I am always skeptical of such broad claims, and solutions that don't get at
the "root" of the problem, but perhaps folks here will find this of

Crop breeding could ‘slash CO2 levels’

03 August 2011 Manchester, The University

Breeding crops with roots a metre deeper in the ground could lower
atmospheric CO2 levels dramatically, with significant environmental
benefits, according to research by a leading University of Manchester

Writing in the journal Annals of Botany, Professor Douglas Kell argues that
developing crops that produce roots more deeply in the ground could harvest
more carbon from the air, and make crops more drought resistant, while
dramatically reducing carbon levels.

In principle, any crops could be treated in this way, giving more productive
yields while also being better for the environment.

Although the amount of carbon presently sequestered in the soil in the
natural environment and using existing crops and grasses has been known for
some time, Professor Kell’s new analysis is the first to reveal the benefits
to the environment that might come from breeding novel crops with root
traits designed to enhance carbon sequestration.

Professor Kell, Professor of Bioanalytical Science at the University as well
as Chief Executive of the Biotechnology and Biological Sciences Research
Council (BBSRC), has also devised a carbon calculator that can show the
potential benefits of crops that burrow more deeply in the ground.

With this, he has calculated that – depending on the time it takes them to
break down –breeding crops that could cover present cropland areas but that
had roots a metre deeper in the soil could double the amount of carbon
captured from the environment. This could be a significant weapon in the
fight against climate change.

The soil represents a reservoir that contains at least twice as much carbon
as does the atmosphere, yet mainly just the above-ground plant biomass is
harvested in agriculture, and plant photosynthesis represents the effective
origin of the overwhelming bulk of soil carbon.

Breeding crop plants with deeper and bushy root ecosystems could
simultaneously improve both the soil structure and its steady-state carbon,
water and nutrient retention, as well as sustainable plant yields.

Professor Kell argues that widespread changes in agricultural practice are
needed, in an environment in which edible crop yields also need to increase
substantially and sustainably, and where transport fuels and organic
chemicals will need to come from modern (rather than fossil) photosynthesis.

It is known that massive CO2 reductions in the atmosphere over geological
time have happened because of the rise of deep-rooted trees and flowering

Most cultivated agricultural crops have root depths that do not extend much
beyond one metre.  Doubling this, Professor Kell argues, would dramatically
reduce CO2 levels.

Existing studies, which have doubted the benefits of deep roots in carbon
sequestration, do not make soil measurements much below a metre, and the
kinds of root depths proposed by Professor Kell would more than double that.

He said: “This doubling of root biomass from a nominal 1m to a nominal 2m is
really the key issue, together with the longevity of the roots and carbon
they secrete and sequester below-ground.

“What matters is not so much what is happening now as what might be achieved
with suitable breeding of plants with deep and reasonably long-lived roots.
Many such plants exist, but have not been bred for agriculture.

“In addition to the simple carbon sequestration that this breeding could
imply – possibly double that of common annual grain crops – such plants seem
to mobilise and retain nutrients and water very effectively over extended
periods, thus providing resistance to drought, flooding and other challenges
we shall face from climate change.

“While there is a way to go before such crops might have, for example, the
grain yields of present day cereals, their breeding and deployment seems a
very promising avenue for sustainable agriculture.”
 Attached files

   - <>

   Breeding deeper roots could slash CO2 levels

   - *Full bibliographic information*The paper, Breeding crop plants with
   deep roots: their role in sustainable carbon, nutrient and water
   sequestration, by Douglas B. Kell, is being published in the September issue
   of Annals of Botany (volume 108, issue 3) and is freely available online at or from the Press Office.

Michael Balter
Contributing Correspondent, Science
Adjunct Professor of Journalism,
New York University

Email:  [log in to unmask]

“Faced with the choice between changing one’s mind and proving that there is
no need to do so, almost everyone gets busy on the proof."
                                                  --John Kenneth Galbraith