Living on Earth’s Jennifer Chu reports on research that could help hog farmers clean up their waste.
CURWOOD: Coming up: biomonitoring – a movement to help people find out how many PCB’s and other chemicals are in their bodies. First, this Note on Emerging Science from Jennifer Chu.
[SCIENCE NOTE THEME]
CHU: Anyone who lives near a hog farm will tell you the smell isn’t pretty. The source of that smell is large open pits filled with hog waste that’s been flushed out of hog houses. In recent years, many of these pits have been decommissioned. For instance, in North Carolina there are 1,700 inactive sites.
To clean up these pits, farmers have to drain the liquid and then truck the solid waste away for use as fertilizer. But farmers complain this process is very costly. Now, there may be a cheaper and greener solution to this disposal problem: poplar trees.
Researchers in North Carolina have taken a half-acre pit, drained out the liquid, filled the hole with soil and planted over 300 poplar trees. The roots of these trees grow faster and deeper than most others, and scientists have found they can absorb 3,000 gallons of sludge per acre per day. This sludge contains nutrients for the trees, such as nitrogen and phosphorus. The heavy metals in the waste, like copper and zinc, are stored in the trees’ tissue.
Researches believe the trees will act as a sponge and prevent these contaminants from leaking into groundwater. Hog farmers can opt to harvest the trees for lumber once the site is completely cleaned up. Scientists estimate that would take up to 15 years.
That’s this week’s Note on Emerging Science, I’m Jennifer Chu.
CURWOOD: And you're listening to Living on Earth.
Living on Earth wants to hear from you!
P.O. Box 990007
Boston, MA, USA 02199
Donate to Living on Earth!
Living on Earth is an independent media program and relies entirely on contributions from listeners and institutions supporting public service. Please donate now to preserve an independent environmental voice.
Sailors For The Sea: Be the change you want to sea.
Innovating to make the world a better, more sustainable place to live. Listen to the race to 9 billion
The Grantham Foundation for the Protection of the Environment: Committed to protecting and improving the health of the global environment.
Energy Foundation: Serving the public interest by helping to build a strong, clean energy economy.
Contribute to Living on Earth and receive, as our gift to you, an archival print of one of Mark Seth Lender's extraordinary hummingbird photographs. Follow the link to see Mark's current collection of photographs.