Tuesday, January 5, 2010

Norway Protocol Stops Super Bugs






This is a rather important empirical result that deserves respect and is also unexpected.  Worse, this is the first time I have even heard of this protocol and the result.

 

What it means, and it should have been inferred, is that mutant bacteria arise in an antibacterial environment such as a hospital but lack survivability in the wild.

 

The present arms race with antibiotics can be arrested by following the Norwegian protocol.  The real promise here though is that our huge battery of apparent ineffective antibiotic systems can be largely restored at the same time.

 

I imagine that it will be impossible to change things in the USA were it is totally gamed by the drug industry, but it should be possible just about everywhere else.

 

Our modern world blesses us with blanket exposure to a huge array of potential global pathogens for which we develop immunity.  It generally only gets out of hand where a population has been isolated.  That plausibly describes conditions in a hospital were external pathogens are aggressively excluded.  View this as a cautionary thought.

 

Solution to killer superbug found in Norway


When drugs stop working, last of a five-part series
Thursday, December 31, 2009 | 10:20 p.m. CST


EDITOR'S NOTE: Once-curable diseases such as tuberculosis and malaria are coming back, as germs rapidly mutate to form aggressive strains that resist drugs. The reason: The misuse of the very drugs that were supposed to save us has built up drug resistance worldwide.  This is the last of a five-part series.

OSLO, NorwayAker University Hospital is a dingy place to heal. The floors are streaked and scratched. A light layer of dust coats the blood pressure monitors. A faint stench of urine and bleach wafts from a pile of soiled bedsheets dropped in a corner.
Look closer, however, at a microscopic level, and this place is pristine. There is no sign of a dangerous and contagious staph infection that killed tens of thousands of patients in the most sophisticated hospitals of Europe, North America and Asia this year, soaring virtually unchecked.
The reason: Norwegians stopped taking so many drugs.
Twenty-five years ago, Norwegians were also losing their lives to this bacteria. But Norway's public health system fought back with an aggressive program that made it the most infection-free country in the world. A key part of that program was cutting back severely on the use of antibiotics.
Now a spate of new studies from around the world prove that Norway's model can be replicated with extraordinary success, and public health experts are saying these deaths — 19,000 in the U.S. each year alone, more than from AIDS — are unnecessary.
"It's a very sad situation that in some places so many are dying from this, because we have shown here in Norway that Methicillin-resistant Staphylococcus aureus can be controlled and with not too much effort," said Jan Hendrik-Binder, Oslo's MRSA medical adviser. "But you have to take it seriously, you have to give it attention and you must not give up."
The World Health Organization says antibiotic resistance is one of the leading public health threats on the planet. A six-month investigation by The Associated Press found overuse and misuse of medicines has led to mutations in once-curable diseases like tuberculosis and malaria, making them harder, and in some cases impossible, to treat.
 Norway's simple solution offers glimmer of hope
 
John Birger Haug shuffles down Aker's scuffed corridors, patting the pocket of his baggy white scrubs. "My bible," the infectious disease specialist says, pulling out a little red Antibiotic Guide that details this country's impressive MRSA solution.
It's what's missing from this book — an array of antibiotics — that makes it so remarkable.
"There are times I must show these golden rules to our doctors and tell them they cannot prescribe something, but our patients do not suffer more and our nation, as a result, is mostly infection free," he says.
Norway's model is surprisingly straightforward:
§             Norwegian doctors prescribe fewer antibiotics than any other country, so people do not have a chance to develop resistance to them.
§             Patients with MRSA are isolated, and medical staff who test positive stay at home.
§             Doctors track each case of MRSA by its individual strain, interviewing patients about where they've been and who they've been with, testing anyone who has been in contact with them.
Haug unlocks the dispensary, a small room lined with boxes of pills, bottles of syrups and tubes of ointment. What's here? Medicines considered obsolete in many developed countries. What's not? Some of the newest, most expensive antibiotics, which aren't even registered for use in Norway, "because if we have them here, doctors will use them," he says.
He points to an antibiotic. "If I treated someone with an infection in Spain with this penicillin I would probably be thrown in jail," he says, "and rightly so because it's useless there."
Norwegians are sanguine about their coughs and colds, toughing it out through low-grade infections.
"We don't throw antibiotics at every person with a fever. We tell them to hang on, wait and see, and we give them a Tylenol to feel better," says Haug.
Convenience stores in downtown Oslo are stocked with an amazing and colorful array — 42 different brands at one downtown 7-Eleven — of soothing, but nonmedicated, lozenges, sprays and tablets. All workers are paid on days they, or their children, stay home sick. And drug makers aren't allowed to advertise, reducing patient demands for prescription drugs.
In fact, most marketing here sends the opposite message: "Penicillin is not a cough medicine," says the tissue packet on the desk of Norway's MRSA control director,  Petter Elstrom.
He recognizes his country is "unique in the world and best in the world" when it comes to MRSA. Less than 1 percent of health care providers are positive carriers of MRSA staph.
But Elstrom worries about the bacteria slipping in through other countries. Last year almost every diagnosed case in Norway came from someone who had been abroad.
"So far we've managed to contain it, but if we lose this, it will be a huge problem," he said. "To be very depressing about it, we might in some years be in a situation where MRSA is so endemic that we have to stop doing advanced surgeries, things like organ transplants, if we can't prevent infections. In the worst-case scenario we are back to 1913, before we had antibiotics."
Norway cut antibiotic use in the 1980s, lowered rate of staph infection
Forty years ago, a new spectrum of antibiotics enchanted public health officials, quickly quelling one infection after another. In wealthier countries that could afford them, patients and providers came to depend on antibiotics. Trouble was, the more antibiotics are consumed, the more resistant bacteria develop.
Norway responded swiftly to initial MRSA outbreaks in the 1980s by cutting antibiotic use. Thus while they got ahead of the infection, the rest of the world fell behind.
In Norway, MRSA has accounted for less than 1 percent of staph infections for years. That compares to 80 percent in Japan, the world leader in MRSA; 44 percent in Israel; and 38 percent in Greece.
In the U.S., cases have soared, and MRSA cost $6 billion last year. Rates have gone up from 2 percent in 1974 to 63 percent in 2004. And in the United Kingdom, they rose from about 2 percent in the early 1990s to about 45 percent, although an aggressive control program is now starting to work.
About 1 percent of people in developed countries carry MRSA on their skin. Usually harmless, the bacteria can be deadly when they enter a body, often through a scratch. MRSA spreads rapidly in hospitals where sick people are more vulnerable, but there have been outbreaks in prisons, gyms, even on beaches. When dormant, the bacteria are easily detected by a quick nasal swab and destroyed by antibiotics.
John Jernigan at the U.S. Centers for Disease Control and Prevention said they incorporate some of Norway's solutions in varying degrees, and his agency "requires hospitals to move the needle, to show improvement, and if they don't show improvement they need to do more."
And if they don't?
"Nobody is accountable to our recommendations," he said, "but I assume hospitals and institutions are interested in doing the right thing."
Barry Farr, a retired epidemiologist who watched a successful MRSA control program launched 30 years ago at the University of Virginia's hospitals, blamed the CDC for clinging to past beliefs that hand-washing is the best way to stop the spread of infections like MRSA. He says it's time to add screening and isolation methods to their controls.
The CDC needs to "eat a little crow and say, 'Yeah, it does work,'" he said. "There's example after example. We don't need another study. We need somebody to just do the right thing."
British, Japanese doctors see staph infection rates plummet
But can Norway's program really work elsewhere?
The answer lies in the busy laboratory of an aging little public hospital about 100 miles outside of London. It's here that microbiologist Lynne Liebowitz got tired of seeing the stunningly low Nordic MRSA rates while facing her own burgeoning cases.
So she turned Queen Elizabeth Hospital in King's Lynn into a petri dish, asking doctors to almost completely stop using two antibiotics known for provoking MRSA infections.
One month later, the results were in: MRSA rates were tumbling. And they've continued to plummet. Five years ago, the hospital had 47 MRSA bloodstream infections. This year they've had one.
"I was shocked, shocked," says Liebowitz, bouncing onto her toes and grinning as colleagues nearby drip blood onto slides and peer through microscopes in the hospital laboratory.
When word spread of her success, Liebowitz's phone began to ring. So far she has replicated her experiment at four other hospitals, all with the same dramatic results.
"It's really very upsetting that some patients are dying from infections which could be prevented," she says. "It's wrong."
Around the world, various medical providers have also successfully adapted Norway's program with encouraging results. A medical center in Billings, Mont., cut MRSA infections by 89 percent by increasing screening, isolating patients and making all staff — not just doctors — responsible for increasing hygiene.
In Japan, with its cutting-edge technology and modern hospitals, about 17,000 people die from MRSA every year.
Satoshi Hori, chief infection control doctor at Juntendo University Hospital in Tokyo, says doctors overprescribe antibiotics because they are given financial incentives to push drugs on patients.
Hori now limits antibiotics only to patients who really need them and screens and isolates high-risk patients. So far his hospital has cut the number of MRSA cases by two-thirds.
In 2001, the CDC approached a Veterans Affairs hospital in Pittsburgh about conducting a small test program. It started in one unit, and within four years, the entire hospital was screening everyone who came through the door for MRSA. The result: an 80 percent decrease in MRSA infections. The program has now been expanded to all 153 VA hospitals, resulting in a 50 percent drop in MRSA bloodstream infections, said Robert Muder, chief of infectious diseases at the VA Pittsburgh Healthcare System.
"It's kind of a no-brainer," he said. "You save people pain, you save people the work of taking care of them, you save money, you save lives and you can export what you learn to other hospital-acquired infections."
Pittsburgh's program has prompted all other major hospital-acquired infections to plummet as well, saving roughly $1 million a year.
"So, how do you pay for it?" Muder asked. "Well, we just don't pay for MRSA infections, that's all."
Fighting for antibiotics precautions
Beth Reimer of Batavia, Ill., became an advocate for MRSA precautions after her 5-week-old daughter Madeline caught a cold that took a fatal turn. One day her beautiful baby had the sniffles. The next?
"She wasn't breathing. She was limp," the mother recalled. "Something was terribly wrong."
MRSA had invaded her little lungs. The antibiotics were useless. Madeline struggled to breathe, swallow, survive, for two weeks.
"For me to sit and watch Madeline pass away from such an aggressive form of something, to watch her fight for her little life — it was too much," Reimer said.
Since Madeline's death, Reimer has become outspoken about the need for better precautions, pushing for methods successfully used in Norway. She's stunned, she said, that anyone disputes the need for change.
"Why are they fighting for this not to take place?" she said.
Martha Mendoza is an AP national writer who reported from Norway and England. Margie Mason is an AP medical writer based in Vietnam, who reported while on a fellowship from The Nieman Foundation at Harvard University.


Monday, January 4, 2010

2009 Reversal





Last year at this time, the global warming crowd where triumphant and they were successfully shouting down any reasoned opposition.  Their hubris had reached the point of declaring the science settled and that thousands of scientists actually agreed with this position.  I thought that a little remarkable at the time since science is instinctually contrarian unless they are selling you on a grant request.  The corollary of that line of thinking suggested that the whole scheme was a grant request rather than actual science.

 

I expected the so called science was going to be chipped away by the facts and that certainly was happening.  I did not expect the deluge that actually ensued.  The last real bastion of questionable climate science was revealed through the email scandal as something much different than an honest mistake.  It certainly was not science.

 

In the end, not only is all the published data presently suspect but apparently lots of data has been destroyed.  Now it is not likely quite that ugly once the data is properly reconstructed (if it can) but for the present, you likely have more trustworthy data than these clowns have left us with.

 

During the year, I also discovered just how persuasively USA weather data had been corrupted by local changes (seventy percent of sites affected) and that various corrective measures had been taken from time to time in such a way as to make trend lines dicey at best.  This was supposed to be the gold standard and it looked more like the lead standard green with age.

 

The point I am making is that our best data is scary at times, long before someone gets creative.  If you are lucky, you can generate a statistically significant difference between decades.  The truth about that is that you do not need stacks of data to figure that out.  We all know what a warm year looks like.  This winter we have been getting our butts kicked with winter storm after winter storm and we just finished December.  I still hope for an early spring, but this year I mean it.

 

2009: The year climate change and global warming activists would like to forget

December 31, 10:48 AMClimate Change ExaminerTony Hake


For those who believe the manmade climate change theory, the new year cannot get here fast enough. As 2009 comes to a close, many are faced with the realizations that not only are they losing in the court of public opinion, the ‘consensus’ about anthropogenic global warming is far from solid. The year saw preeminent scientists join the chorus of those saying that other drivers besides man influence the climate, a scandal erupted that shook the very foundation of climate science and a much touted climate summit fell into disarray.

As 2009 dawned, climate change advocates continued to sound the alarm about carbon dioxide’s accumulation in the atmosphere and the warming they believe it causes. With President Barack Obama taking office in January, it was thought their brand of climate science would find a new foothold on which to advance the cause. As Obama prepared to take office, Dr. James Hansen sent the president-elect a letter warning of the dire consequences at hand saying that he had four years to save the world.


Or be notified by email when a new article from the Climate Change Examiner is posted.  Click the 'Subscribe' link at the top or bottom of the article and enter your email address.


All seemed to be pointing toward a banner year for the advancement of the manmade climate change theory. The National Oceanic and Atmospheric Administration (NOAA) announced that the year prior, 2008, was the eighth warmest on record for the globe. The United States however saw its coldest temperatures in 10 years but that mattered little.

High hopes were soon dashed as many noted scientists and public figures raised their voices in dissent. From meteorologists to geologists to climate scientists, those who don’t agree with the theory refused to be silenced.

John Coleman, founder of the Weather Channel, railed against the manmade climate change theory calling it a hoax and ‘bad science.’ Former astronaut Harrison Schmitt stood tall among doubters saying that global warming was simply a ‘political tool’ and that many scientists had sold out their objectivity. Dr. John Christy of the Earth System Science Center at the University of Alabama continued to be an unbiased dissenter.Princeton’s Dr. William Happer appeared before Congress saying, “what used to be science has turned into a cult.”

Another prominent voice in weather and climate, William (Bill) Gray, Professor Emeritus of Colorado State University, said the American Meteorological Society was being hijacked by alarmists. Other scientific organizations including the American Physical Society (APS) and the American Chemical Society (ACS) saw rifts grow in their membership. It became clear as the year progressed that the so-called scientific ‘consensus’ was anything but.

Even the Environmental Protection Agency (EPA) saw its share of controversy. The Obama administration which had promised new transparency was accused of suppressing a report from its own employees that voiced doubt in the manmade climate change theory. Later in the year two of its lawyers released a YouTube video warning that proposed legislation would not accomplish anything.

Advocates that believed man was the dominating force in the climate continued to sound their warnings, often with outrageous claims that sometimes appeared laughable. James Hansen, as usual, was the most prominent of these as he took the final leap from scientist to activist not only in words but in actions as well. Not to be outdone, Dr. James Lovelock famously pronounced that 90% of the world’s population would be culled by 2100 due to climate change. President Obama joined in making false and extreme statements warning of ‘cataclysmic’ storms despite evidence to the contrary that no such thing is occurring.

Former vice president and Nobel Laureate Al Gore was as visible as ever throughout the year. He however continued to make a number of visible gaffes that did more to damage the cause than advance it. He wasforced to pull slides from a presentation he gave that were incorrect, the cover of his new book contained scientific impossibilities and at the UN Climate Change Conference in Copenhagen he misspoke on a number of issues.

In Congress, cap and trade legislation aimed at curbing carbon emissions seemed on the fast track but soon fell by the wayside. The Senate and the House of Representatives held many hearings on the topic with the House eventually passing legislation. The upper house however was hesitant to move on the issue for fear of facing a disgruntled electorate not willing to bear any additional financial burden and public opinion polls showing greater doubt. It now appears unlikely the issue will see a vote in the Senate until after the next election cycle.

November brought forth an event that would shake the very foundation of climate science. TheClimategate email scandal broke right before Thanksgiving when thousands of emails from some of the world’s top climate scientists were released on the Internet. The messages were not only embarrassing for those involved but proved to be more damning as they revealed collusion amongst scientists to withhold climate data, foil openness in the debate, silence dissenting opinions and modify data to fit their theories.

The mainstream media ignored the event for days and weeks but the Internet gave the story life and it soon turned into a major controversy. Investigations into the actions of the climate scientists have been launched and new revelations about the actions of those involved continue to be discovered.

Climategate’s effects cast a pall over the United Nations Climate Change Conference (COP15) in Copenhagen early in December. The Intergovernmental Panel on Climate Change (IPCC) had hoped the summit would yield a comprehensive climate change treaty. In the weeks leading up to the event, that seemed doubtful and soon it became an impossibility.

Not a day went by that scientists and politicians weren’t forced to address the email scandal and the doubts it had sewn into the public consciousness. Divisions amongst developed nations and poorer nations soon turned into insurmountable rifts and chasms. Richer nations demanded accountability for all nations while developing nations insisted on billions of dollars in financial aid.

President Barack Obama flew to Copenhagenin the closing days of the summit and many hoped he would be able to salvage the talks. The differences were too large though and theCopenhagen Accord that emerged had many saying it wasn’t worth the paper it was written on.

Arguably 2009 was one of the most eventful since the manmade climate change theory was first put forth. The year started with the science seemingly ‘settled’ and a ‘consensus’ pointing to man being the dominant influence on climate. In 12 short months however, the tide shifted. Scientific evidence to the contrary finally saw the light of day, cracks emerged amongst the so-called consensus and major events rattled the basis of what had been thought to be fact. The year has proven that the debate is not over nor is anything truly settled about anthropogenic global warming.

Great Green Wall of the Sahel




See my posting on the Fertilizer Tree. These guys do have the right idea.  A tree belt, however narrow, delineates a line and encourages work to strengthen the lands south of the lands.  In time these lands will prosper, and if also reforested with acacia that amazingly does not compete with ordinary crops, Then perhaps we will see a restoration of daily rains during part of the year.  In time we will see the line begin to move northward.

 

The management of the Sahel is common right across all of Africa in a band south of the Sahara.  Restoration of an Acacia agro base should permit the Sahara itself to be fully reclaimed over the centuries even if we do not introduce the Eden machine to harvest water from the atmosphere.  It certainly was fully vegetated during the Bronze Age when the goat was introduced.

 

This tells us that at least one government has gone out to make a dramatic gesture that gets everyone’s attention.  This is leadership and begins the process.  I do not think it is a false start at all because today the cell phone is plugging everyone in to what their neighbors are doing and most importantly if it is working.

 

 

Africa-wide "Great Green Wall" to Halt Sahara's Spread?

Christine Dell'Amore in Copenhagen
December 28, 2009



China built its famous Great Wall to keep out marauders. Now, millennia later, a "Great Green Wall" may rise in Africa to deter another, equally relentless invader: sand.
The proposed wall of trees would stretch from Senegal to Djibouti as part of a plan to thwart the southward spread of the Sahara, Senegalese officials said earlier this month at the UN's Copenhagen climate conference.
The trees are meant "to stop the advancement of the desert," Senegalese president and project leader Abdoulaye Wade told National Geographic News in Copenhagen.
In many central and West African countries surrounding the Sahara, climate change has slowed rainfall to a trickle, according to the UN's Intergovernmental Panel on Climate Change (IPCC).
Crops have died and soils have eroded—crippling local agriculture. If the trend continues, the UN forecasts that two-thirds of Africa's farmland may be swallowed by Saharan sands by 2025 (explore an interactiveSahara map).
Trees are almost always formidable foes against encroaching deserts, said Patrick Gonzalez of the University of California, Berkeley's Center for Forestry.
That's because stands of trees act as natural windbreaks against sandstorms, and their roots improve soil health—especially by preventing erosion.
But choosing the right tree species to populate the wall will be crucial to the project's success, Gonzalez said via email.
Similar tree-planting efforts by outside agencies have failed, he said, in part because they planted foreign species that soon perished in the harsh desert.
"We Have to Do What We Have to Do"
Nigerian President Olusegun Obasanjo first proposed the idea of a desert-blocking wall in 2005, and it was approved by the African Union in 2007.
All 11 countries that would house the Great Green Wall have pledged to help fund the project.
But the wall has been slow to break ground: Of the 4,350 miles (7,000 kilometers) it needs to cover, only about 326 miles (525 kilometers) have been planted so far, all within Senegal.
In Copenhagen, President Wade emphasized that he has made the wall a priority, and he has already asked scientists working on the project to choose species hardy enough to survive in arid conditions without maintenance.
"One thing the president has insisted is … we have to begin the work now, right now," added Ndiawar Djeng, advisor to the Senegalese environment minister.
"If other international committees follow us, that's OK. If not, we have to do what we have to do," Djeng told National Geographic News.
"It's in the interest of our local people."
Farming Boon
The lush channel through the desert would help farmers already displaced by drought—and may even stem the exodus of "environmental refugees," organizers say.
More than 70 percent of Africa's poor depends on farming, according to the IPCC.
But drought, desertification, and other climate-related disasters are forcing many farmers to abandon their lands, spurring a heavier flow of immigrants out of central and North Africa.
The 9.3-mile-wide (15-kilometer-wide) wall of trees would improve the surrounding, now-degraded soils, allowing farmers to again grow crops and more easily raise livestock in the region.
Senegal also plans to dig rainwater reservoirs along its portion of the wall—virtual lifesavers in a region where rain falls only three months out of the year, supporters say.
"France is helping us by bringing its soldiers, who are working with us planting trees and building reservoirs," President Wade added.
The gigantic tree barrier would also trap some atmospheric carbon dioxide, a potent greenhouse gas, and produce a refuge for native animals and plants.
Some of the trees themselves may become valuable crops.
The native acacia senegal tree, which is to be a staple plant in the Great Green Wall, produces gum arabic, a main ingredient in consumer products such as cosmetics and soft drinks.
Farmers could collect the sap and even sustainably harvest some of the wood to make tools or produce charcoal, Senegalese environment advisor Djeng said.
Local Know-How
But Senegal may do more for farmers by simply supporting age-old solutions to desertification, UC Berkeley's Gonzalez noted.
For example the ethnic groups of the Sahel—a swath of semi-arid savanna on the Sahara's southern border—have long been successful at reforesting their land using "natural regeneration."
In this method, farmers plant small native trees from seeds found in the region and raise the trees in agricultural fields protected from nibbling livestock, Gonzalez said.
"The Great Green Wall is less feasible than supporting and reinforcing local farmers and the practice of natural regeneration," he said.
What's more, planting trees alone will not stop the Sahara's spread, according to Matt Brown, senior conservation advisor for the Nature Conservancy's Africa program.
Instead, African governments need to find ways to protect existing vegetation and water sources from overuse, Brown said by email.
Overall, though, the Great Green Wall is an "extremely bold" undertaking, he said, and "sometimes thinking big is what is needed to draw attention to a problem."


Fertilizer Tree






I had already identified acacia trees as a prime plant in reforestation efforts throughout Africa, principally because of its ability to obviously prosper in dry land conditions.  After reading this, it obviously should be introduced worldwide.

 

Combine the trees with maize culture and bio char soil enhancement from the maize and in one generation we should have naturally fertile soils.  This work is showing us that folks are beginning to open their eyes and find working solutions for their worlds.

 

Acacia is a natural shade tree and planted properly will lower ground temperatures.  This also encourages rainfall and ground cover growth.  The startling revelation for me was that the leaves are shed at the beginning of the rainy season, effectively allowing a ground crop to emerge unimpeded.

 

I find this a bit hard to attribute to mere good fortune.   One wonders at the possibility of a deliberate breeding program a long time ago. 

 

The bottom line is that the entirety of the Sahel needs to be forested and farmed with this stuff.  Done properly, the Sahel will advance deep into the Sahara with almost no help because the tree cover will encourage the northward movement of rainfall.

 

"Fertilizer Tree" May Revive African Farmlands

Ochieng' Ogodo in Nairobi, Kenya
September 3, 2009
For one and a half decades, Johannes Mutisya, 54, a farmer in Kenya's Makueni district just east of Nairobi, has done what he could to eke out a living—but with little success.
He has bent wearily and scratched the dry, hardened earth, sprinkling a few maize or bean seeds and hoping for the best.

"These days we are only trying," Mutisya said, a distant look on his face.
"It is not like two decades ago and beyond, when people could be sure of bounty harvest after the rains."
Mutisya's situation is occurring across Africa, where farmlands are severely degraded and production is down.
African farmers on average apply only 10 percent of the soil nutrients, such as fertilizer, used in other parts of the world.
Coupled with effects of climate change, such as extreme droughts, the situation seems bleak.
But growing trees—especially acacia— on farms can improve the lot of some African farmers, said Dennis Garrity, who heads the Nairobi-based World Agroforestry Center.
Garrity spoke at the Second World Congress of Agroforestry held in Nairobi in August, which convened more than a thousand international experts to discuss the importance of growing trees on farms.
Nitrogen Fixer
The tall, long-lived acacia tree Faidherbia albida could serve as a free source of long-lasting and crop-boosting nitrogen, Garrity said.
A nitrogen fixer, the tree species could limit the use of polluting chemical fertilizers while also providing animal feed, construction material, and even medicine for farmers across sub-Saharan Africa.
"This is a fertilizer tree with reverse leaf phenology, which makes it become dormant and shed off its nitrogen-rich leaves during the early rainy season and at planting time when seeds need nitrogen," he said.
"And [then the tree] regrows the leaves at the beginning of the dry season, and thus does not compete with crops for light."
The tree species also acts as a windbreaker, provides wood for fuel and construction, and checks soil erosion by making the soil loose for water absorption during rainy season, Garrity added.
Acacia, iconic trees of the African landscape, are well adapted to a wide array of climates and soils, from the deserts to the humid tropics.
"Fertilizer Trees"
Scientists first observed farmers in Africa's Sahel region growing the trees in their sorghum and millet fields about 60 years ago.
Today the practice is still seen in Senegal, Mali, Burkina Faso, Niger, Chad, Sudan, and Ethiopia, and in parts of northern Ghana, northern Nigeria, and northern Cameroon. (See a map of Africa.)
In Zambia preliminary research has found that unfertilized maize yields in the vicinity of acacia trees averaged nearly three times those of crops grown nearby but beyond the trees' canopy.
Nobel Peace Prize laureate Wangari Maathai told the agroforestry conference that Africa must return to sustainable agriculture that embraces planting of "fertilizer trees" such as acacia.
"We have done great damage to the ecosystems through less sustainable agriculture practices like monoculture that has contributed to food insecurity in Africa," Maathai said.
"We need to encourage farmers to grow many food crops to reduce vulnerability of communities."
Acacia trees may also give small farmers benefits in the lucrative carbon-storage market, said Archim Steiner, executive director of the United Nations Environment Program (UNEP).
The World Agroforestry Center and UNEP are developing a standard method for measuring carbon storage on all types of landscapes, which could provide a basis for providing farmers with a financial incentive to increase tree cover on their farms.
Climate change talks scheduled later this year in Copenhagen will consider a new strategy that could include such a program.