
Read: More
about the research in Agricultural Research magazine. Helping Farmers Meet Today's Environmental
ChallengesBy Don Comis January 11, 2000A U.S. Department of Agriculture water quality
project is changing the landscape of American agriculture. The program, begun
in 1990 to reduce the amount of pesticides reaching groundwater, expanded three
years ago to address broader environmental concerns, including harmful algal
blooms. These blooms have created a widening "dead zone" in the Gulf
of Mexico, where lack of oxygen kills shellfish. Pfiesteria and Red Tide algal
blooms also have been implicated in fish-kills along the east coast. Reducing nitrogen loadings into the Mississippi River by 20 to 30 percent
could increase oxygen levels in the Gulf by 15 to 50 percent, according to the
National
Science and Technology Council's recent Integrated Assessment Report. The USDA water quality program continues to show farmers how to reduce
nitrogen loadings from commercial fertilizer and animal manure. Suggested
approaches include: - Split applications of nitrogen fertilizer.
- Testing plants for nitrogen deficiency with a portable meter.
- Applying nitrogen at a variable rate.
- Adding a disk to nitrogen fertilizer applicators to mound soil, keeping
nitrate out of groundwater.
- Using wood chips and alfalfa to catch excess nitrate from drainage pipes.
- Reusing drainage and surface runoff water to irrigate, after filtering
through an artificial wetland.
- Running irrigation water through drainage pipes in the summer to stop
leaching of nitrates and pesticides.
The program originally involved large Midwestern sites called
Management Systems
Evaluation Areas (MSEA). The 1996 merger with USDA's Agricultural Systems
for Environmental Quality brought in concerns about phosphorus, air quality,
soil management, and off-site impacts. The merger also brought in Ohio's Lake
Erie Basin, the Mississippi Delta region, and the eastern coastal plain. A story about the research appears in the January Agricultural Research magazine.
Click here to
view it on the web. Scientific contact: Dale A. Bucks, ARS National Program Leader for
Water Quality and
Management, Beltsville, Md., phone (301) 504-7034, fax (301) 504-6231,
[email protected]. U.S. Department of Agriculture |