In article zHupi.671$zJ4.296@trndny03,
"debnchas" wrote:

http://www.ars.usda.gov/is/pr/2007/070710.htm

Hang on there pardner. You don't haver the only horse in the race.

From the Aug. '07 Scienticic American, "A Return to the Roots".

For many of us in affluent regions, our bath-room scales indicate that
get more than enough to eat, which may lead some to believe that it is
easy, perhaps too easy, for farmers to grow our food. On the
conttrary, modern agriculture requires vast areas of land, along with
regular infusions of water, energy and chemicals. Noting these
resource demands, the 2005 United Nations-sponsored Millennium
Ecosystem Assessment suggested that agriculture may be the
³largest threat to biodiversity and ecosystem function of any single
human activity."

Today most of humanity's food comes directly or indirectly (as animal
feed) from cereal grains, legumes and oilseed crops. These staples are
appealing to producers and consumers because they are easy to
transport and store, relatively imperishable, and fairly high in protein
and calories. As a result such crops occupy about 80 percent of global
agricultural land. But they are all annual plants, must be grown anew
from seeds every year, typically using resource-intensive cultivation
methods. More troubling, the environmental degradation caused by
agriculture will likely worsen as the hungry human population grows to
eight billion or 10 billion in the coming decades. That is why a number
of plant breeders, agronomists and ecologists are working to develop
grain-cropping systems that will function much more like the natural
ecosystems displaced by agriculture. The key to our collective success
is transforming the major grain crops into perennials, which can live
for many years. The idea, actually decades old, may take decades more
to realize, but significant advances in plant-breeding science are
bringing this goal within sight at last.


Roots of the Problem

Most of the farmers, inventors and scientists who have walked farm
fields imagining how to overcome difficulties in cultivation probably
saw agriculture through the lens or' its contemporary successes and
failures. But in the 1970s Kansas plant geneticist Wes Jackson took a
10,00 year step into the past to agriculture with the natural systems
that preceded it. Before humans boosted the abundance of annuals through
domestication and Farming, mixtures of perennial plains dominated nearly
all the planet's landscapes-as they still do in uncultivated areas
today.

More than 85 percent of North America's native plant species, for
example, are perennials. Jackson observed that the perennial grasses and
flowers of Kansas' tall-grass prairies were highly productive year after
year, even as they built and maintained rich soils. They needed no
fertilizers, pesticides or herbicides to thrive while fending off pests
and disease. Water running off or through the prairie soils was clear,
and wildlife was abundant.

In contrast, Jackson saw that nearby fields of annual crops, such as
maize, sorghum, wheat, sunflowers and soybeans, frequent and expensive
care to remain productive. Because annuals have relatively shallow
roots-most of which occur in the top 0.3 meter of soil-and live only
until harvest, many farmed areas had problems with soil erosion,
depletion of soil fertility or water contamination. Moreover, the eerily
quiet farm fields were mostly barren of wildlife. In short, sustaining
annual monocultures in so many places was the problem, and the solution
lay beneath Jackson's boots: hardy and diverse perennial root systems.
----------

Key Facts

o Modern intensive land use quashes natural biodiversity and ecosystems.
Meanwhile the population (human) will balloon to between eight billion
and 10 billion in the coming decades, requiring that more acres be
cultivated.

o Replacing single-season crops with perennials would create large root
systems capable of preserving the soil and would allow cultivation in
areas currently considered marginal.

o The challenge is monumental, but if plant scientists succeed, the
achievement would rival humanity's original domestication of food crops
over the past 10 millennia-and be just as revolutionary.
-The Editors
---------

If annual crops are problematic and natural ecosystems offer
advantages, why do none ofour important grain crops have perennial
roots? The answer lies in the origins of farming. When our
Neolithic ancestors started harvesting seed-bearing plants near their
settlements, several factors probably determined why they favored
annuals.

The earliest annuals to be domesticated, emmer wheat and wild barley,
did have appealingly large seeds. And to ensure a reliable harvest every
year, the first farmers would have replanted some of the seeds they
collected. The characteristics of wild plants can vary greatly, however,
so the seeds of plants with the most desirable traits, such as high
yield, easy threshing and resistance to shattering, would have been
favored. Thus, active cultivation and the unwitting application of
evolutionary selection pressure quickly resulted in domesticated annual
plants with more appealing qualities than their wild annual relatives.
Although some perennial plants might also have had good-size seeds,
they did not need to be replanted and so would not have been subjected
to-or benefited from-the same selection process.

Roots as Solution
Today the traits of perennials are also becoming better appreciated.
With their roots commonly exceeding depths of two meters, perennial
plant communities are critical regulators of ecosystem functions, such
as water management and carbon and nitrogen cycling. Although they
do have to invest energy in maintaining enough underground tissue to
survive the winter, perennial roots spring info action deep within the
soil whenever temperatures are warm enough and nutrients and water
are available. Their constant state of preparedness allows them to be
highly productive yet resilient in the face of environmental stress.
environinental stresses.

In a century-long study of factors affecting soil erosion, timothy
grass, a perennial hay crop, proved roughly 54 times more effective in
maintaining topsoil than annual crops did. Scientists have also
documented a five fold reduction in water loss and a 35-fold reduction
in nitrate loss from soil planted with alfalfa and mixed perennial
grasses as compared with soil under corn and soybeans. Greater root
depths and longer growing seasons also let perennials boost their
sequestration of carbon, the main ingredient of soil organic matter, by
50 percent or more as compared with annually cropped fields. Because
they do no! need to be replanted every year, perennials require fewer
passes of farm machinery and fewer inputs of pesticides and
fertilizers as well, which reduces fossil-fuel use. The plants thus
lower the amount ol' carbon dioxide in the air while improving the
soil's fertility.

Herbicide costs for annual crop production may be four to 8.5 times
the herbicide costs for perennial crop prodiiclion, so fewer inputs in
perennial systems mean lower cash expenditures for the farmer.
Wildlife also benefits: bird populations, for instance, have been shown
to be seven times more dense in perennial crop fields than in annual
crop fields. Perhaps most important for a hungry world, perennials are
far more capable of sustainable cultivation on marginal lands, which
already have poor soil quality or which would be quickly depleted by a
few years of intensive annual cropping. For all these reasons, plant
breeders in the U.S. and elsewhere have initiated research and breeding
programs over the past five years to develop wheat, sorghum,
sunflower, intermediate wheatgrass and other species as perennial
grain crops. When compared with research devoted to annual crops,
perennial grain development is still in the toddler stage . Taking
advantage of the significant advances in plant breeding over the past
two or three decades, however, will make the large-scale development
of high-yield perennial grain crops feasible within the next 25 to 50
years.

Perennial crop developers are employing essentially the same two
methods as those used by many other agricultural scientists: direct
domestication of wild plants and hybridization of existing annual crop
plants with their wild relatives. These techniques are potentially
complementary, but each presents a distinct set of challenges and
advantagess as well.
----------

The entire article is in the Aug. '07 Scienticic American, now at your
newstands ot it will be posted on the Scienticic American web site in a
month or two.
--
Billy
http://angryarab.blogspot.com/