Sustainable Horticulture

Show Me the Research – Volcanoes & Monsanto

Posted by sustainable_hort on April 27, 2010  |  1 Comment

Dear Readers…Sorry about the long break between posts, but farming requires one to take advantage of weather breaks…we finally had a break from several weeks of rain, tilling and planting had to get done.

But, I am back at the desk and this is the first of several posts that will go up over the next few days. The first section here is not really research but I do want to point out actual, current phenomenon that relate to this theory of sustainability. These entries are clarifying examples of why we need, and may be forced, to do things differently when it comes growing and consuming food.

Gaia Gets Back or Free Fertilizer?
First, the Iceland volcano situation. I started college many decades ago in geology and it remains a reference point for me when I look at the environment, agriculture, soils and soil fertility. Volcanic action may be part of a natural cycle of nutrients.

In fact, this is a key aspect of the theory of “paramagnetism.” Work by Carey Reams, and covered in the book “Paramagnetism,” by Dr. Philip S. Callahan, discuss this idea. It reduces much of soil nutrition into physics, the transfer of electrical energy at the molecular level feeding growth. This is why we see glacial dust and worm castings being sold as soil amendments. Rocks feed the soil organisms that break them down so the plant roots can absorb them as nutrients, especially the many minor elements.

When Mt. Saint Helens exploded and dumped a layer of ash over central Washington, it was, at first, a huge nuisance. But, within a few years, growers in the rich, agricultural region noticed their crops were doing fine, in some cases, better, since the eruption. The mountain had brought up a rich mixture of raw nutrients, and broadcast them over a wide region. It turned out to be free fertilizer!

But I had not thought of volcanic activity being the problem it became. Not only can an extended eruption play havoc with the transportation, affect economies and public health, but it could lead drastic climate change. One European climate expert said it could lead to extended, colder winters and reduced crop production for several years. Luckily this specific event seems to be settling down, but I don’t want to think where it could send the fragile world economy if it continued.

Yet, it also seemed almost a practice run of what would take place, over several decades, if there does become an oil/natural gas shortage. I mentionedThe Long Emergency several posts ago and have continued to re-read it. James Kunstler’s chapter on banking, investing and our financial system was probably written in 2004. His predictions were dead-on for what finally happened in 2008. You tend to listen those whose predictions start ringing true, so again, this book deserves your time. Since it is older book, I am sure it is available in many libraries or used. Check with Powell’s Bookstore online at www.powells.com.

As I mentioned, the eruption actually, in the long run of a few years, had a positive effect by providing a fresh, dusting of rock that used in the complex soil microbiology as food. So, let’s not hate volcanoes.

Monsanto Products Questioned
This week two articles appeared concerning Monsanto’s products, one an herbicide, the other a transgenic crop.

First, here in Oregon, we are following a regional alfalfa grower who has forced the company all the way to the Supreme Court today (April 27). His claim is that Monsanto’s transgenic alfalfa crossed with his crop, which then limited where his alfalfa can be sold. The article in the Oregonian points out the existing rules for approving this crop for general release were not even followed.

Then, another report on recent research showed that the “Round-Up resistance” is spreading to other plants, many which are common weeds. Won’t that eventually defeat the strategy and require another new herbicide to be developed? I guess Monsanto wins either way, but weed control can be simpler and weed growth greatly reduced just by having healthy soil. Believe it or not, weeds tend to grow in poorer soils and can be indicative of specific nutritional problems. More on that in a later post.

A related research story from AgCanada.com reported that scientists at the Saskatchewan Ministry of Agriculture Crop Protection Lab confirmed herbicide carry-over in ag soils. It was at levels that damaged the following sensitive crop. This is another reason for planting fields with certain cover crops that remove the negative compounds so other following crops are not harmed. And another reason to revisit how we control weeds, again looking at healthier soils.

And then, the other night, I stumbled across a 2008 documentary on Monsanto, called “Monsanto,” on the Sundance Channel. I knew much of the history, having followed the company for years and having read many well-researched commentaries. It was clear that the company focuses on stockholder demands. This drives it to take what are interesting technologies, combine them with rigid market agreements, and twist it into a rather arrogant sales strategy. Much of genetic engineering may be fine, but let’s just take one step back and study it more.

But, actually, my main concern is Monsanto’s deliberate, and brilliant, plan to corner the “seed” market. I am not just talking about Round-Up Ready soybeans, but a much, much wider net the company has thrown over the entire seed industry. The company has bought dozens of smaller seed companies over the past decade. Once they “own” all the genetic material that creates the annual food cornucopia, they can slowly (or not so slowly) ratchet up prices and demand the growers not save seed from “their” crops. The documentary includes several instances of just how far Monsanto will go to harass growers that don’t use their seed.

Seeds are literally the transference of life. Groups like Seed Savers have formed networks so there will be a genetic base of common vegetables and other food plants readily available to gardeners. It is an effort worth supporting. It is an effort that is part of making sure we can feed ourselves.

Enough for now…see you soon.

Trees for CO2 Sequestration?

Posted by sustainable_hort on April 14, 2010  |  No Comments

(This is the first part of a two-part post on trees and CO2 sequestration, which looks at whether trees actually play a positive role. The second part will discuss the actual trees we should be using for this perceived benefit)

Trees can play an important, positive role in helping control the amount of carbon dioxide (CO2) in the atmosphere by absorbing that key greenhouse gas. The process, called “sequestration,” uses a tree’s photosynthesis to convert the problematic greenhouse gas to cellulose and oxygen.

As this concept has become more widely accepted and, as researchers continue to document trees’ benefits, it may expand market for some nursery crops. But, is all this excitement warranted, or do some recent questions contradict the enthusiasm?

What We Need to Know
The crucial questions at this stage become “does sequestration really work,” and if so, “which trees are most efficient at sequestration?” Research continues to delve into varietal and climate issues that affect how well a specific tree will capture CO2.

“We can certainly argue that trees, when they absorb CO2, buy us a period of sequestration,” said David Nowak, researcher at SUNY-CESF, Syracuse, New York.

But, Nowak, who has lead several major sequestration studies, points out there are many variables that need to be studied, including climate effects, tree species and age, and even the general maintenance issues.

“These all can impact the effectiveness of a tree to sequester CO2,” he said.

Other research has pointed out some distinct differences based on climate. In fact, recent computer models are even speculating that non-tropical trees might even increase planet temperatures.

But, planting trees in [any] climate is better than not. So, how does it work and what does research indicate as the best options for using trees to reduce atmospheric CO2?

What is Sequestration?…Removal of Air Pollutants
Air pollution can be reduced dramatically when plants take up CO2 and many airborne particles through their leaf stomata. Some other gases are removed by the plant leaf and stem surfaces. Gases absorbed by the plant stomata later diffuse into intercellular spaces. They then are absorbed and react with water films to form acids, or they react with inner-leaf surfaces. Some particles can be absorbed into the tree, though most particles that are intercepted are retained on the plant surface.

Some polluting particles may return to the air during transpiration or be washed off by rain. Later, the leaf and twigs may drop off the to the ground and start to decompose. This also releases some of the CO2 back, which offsets some of the early gains. Consequently, vegetation remains only a temporary site for retaining many atmospheric particles.

Benefits of Trees
Plant-It 2020 uses a ‘scientific estimate’ to develop the following statistics based upon the tree species, soil conditions and tree-planting methodology,

Their research indicated that 600 trees in the tropics would fill one acre, which could sequester up to 15 tons of CO2 annually. Other statistics include 40 trees (common varieties) will sequester one ton of CO2 each year; and that one million trees covering 1,667 acres could capture 25,000 tons of CO2 annually.

Research in major metropolitan areas showed the urban forests could have an impact. It was reported by David J. Nowak in “The Effects of Urban Trees on Air Quality” showed that in 1994, trees in New York City removed an estimated 1,821 metric tons (t) of air pollution at an estimated value to society of $9.5 million.

His research showed that while New York’s urban forests removed pollution more than Atlanta’s (1,196 t; $6.5 million) and Baltimore (499 t; $2.7 million), but pollution removal per square meter of canopy cover was similar among these cities (New York: 13.7g/m2/yr; Baltimore: 12.2 g/m2/yr; Atlanta: 10.6 g/m2/yr). These standardized pollution removal rates differ among cities according to the amount of air pollution, length of in-leaf season, precipitation, and other meteorological variables. Nowak’s work noted that large healthy trees (greater than 77 cm) annually remove about 70 times more air pollution (1.4 kg/yr) than small healthy trees (less than 8 cm in diameter) at 0.02 kg/yr.

His 2002 work matched earlier research regarding total CO2 sequestered within the US. Total carbon storage by urban trees in the coterminous United States is estimated at 700 million tons. These data correspond with previous analyses that estimated national carbon storage by urban trees as between 350 and 750 million tons and between 600 and 900 million tons. Carbon storage by urban trees nationally is only 4.4% of the estimated 15,900 million tons stored in trees in USA non-urban forest ecosystems. The estimated carbon storage by urban trees in USA is equivalent to the amount of carbon emitted from USA population in about 5.5 months based on average per capita emission rates.

The research reported that “urban forests in the north central, northeast, south central and southeast regions of the USA store and sequester the most carbon, with average carbon storage per hectare greatest in southeast, north central, northeast and Pacific northwest regions, respectively. The national average urban forest carbon storage density is 25.1 t/ha, compared with 53.5 t/ha in forest stands.”

He felt this data could be used to help assess the actual and potential role of urban forests in reducing atmospheric carbon dioxide, a dominant greenhouse gas.

Nowak’s research report stated the following:
“Air quality improvement in New York City due to pollution removal by trees during daytime of the in-leaf season averaged 0.47% for particulate matter, 0.45% for ozone, 0.43% for sulfur dioxide, 0.30% for nitrogen dioxide, and 0.002% for carbon monoxide. Air quality improves with 2 increased percent tree cover and decreased mixing-layer heights. In urban areas with 100% tree cover (i.e., contiguous forest stands), short-term improvements in air quality (one hour) from pollution removal by trees were as high as 15% for ozone, 14% for sulfur dioxide, 13% for particulate matter, 8% for nitrogen dioxide, and 0.05% for carbon monoxide.”

Meanwhile, www.plantit2020.org, has summarized recent forestry science studies in carbon sequestration related to trees, including the following:

The U.S. Forest Service estimates that all the forests in the United States combined sequestered a net of approximately 309 million tons of carbon per year from 1952 to 1992, offsetting approximately 25% of U.S. human-caused emissions of carbon during that period.

The US Forest Service also feels that large diameter; long-lived, leafy trees are more beneficial in regards to carbon sequestration. For example, they point to the fact that Atlanta’s 9 million-plus (mostly mature, broad-leafed) trees absorb about twice as much as Calgary, Canada nearly 12 million trees (many conifers).

They also noted that tree species is a strong determining factor regarding carbon sequestration, which vary by species in their rate of storing carbon, though research is still needed.
But, as a counter action, trees also vary in how many and how much harmful volatile organic compounds (VOC’s) they emit. One common example is isoprene, which produces the greenhouse gas ozone.

So, the best tree species is one that rapidly sequesters carbon but does not register high outputs of VOC’s. Long-lived trees (those living more than 50 years) are preferred by the Forest Service for carbon sequestration as dead trees rot – releasing all of the carbon that has been stored. US Forest Service recommends the following species for the United States…American basswood, dogwood, Eastern white pine, Eastern red cedar, gray birch, red maple and river birch.

Nowak does point out that the placement of trees actually has more impact that sequestration.
“The bigger impact comes from planting a tree in the proper location where it can provide cooling for buildings,” he said. “Just by preventing the added CO2 being emitted during air conditioning, trees can have four times the impact they have in sequestration.”

So, there are many functions to consider to maximize a tree’s impact on the environment, he cautioned.

Tropical Versus Temperate Zones
Another study, lead by Lawrence Livermore National Lab, indicated that trees planted closer to the equator sequester more carbon than those planted far to the North. Why this might have happened is still unclear. Some expert speculated that Southern tree species are often larger, long-lived, leafy trees compared to northern species.

Their computer models seem to confirm this observation. They built a model to determine the impact on temperatures forests have in different parts of the planet.

They focused on three key factors in their analysis:
• Forests can cool the planet by absorbing the greenhouse gas carbon dioxide during photosynthesis.
• They can also cool the planet by evaporating water to the atmosphere and increasing cloudiness; a deck of white clouds reflects incoming solar radiation straight back out into space.
• But, trees might also have a warming effect. They are dark colored, absorb sunlight and hold heat near ground level

“Our study shows that tropical forests are very beneficial to the climate because they take up carbon and increase cloudiness, which in turn helps cool the planet,” explained Dr. Bala, an author on the Livermore study.

So, the further you move from the equator, the more these gains are eroded she stated. The team’s modeling predicts trees planted in mid- and high-latitude locations could cause a net warming of a few degrees within a hundred years.

“The darkening of the surface by new forest canopies in the high-latitude boreal regions allows absorption of more sunlight that warm the surface,” Dr Baal said.

Counter Views
But, despite the general excitement over planting trees, no, literally planting forests as a solution to global warming, has hit some speed bumps recently.

In addition to the Livermore computer model concerns, two other recent papers in the scientific literature raised questions about the benefits of terrestrial carbon sinks. One paper, by Frank Keppler, Max Planck Institute, discovered that plants emit significant amounts of methane, which is a potent greenhouse gas, which traps heat much more efficiently than CO2.

Another study, by Robert Jackson, Duke University, found that plantations could reduce stream flow and increase salinization of soils to a greater extent than previously recognized. It looked at existing conversions and showed that the growing trees had larger water demands than crops or pastures “dramatically decreased stream flow within a few years of planting,” the authors wrote.

They also found that water use within existing tree plantations of all ages resulted in average stream flow reductions of 38 percent. Losses increased as the trees age, and “13 percent of streams dried up completely for at least one year,” the study said.

Overall, the tree farming used about 20 percent more rainwater, the study estimated. So, additional tree planting for carbon mitigation could have large impacts on nation’s water resources. This is ore of an issue in nations that net less than 30 percent of their total annual supplies of fresh water from rain, the authors predicted.

This has lead to experts some questioning the overall tree planting strategy, but others view this speculation as overblown.
Nowak also cautioned that urban tree management practices could diminish the net effects of urban trees on atmospheric C02. Activities used to maintain vegetation structure and health (e.g. from chain saws, trucks, chippers, etc.) emit carbon via fossil fuel combustion. Thus, too much maintenance could cause urban forest ecosystems to become net emitters of carbon unless secondary carbon reductions (e.g. energy conservation) or limiting of decomposition via long term carbon storage (e.g. wood products, landfills) can be accomplished to offset the maintenance carbon emissions

“Carbon released through tree management activities needs to be accounted for to calculate the net effect of urban forestry on atmospheric carbon dioxide,” he said.

He argues that unless there are secondary carbon reductions (e.g., energy conservation) or limiting of decomposition via long-term carbon storage (e.g., wood products, landfills), urban forests lose much of the sequestration gains. This, in turn, affects the species composition and tree maintenance activities chosen for an urban forest.

Some Conclusions
So, where does all this leave with trees and their effects on CO2 sequestration?

To maximize the net benefits of urban forestry on atmospheric carbon dioxide, Nowak wrote that urban forest managers should focus on the following:
• Planting long-lived, low-maintenance, moderate to fast-growing species that are large at maturity and matched to site conditions;
• Using maintenance activities that increase tree survival and longevity;
• Minimizing fossil-fuel use related to management and maintenance activities;
• Using wood from removed trees to delay decomposition or decrease the need for energy from fossil-fuel-based power plants (e.g., develop long term wood products; burn wood to heat residences); and
• Planting trees in energy-conserving locations.

This was summarized clearly by Greg McPherson in a Arbor Age article “Urban Tree Planting and Greenhouse Gas Reductions.”

He wrote that…”The climate benefits of trees in mid-latitude cities are not an illusion, although they certainly feel good. Reductions in atmospheric carbon dioxide are achieved directly through sequestration and indirectly through emission reductions. Still, planting trees in cities should not be touted as a panacea to global warming. It is one of many complementary bridging strategies, and it is one that can be implemented immediately. Moreover, tree planting projects provide myriad other social, environmental, and economic benefits that make communities better places to live.”

Thus, while CO2 absorption can be positive, putting the right tree in the right place remains critical to optimizing its benefits and minimizing conflicts with other aspects of the urban infrastructure.

Next part…coming soon. We will look at where trees work best, which trees might be the best, and include a long list of references on this topic. See you soon.

Show Me the Research

Posted by sustainable_hort on April 4, 2010  |  No Comments

It seems that for decades the conventional agricultural community responded to organic claims with “ show me the scientific research.” That, in fact, was what led me back to Oregon State University many decades ago. I was growing food organically but did not feel I had my science in order. But, their response was valid in a sense. There was not recent research that could back it up. But, if one ventured back to before World War II, there was a body of work (see the earlier post titled Soil Health and Organic Fertilizers for a short list of key sources) that seemed to support organic agriculture strategies.

Time limits me to maybe one long article a week on this blog. But, as I do research for my writing, I come across many interesting and pertinent stories, articles, studies, and books. It is information I sense has a place on this blog. So, at least a few times a month, I will post “Show Me the Research” notes. As a visitor, this will help you identify the more in-depth pieces, from simpler informational pieces. Again, I want to thank everyone for their positive comments.
So, for the first “Show Me the Research.”

First, some more book recommendations. The first is the The Long Emergency, written by James Howard Kunstler. Though is was first published five years ago, its content and message remain topical, maybe even more so today. I first read it years ago, but recently found a used copy, bought it, and have been re-reading parts of it. It is not a diatribe against global warming, though it includes the topic as part of an overall discussion of our economy’s dangerous reliance on petroleum for much of our lifestyle, energy, food and industry. Kunstler clearly shows that petroleum is at the base of many products, and as the world economy moves to duplicate US and European models, it will become a limiting factor. His best-case scenario seems to be that everything will cost more, much more. The alternatives are less comfortable to imagine. Many other books cover some of the same ground, but none are as complete or so soundly based on solid research.

The other work is much newer. The End of Overeating by David A. Kessler, MD, jumps into the current discussion on diet with a slightly different approach. Kessler looks at how and why we eat, clearly showing how food manufacturers manipulate “sugar, fat and salt” to over stimulate our appetites. These “manipulations” work surprisingly well, leading us to both overeat and consume foods that are not as healthy. The dozens of books published on diet topics generally tell us what to eat, but don’t explain why it so difficult to control our eating. A fascinating work by the former commissioner of the US Food and Drug Administration who successfully fought the tobacco industry. Now, with this book, takes a lead role in giving us tools to change what Michael Pollen describes as “the catastrophe that is the modern American diet.” Read it and then eat.

• Herbicide Resistance Identified…The Nebraska Rural Radio Association reported that “Kansas State University (KSU) scientists have completed long-term evaluations of a limited number of independent kochia (Kochia scoparia) populations on privately-owned land in western Kansas that are now confirmed to be glyphosate (Round-Up)-resistant.”

In the western U.S. and Canada, Kochia, or “fireweed,” is often found in arid and semi-arid croplands, rangelands, pastures, and non-agricultural sites. Very adaptable, Kochia even grows on saline and alkaline soils. It a serious “weed” and control will now be more complex and expensive. This resistance developed naturally, possibly due to growers using lower rates that left a few tougher plants, not through genetic modification. But, it points to why there is concern about this happening as “Round-Up resistant” crops are planted. I am not saying that genetic modification is all bad, but this type of natural resistance seems to require science to study this closely. This type of manipulation could actually lead to faster development of resistance in the environment.

• Since I also co-own an organic produce farm, I like to see people eat more vegetables. Now more proof fresh, nutritional produce is important…worth more of your food dollar.

1) Carolyn Lister, research leader at the New Zealand Institute for Plant & Food Research told www.newkerala.com that while fruit has tended to attract the greatest attention and the ‘super food’ label, there is a body of clinical research underlining the significant health benefits of vegetables in both raw and cooked form, with broccoli along with the other brassicas, tomatoes, onions and other alliums proving to be the vegetables with the strongest scientific evidence behind them.

“This evidence varies from in vitro studies through to human feeding studies,” she claims. “Although there is considerable variation in the results of different studies…looking at the summation of results, there is quite strong evidence for benefits to human health of a number of vegetables.”

Lister is a key scientists with the Vital Vegetables program, working to develop vegetables with increased health benefits, using traditional breeding techniques.

This is similar to a new study by researchers at the University of Alabama at Birmingham has released a study indicating that anti-oxidants – plant-based substances in foods such as broccoli, berries, tomatoes, spinach, carrots, grapes and garlic, are a key in preventing the flu.

“The recent outbreak of H1N1 influenza and the rapid spread of this strain across the world highlights the need to better understand how this virus damages the lungs and to find new treatments. Additionally, our research shows that anti-oxidants may prove beneficial in the treatment of flu,” said study co-author Sadis Matalon.

2) Other work shows “flavonols” might reduce women’s stroke risk. This has been reported by Dutch researchers in the Journal of Nutrition.

“We showed for the first time, to our knowledge, that flavonol intake was inversely associated with stroke incidence,” wrote the researchers. “We conclude that evidence is accumulating that flavonol intake is inversely related to different cardiovascular disease outcomes,” they added.

Despite reporting a potential risk reducing effect of compounds from tea, onions, apples, and broccoli the results should be “interpreted with caution.” The study followed over 110,000 people, noting higher consumption of flavonols, mostly tea in the Dutch population; and from tea, onions, apples, and broccoli in US studies, accounted for the reduction in stroke risk.

Flavonols are “flavonoids,” which also include anthocyanins (berries), isoflavones (soy), flavones (parsley and thyme), flavanones (citrus), flavonols (tea) and proanthocyanidins (berries, wine and chocolate.) Boy I like those last two! An editorial in the American Journal of Clinical Nutrition (July 2008, Vol. 88, pp. 12-13), echoed that statement, saying the “contribution of flavonones to a person’s antioxidant capacity was significant.”

• Finally, good news for those of us guys who are night people and require multiple cups of coffee to survive the morning.

A recent US study indicates that coffee may boost prostate health. It said “increased intake of coffee may reduce the risk of lethal and advanced prostate cancers by 60 per cent.” The study followed almost 50,000 men for over four years and found that males with the highest intake of coffee had significantly lower risks of aggressive prostrate cancer. The study is said to be the first study of its kind to look at both overall risk of prostate cancer and risk of localized, advanced and lethal disease.

“Coffee has effects on insulin and glucose metabolism as well as sex hormone levels, all of which play a role in prostate cancer. It was plausible that there may be an association between coffee and prostate cancer,” said Kathryn Wilson, PhD, from Harvard Medical School and the Harvard School of Public Health. The researchers presented their findings at the American Association for Cancer Research Frontiers in Cancer Prevention Research Conference late last year.

Well…that’s enough for one reading. See you next week with the second “Show Me the Research.”