permaculture

["Lawrence F. London, Jr." <lflj@intrex.net>]

Tomatoes Grown in Seawater Healthier Than Regular Kind
http://www.foxnews.com/story/0,2933,260468,00.html?sPage=fnc.science/naturalscience

Tomatoes irrigated with diluted seawater grow with significantly higher 
levels of
healthy antioxidant compounds, new research shows.

"It'd be interesting to see if this might be a more general phenomenon, where 
a little
salt induces antioxidants in lots of crops," said botanist Edward Glenn at the
University of Arizona, who did not participate in the new study. "There could 
be a
consumer wave toward salt-tolerant crops based on their nutritional 
properties."

The option to use salty water on crops might help farmers deal with growing 
irrigation
woes. Irrigation water, as well as drinking water, is growing scarce and 
deteriorating
in quality around the world.

Nearly 70 percent of all available freshwater is used for agriculture. Use of 
water for
irrigation has increased globally by more than 60 percent since 1960, 
according to
United Nation statistics.

At the same time, poor irrigation and drainage practices have led to salt 
buildup in
roughly one-eighth of all irrigated land.

Although desalination plants that remove salt from saltwater now exist, they 
remain
expensive. For example, distillation processes that separate out any 
dissolved minerals
by boiling and condensing water require costly amounts of fuel.

Riccardo Izzo at the University of Pisa in Italy and his colleagues reasoned 
that
diluted saltwater could drive crops to generate more healthy antioxidants, 
such as
vitamins C or E. Plants generate antioxidants to protect themselves when 
stressed out by
salt, drought or various other burdens.

The researchers investigated tomatoes, which are grown worldwide and are 
moderately
saline-tolerant. They grew various types of tomatoes, including those 
commonly used for
salads, under different levels of salinity and investigated the fruit for 
nutrients.

The researchers found that growing tomatoes in 10 percent seawater improved 
antioxidant
levels significantly, findings they detailed in the April 4 issue of the 
Journal of
Agricultural and Food Chemistry.

Glenn noted the water that percolates out from normally irrigated soil, 
technically
known as irrigation return flow, is often as salty as 10 percent seawater.

"About a third of irrigation water becomes irrigation return flow, so there's 
a huge
amount of this brackish water, and this research now suggests this could get 
reused for
crops," Glenn told LiveScience.

For decades, research has shown that seawater can irrigate crops, "but 
there's an
impression [that] the crops seawater can irrigate are low value," Glenn said. 
"Farmers
want a good return for their investment and time, and tomatoes are really 
high value.
Also, crops like tomatoes are sold based on consumer appeal, and if you have 
an extra
going for you like high antioxidant levels, this could be quite valuable."