Low dose rotten egg gas can double food output

[hab...@anony.net]

http://www.sciencedaily.com/releases/2013/04/130417185531.htm

At high concentrations -- levels of 30 to 100 parts per million in
water -- hydrogen sulfide can be lethal to humans. At one part per
million it emits a telltale rotten-egg smell. Dooley used a
concentration of 1 part per billion or less to water seeds of peas,
beans and wheat on a weekly basis. Treating the seeds less often
reduced the effect, and watering more often typically killed them.

With wheat, all the seeds germinated in one to two days instead of
four or five, and with peas and beans the typical 40 percent rate of
germination rose to 60 to 70 percent.

"They germinate faster and they produce roots and leaves faster.
Basically what we've done is accelerate the entire plant process," he
said.

Crop yields nearly doubled, said Peter Ward, Dooley's doctoral
adviser, a UW professor of biology and of Earth and space sciences and
an authority on Earth's mass extinctions.

Hydrogen sulfide, probably produced when sulfates in the oceans were
decomposed by sulfur bacteria, is believed to have played a
significant role in several extinction events, in particular the
"Great Dying" at the end of the Permian period. Ward suggests that the
rapid plant growth could be the result of genetic signaling passed
down in the wake of mass extinctions.

At high concentrations, hydrogen sulfide killed small plants very
easily while larger plants had a better chance at survival, he said,
so it is likely that plants carry a defense mechanism that spurs their
growth when they sense hydrogen sulfide.

"Mass extinctions kill a lot of stuff, but here's a legacy that
promotes life," Ward said.

Dooley recently has applied hydrogen sulfide treatment to corn,
carrots and soybeans with results that appear to be similar to earlier
tests. But it is likely to be some time before he, and the general
public, are comfortable with the level of testing to make sure there
are no unforeseen consequences of treating food crops with hydrogen
sulfide.

The most significant near-term promise, he believes, is in growing
algae and other stock for biofuels. Plant lipids are the key to
biofuel production, and preliminary tests show that the composition of
lipids in hydrogen sulfide-treated plants is the same as in untreated
plants, he said.

When plants grow to larger-than-normal size, they typically do not
produce more cells but rather elongate their existing cells, Dooley
said. However, in the treatment with hydrogen sulfide, he found that
the cells actually got smaller and there were vastly more of them.
That means the plants contain significantly more biomass for fuel
production, he said.