Clipping Board » Environmental Pollution & Change ─ How dirty the human heart is, how dirty the environment will be...
Update Date: 2008/07/21 18:10
Translated from ENS, USA, Washington, July 15, 2008; Compiled by Hongyan Shi; Reviewed by Liling Cai
Dead Zones Hit Record Highs and Continue to Expand Due to Massive Fertilizer Pollution
The dead zone in the Gulf of Mexico is set to reach a record high in 2008, federal and national scientists reported on July 15, with the surge in U.S. corn production being the primary culprit behind the worsening situation.
A dead zone refers to an area of water with oxygen levels too low to sustain aquatic life. The research team predicts that the dead zone will reach 22,791 square kilometers this summer, roughly the size of New Jersey (Taiwan's area is about 36,000 square kilometers).
The U.S. National Oceanic and Atmospheric Administration (NOAA), the Louisiana Universities Marine Consortium, and Louisiana State University (LSU) forecast that the dead zone will reach its largest extent since official monitoring began in 1985.
The Mississippi River, the largest river in the U.S., irrigates 40% of the country's land, including much of the agricultural heartland and the Corn Belt. Each year, nutrient-rich waters from the river converge off the coasts of Louisiana and Texas to form the dead zone. Further north, in Minnesota, nitrogen and phosphorus from fertilizers flow into rivers and the Gulf of Mexico, causing excessive algae growth. When the algae die and sink to the bottom, they are decomposed by bacteria, consuming large amounts of oxygen and creating hypoxic conditions for other aquatic life.
Rob Magnien, Director of NOAA's Center for Sponsored Coastal Ocean Research, stated, "The strong link between fertilizers and the dead zone indicates that the excessive fertilizer runoff from the Mississippi River in spring is the primary human factor driving the expansion of the dead zone." In 2007, the dead zone reached 7,900 square miles, but a 2002 record showed that the dead zone had already reached 8,500 square miles at that time.
Eugene Turner, a scientist at LSU who led the research team, noted that the unprecedented corn production in the U.S. Midwest has significantly exacerbated the problem. Farmers are planting too much corn and soybeans, allowing nitrogen to easily seep into the soil and contaminate groundwater through crops.
Due to the demand for corn-based ethanol, U.S. corn production has surged in recent years. The U.S. Department of Agriculture estimates that 87 million acres of corn were planted in 2008.
The U.S. Geological Survey (USGS) reported that between April and June, 817,000 metric tons of nitrogen flowed into the Gulf of Mexico, an increase of about 35-45% compared to usual levels. During this period, a record 85,000 metric tons of phosphorus also entered the Gulf, an 85% increase over normal levels.
Turner stated, "This is due to changes in land use. We will need to reduce nitrogen fertilizer use near water bodies." He suggested that farmers remove perennial crops, as they lead to soil overuse, depletion, and increased flood risks. However, even with reduced fertilizer use, the nitrogen already present in the soil will continue to seep into water bodies for years, meaning that immediate improvement is unlikely.Additionally, in February, growers from the National Corn Growers Association (NCGA), conservation organizations, businesses, and the entire agricultural supply chain collaborated to form a pioneering task force aimed at promoting sustainable agricultural practices.
Source: http:/ / tw. news. yahoo. com/ art……rl/ d/ a/ 080721/ 109/ 13n3t. html
Excessive Corn Cultivation Creates Gulf of Mexico 'Dead Zone' Nearly 2/3 Taiwan's Size
Translated from ENS, USA, Washington, July 15, 2008; Compiled by Hongyan Shi; Reviewed by Liling Cai
Dead Zones Hit Record Highs and Continue to Expand Due to Massive Fertilizer Pollution
The dead zone in the Gulf of Mexico is set to reach a record high in 2008, federal and national scientists reported on July 15, with the surge in U.S. corn production being the primary culprit behind the worsening situation.
A dead zone refers to an area of water with oxygen levels too low to sustain aquatic life. The research team predicts that the dead zone will reach 22,791 square kilometers this summer, roughly the size of New Jersey (Taiwan's area is about 36,000 square kilometers).
The U.S. National Oceanic and Atmospheric Administration (NOAA), the Louisiana Universities Marine Consortium, and Louisiana State University (LSU) forecast that the dead zone will reach its largest extent since official monitoring began in 1985.
The Mississippi River, the largest river in the U.S., irrigates 40% of the country's land, including much of the agricultural heartland and the Corn Belt. Each year, nutrient-rich waters from the river converge off the coasts of Louisiana and Texas to form the dead zone. Further north, in Minnesota, nitrogen and phosphorus from fertilizers flow into rivers and the Gulf of Mexico, causing excessive algae growth. When the algae die and sink to the bottom, they are decomposed by bacteria, consuming large amounts of oxygen and creating hypoxic conditions for other aquatic life.
Rob Magnien, Director of NOAA's Center for Sponsored Coastal Ocean Research, stated, "The strong link between fertilizers and the dead zone indicates that the excessive fertilizer runoff from the Mississippi River in spring is the primary human factor driving the expansion of the dead zone." In 2007, the dead zone reached 7,900 square miles, but a 2002 record showed that the dead zone had already reached 8,500 square miles at that time.
Eugene Turner, a scientist at LSU who led the research team, noted that the unprecedented corn production in the U.S. Midwest has significantly exacerbated the problem. Farmers are planting too much corn and soybeans, allowing nitrogen to easily seep into the soil and contaminate groundwater through crops.
Due to the demand for corn-based ethanol, U.S. corn production has surged in recent years. The U.S. Department of Agriculture estimates that 87 million acres of corn were planted in 2008.
The U.S. Geological Survey (USGS) reported that between April and June, 817,000 metric tons of nitrogen flowed into the Gulf of Mexico, an increase of about 35-45% compared to usual levels. During this period, a record 85,000 metric tons of phosphorus also entered the Gulf, an 85% increase over normal levels.
Turner stated, "This is due to changes in land use. We will need to reduce nitrogen fertilizer use near water bodies." He suggested that farmers remove perennial crops, as they lead to soil overuse, depletion, and increased flood risks. However, even with reduced fertilizer use, the nitrogen already present in the soil will continue to seep into water bodies for years, meaning that immediate improvement is unlikely.Additionally, in February, growers from the National Corn Growers Association (NCGA), conservation organizations, businesses, and the entire agricultural supply chain collaborated to form a pioneering task force aimed at promoting sustainable agricultural practices.
Source: http:/ / tw. news. yahoo. com/ art……rl/ d/ a/ 080721/ 109/ 13n3t. html