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Dear
EarthTalk: What are the environmental benefits
of the hydroponic growing of lettuce and other crops?
--Bruce
Keeler, Oakland, Calif.
While
organic agriculture is all the rage, growing by leaps and
bounds to meet increased consumer demand for healthier food,
another option that's less well known but just as healthy
is hydroponics, whereby plants are grown in nutrient-fortified
water-based solutions without a soil substrate whatsoever.
Besides not needing chemical fertilizers or pesticides (most
of which are toxic as well as derived from petroleum), hydroponics
also take up much less space than traditional agriculture,
meaning that even an apartment window can yield impressive
amounts of food throughout the calendar year.
In
traditional forms of agriculture, soil facilitates the process
of providing the mineral nutrients that plants need to grow.
Organisms in the soil break down the nutrients into inorganic
basic forms that the plants can then take up accordingly
and put to use photosynthesizing. Of course, some of the
organisms the soil attracts are unwelcome, and not every
speck of soil is ideal as a growth medium, so we have come
up with ways to kill off unwanted pests (pesticides) and
pump up the ground's productivity (fertilizers).
But
growing fruits and vegetables hydroponically obviates the
need for fertilizers and pesticides — let alone soil
— altogether. "Without soil, there is little
to no microbial activity, so the plants depend on direct
nutrients from nutrient solutions," reports Alexandra
Gross in E – The Environmental Magazine. "And
because hydroponics occur in a highly controlled space and
microbial activity is at minimum, pesticides, insecticides
and herbicides are not needed."
In
most hydroponic systems, the nutrient solutions include
inorganic salt fertilizers and semi-soluble organic materials
such as bat guano (manure), bone meal and fish emulsion.
Since growing hydroponically does not require chemical fertilizers
and pesticides, the method is inherently "organic,"
although the federal government doesn't recognize it as
such officially. Hydroponic farmers are trying to get the
U.S. Food & Drug Administration to take soil out of
the equation when it comes to defining organic so that their
products can bear an organic certification label on store
shelves and appeal to a quickly growing segment of green-minded
consumers.
Hydroponic
methods are becoming especially popular with a new wave
of green-minded urban gardeners. When artist Britta Riley
began growing her own food hydroponically in the window
of her fifth floor Brooklyn apartment in 2009 — and
sharing her findings with like-minded folks all over the
world via the Internet — the Windowfarms Project was
born. In less than two years, some 13,000 people have joined
the online community at the windowfarms.org
website, where members can download free how-to instructions
for homemade hydroponic systems.
Along
with the Windowfarms Project website, a couple of good sources
of hydroponic growing information, inspiration and supplies
include Hydroponics Online and Simply Hydroponics and Organics.
CONTACTS:
The
Windowfarms Project, www.windowfarms.org;
Hydroponics Online, www.hydroponicsonline.com;
Simply Hydroponics and Organics, www.simplyhydro.com.
Dear
EarthTalk: What is the U.S. military doing
to reduce its carbon footprint and generally green its operations?
-- Anthony Gomez, New York, NY
As the world’s
largest polluter, the U.S. military has its work cut out
for it when it comes to greening its operations. According
to the nonprofit watchdog group, Project Censored, American
forces generate some 750,000 tons of toxic waste annually—more
than the five largest U.S. chemical companies combined.
Although this pollution occurs globally on U.S. bases in
dozens of countries, there are tens of thousands
of toxic “hot spots” on some 8,500 military
properties right here on America soil.
“Not only
is the military emitting toxic material directly into the
air and water,” reports Project Censored, “it’s
poisoning the land of nearby communities, resulting in increased
rates of cancer, kidney disease, increasing birth defects,
low birth weight and miscarriage.” The non-profit
Military Toxics Project is working with the U.S. government
to identify problem sites and educate neighbors about the
risks.
Meanwhile, the
U.S. military manages 25 million acres of land that provides
habitat for some 300 threatened or endangered species. The
military has harmed endangered animal populations by bomb
tests (and been sued for it), reports Project Censored,
and military testing of low-frequency underwater sonar technology
has been implicated in the stranding deaths of whales worldwide.
Despite being linked to such problems, the U.S. Department
of Defense (DoD) has repeatedly sought exemptions from Congress
for compliance with federal laws including the Migratory
Bird Treaties Act, the Wildlife Act, the Endangered Species
Act, the Clean Air Act and the National Environmental Policy
Act.
It’s unclear
whether the U.S. military is taking heed of criticisms in
regard to pollution and endangered species management, but
it is undoubtedly concerned about climate change, as its
effects on the environment could lead to unprecedented natural
resource wars and mass migrations of people. And reducing
our reliance on potentially hostile foreign oil sources
is a short term national security imperative as well. A
recent Obama administration directive calls for the DoD
to draw 20 percent of its power from renewable sources by
2020. Nikihl Sonnad of the GreenFuelSpot website reports
that the Army and Air Force are planning to include solar
arrays on several bases in sunny western states. The Air
Force is also building the nation’s largest biomass
energy plants in Florida and Georgia, and the Navy is building
three large geothermal energy plants and funding research
into extracting energy from ocean waves.
Some of the military’s
R&D into renewables is for battlefield applications.
Outfitting troops with the capability to produce their own
on-site power from solar and wind sources not only makes
sourcing oil less of a necessity but also should serve to
reduce casualties from fuel transport operations. Over 1,000
American troops have lost their lives delivering fuel in
the past few years alone (in part because enemy combatants
often use fuel trucks as attack targets), says Sonnad.
Elisabeth Rosenthal reports in The New York Times that “there
is great hope that some of the renewable energy technology
being developed for battle will double back and play a role
in civilian life.” She adds that the armed forces
have enough purchasing power to create genuine markets in
the non-military world.
CONTACTS:
Project
Censored; U.S.
DoD; Military
Toxics Project; GreenFuelSpot.
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