters. Eutrophication is a widespread problem in rivers, lakes, estuaries, and coastal oceans, directly caused by the over-enrichment of nitrogen and phosphorus; the source of which is overwhelmingly nonpoint pollution from agriculture. The excess of these nutrients leads to uncontrolled growth of plants and algae (and phytoplankton in saltwater environments). As they are decomposed by microorganisms, oxygen is depleted, resulting in hypoxia. This can lead to fishkills and the mass deaths of other fauna, creating a state of severely reduced biodiversity. By reducing the concentration of chemical fertilizers in surface water, filter strips have a positive effect on human health. Although elevated concentrations of phosphorus in water is not directly toxic to humans, nitrates poses a serious risk to human health. At high concentrations, the ingestion of nitrates can result in an acute condition known as methemoglobinemia in which the oxygen carrying capacity of hemoglobin is impaired. Infants are especially susceptible, which is why the disease is colloquially referred to as 'blue baby syndrome.'