Breakthrough: biochemists find method for bypassing aluminum toxicity effects in plants

A team of biochemists has devised a method for bypassing aluminum toxicity effects in plants. The breakthrough opens up new avenues for engineering aluminum-tolerant crop plants, benefiting agricultural production worldwide. Aluminum toxicity is a global agricultural problem severely limiting agricultural productivity in more than half of the world's arable land. The problem is especially severe in large parts of the developing world, where acid soils are predominant.

For many years, scientists have puzzled over how toxic levels of aluminum damage the growing root. The popular understanding is that aluminum binds to several targets in the root system, blocking cell division, damaging DNA, and ultimately interrupting plant growth.

Now, working on the model plant Arabidopsis, a team of scientists from the University of California, Riverside has determined that it is not aluminum toxicity that is directly responsible for inhibiting plant growth. The researchers identified a factor in plant cells, called AtATR, that functions as a built-in DNA surveillance system for alerting the plant of damage from excess aluminum and shutting down growth.

The researchers' experiments showed that AtATR can be manipulated to greatly enhance aluminum tolerance, resulting in plants whose roots can grow normally in soils that contain toxic levels of aluminum. Study results appear in the Oct. 14 issue of Current Biology.

Plants actively monitor aluminum-dependent damage through AtATR. But by breaking this assessment mechanism in a plant growing in soil with high aluminum content, we were able to stimulate plant growth again because the plant was no longer able to sense the damage aluminum caused. In other words, by bypassing this growth checkpoint, plants are not able to sense the effects of aluminum; they continue to grow even in an aluminum-toxic environment that is highly inhibitory to a normal Arabidopsis plant. - Paul Larsen, associate professor of biochemistry, lead author of the study

The research, which gives scientists new insights into how aluminum tolerance works in plants, offers a new strategy for engineering crop plants that can tolerate growth in aluminum-toxic environments, increasing crop production in areas that otherwise could not sustain agriculture

Dr. Larsen's work is a significant breakthrough in our understanding of how aluminum toxicity inhibits root growth. What he has shown, using an elegant combination of genetics, molecular biology and physiology, is that aluminum causes DNA damage in the growing root tip. The cells of this region have a mechanism to monitor this damage and shut down cell division and thus, root growth. - Leon Kochian, a professor of plant biology at Cornell University, not involved in the research

Larsen explained that a root tip has a "quiescent center" that houses stem cells – master cells, maintained throughout the life of the root, that develop into cell types and tissues. Aluminum toxicity results in the loss of these stem cells, and consequently cell division, bringing growth to a halt:
energy :: sustainability :: biomass :: bioenergy :: agriculture :: soil :: acidity :: aluminum toxicity :: developing world ::

"Knocking off AtATR's functioning maintains the quiescent center," said Larsen, who joined UCR's Department of Biochemistry in 2000. "In our study, we broke AtATR throughout the plant. But if we can break this factor only in the root tip, the plant will not sense aluminum's damage to the root. The root then continues to grow and we regain productivity."

The researchers' experiments involved introducing random mutations throughout the genome of Arabidopsis and screening for those roots that can grow in the presence of high levels of aluminum.

A silvery-white metal, aluminum is the most abundant metallic element in the Earth's crust. Never found in the metallic form in nature, it occurs instead in compounds. Next, Larsen's lab will work on identifying other factors in plants that detect DNA damage. His lab also plans to induce the AtATR mutation into crop plants such as tomato and corn to increase their aluminum tolerance.

Larsen was joined in the research by Megan A. Rounds, his graduate student. Grants from the National Science Foundation and the United States Department of Agriculture funded the five-year study.

UCR's Office of Technology Commercialization has applied for a patent on Larsen's discovery, and is looking for commercial partners interested in developing the technology.


Map: global distribution of acidic soils, where aluminum toxicity is a major problem. Acidic soils indicated in brigh and dark red tints. Source: FAO.

References:
Megan A. Rounds and Paul B. Larsen, "Aluminum-Dependent Root-Growth Inhibition in Arabidopsis Results from AtATR-Regulated Cell-Cycle Arrest", Current Biology, ahead of print, October 2, 2008.

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6 environmental research studies reveal critical health risks from petro-plastic

In a series of environmental research studies, scientists call for regulatory action to prevent dire health effects of man's exposure to petroleum based plastics. Exposure to Bisphenol A (BPA), phthalates and flame retardants (PBDEs) are strongly associated with adverse health effects on brain development and reproductive organs of humans and laboratory animals, the scientists found. A special section in the October 2008 issue of Environmental Research, titled "Plastic World", provides critical new research on these environmental contaminants and their adverse reproductive and behavioral effects.

Plastic products contain "endocrine disrupting chemicals" that can block the production of the male sex hormone testosterone (phthalates used in PVC plastic), mimic the action of the sex hormone estrogen (bisphenol A or BPA used in polycarbonate plastic), and interfere with thyroid hormone (brominated flame retardants or PBDEs used in many types of plastic).

Two articles report very similar changes in male reproductive organs in rats and in humans related to fetal exposure to phthalates. Two articles show that fetal exposure to BPA or PBDEs disrupts normal development of the brain and behavior in rats and mice. Two other articles provide data that these chemicals are massively contaminating the oceans and causing harm to aquatic wildlife (and here).

The other studies integrate new laboratory research with a broader view reflecting exposures to a variety of chemicals in plastic. These ubiquitous chemicals found in many plastics act independently and together to adversely affect human, animal and environmental health.

The articles show amongst others the massive contamination of the Pacific Ocean with plastic, and the amount of contamination has increased dramatically in recent years; animal brain structure, brain chemistry and behavioral effects from exposure to BPA and "phthalate syndrome" in rats' male offspring.

For the first time a series of articles will appear together that identify that billions of kilograms of a number of chemicals used in the manufacture of different types of plastic can leach out of plastic products and cause harm to the brain and reproductive system when exposure occurs during fetal life or prior to weaning. - Dr. Frederick vom Saal, Guest Editor of theme issue "Plastic World"

"Not only are these studies of scientific importance, they also contribute to the ongoing US congressional hearings involving the Food and Drug Administration," remarked Gert-Jan Geraeds, Publisher of Environmental Research. As such, "The Plastic World" has a broader societal impact and raises awareness of increasingly important environmental issues:
energy :: sustainability :: biomass :: bioplastic :: oil :: plastics :: toxicity :: ocean :: wildlife :: reproductive organs :: hormones :: brain development :: endocrine system organs ::

Environmental Research: A Multidisciplinary Journal of Environmental Sciences, Ecology, and Public Health publishes original reports describing studies of the toxic effects of environmental agents on humans and animals. The principal aims of the journal are to define the etiology of environmentally induced illness and to increase understanding of the mechanisms by which environmental agents cause disease.

Illustration: the male and female endocrine system.

References:
Frederick S. vom Saal, Stefano Parmigiani, Paola L. Palanza, Lorne G. Everett, Richard Ragaini, "The plastic world: Sources, amounts, ecological impacts and effects on development, reproduction, brain and behavior in aquatic and terrestrial animals and humans", Environmental Research, 108 (2008), pp. 127 - 130

Charles James Moore, "Synthetic polymers in the marine environment: A rapidly increasing, long-term threat", Environmental Research, 108 (2008), pp. 131 – 139

Jörg Oehlmann, Matthias Oetken, Ulrike Schulte-Oehlmann, "A critical evaluation of the environmental risk assessment for plasticizers in the freshwater environment in Europe, with special emphasis on bisphenol A and endocrine disruption", Environmental Research, 108 (2008), pp. 140 – 149

Paola Palanza, Laura Gioiosa, Frederick S. vom Saal, Stefano Parmigiani, "Effects of developmental exposure to bisphenol A on brain and behavior in mice", Environmental Research, 108 (2008), pp. 150 – 157

Chris E. Talsness, "Overview of toxicological aspects of polybrominated diphenyl ethers: A flame-retardant additive in several consumer products", Environmental Research, 108 (2008), pp. 158 – 167

Kembra L. Howdeshell, Cynthia V. Rider, Vickie S. Wilson, L. Earl Gray Jr., "Mechanisms of action of phthalate esters, individually and in combination, to induce abnormal reproductive development in male laboratory rats", Environmental Research, 108 (2008), pp. 168 – 176

Shanna H. Swan, "Environmental phthalate exposure in relation to reproductive outcomes and other health endpoints in humans", Environmental Research, 108 (2008), pp.

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Scientists call for sustainability framework for U.S. biofuels

In his State of the Union Address on January 23, 2007, President Bush stated that, in order to substantially lower foreign oil imports, "We must increase the supply of alternative fuels, by setting a mandatory fuels standard to require 35 billion gallons of renewable and alternative fuels in 2017."

This mandate coupled with a $1.01 ethanol refiner subsidy promised in the 2008 Farm Bill and a $45 subsidy per ton of biomass production for growers are putting energy needs ahead of environmental sustainability, according to an article in the October 3, 2008 issue of Science Magazine entitled "Sustainable Biofuels Redux".

Whether or not the benefits of biofuels are realized will depend on which, where and how these crops are grown, said Michelle Wander, University of Illinois soil scientist and one of the 23 authors of the article.

Even though there are many questions about biofuel sustainability that remain unanswered, we do know enough to move in the right direction right now by aggressively developing and implementing best management approaches in both the grain and cellulose-based systems. - Michelle Wander, Natural Resources and Environmental Sciences, University of Illinois

"Increasing the production of cellulosic materials to produce alternative fuels could have many social and environmental benefits, but it could also create problems for the environment and society that we haven't anticipated. In some instances we haven't had time to do the research while, in others, we have overlooked the obvious."

Wander said that the article cautions that although cellulosic feedstocks show promise by lessening the need for nitrogen fertilizer and other chemical inputs, the effects on biodiversity, water and soil could be negative if marginal land is claimed in order to prevent competition with food crops.

"We are going to have to tailor systems and crop choice to site conditions. For example, selection of miscanthus over switchgrass as a cellulosic bioenergy crop would produce more biomass and require less nitrogen but would require more water and would not feed wildlife."

The article goes on to state that globally, to produce an important amount of energy with biofuels requires a large amount of land:
sustainability :: biomass :: bioenergy :: biofuels :: biodiversity :: efficiency :: energy :: land use ::

This will change the landscape of the Earth, not just in the United States. "One of the least understood aspects of the biofuels roll out is how it will play out on the international stage. U.S. decisions can influence the magnitude and direction of land-use change elsewhere, and vice versa," Wander said.

It calls for research that assesses the energy yield and carbon implications as well as the full impact of biofuel production including implementation of land-management approaches and a better understanding of how policy and management practices will impact food access, food security, farmland, forests, watersheds and the globe.

The article concludes that "sustainable biofuel production systems could play a highly positive role in mitigating climate change, enhancing environmental quality, and strengthening the global economy, but it will take sound, science-based policy and additional research effort to make this so."

References:
G. Philip Robertson et al. "Sustainable Biofuels Redux", Science 3 October 2008: Vol. 322. no. 5898, pp. 49 - 50, DOI: 10.1126/science.1161525

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Xcel Energy to convert coal station into clean biomass power plant

Xcel Energy announces that it will submit an application to the Public Service Commission of Wisconsin (PSCW) to install pioneering gasification technology at the Bay Front Power Plant in Ashland, Wis. to allow it to generate electricity from biomass in all three operating units of this once coal-fired power plant. When complete, the Bay Front Power Plant will be the largest biomass-fueled power plant in the Midwest and one of the largest in the United States.

In 1979, the Bay Front Power Plant became the first investor-owned utility plant in the U.S. to burn waste wood to generate electricity. Since then, the two 23-megawatt biomass units of the plant have burned nearly four million tons of waste wood to make power. Bay Front is unique in that it has been retrofitted to be a “flex fuel” plant capable of burning multiple fuels in its three boilers.

Currently, only two of the three operating units use biomass as their primary fuel to generate electricity. This innovative project will convert the existing 30-megawatt coal-fired unit to biomass gasification technology allowing the plant to use 100 percent biomass in all three boilers. This is the first time biomass gasification technology will be used to convert a coal-fired boiler at an existing base-load power plant. The project is expected to cost $55-$70 million.

In this process, biomass (waste wood) reacts with a controlled amount of oxygen at high temperatures to create a gas mixture called synthetic gas (“syngas”) that is then used as a fuel in the boiler. By converting the biomass to gas, the resulting fuel is much cleaner and has far fewer emissions than coal.

This project continues our commitment to meet the needs of our customers in an environmentally responsible, sustainable manner. In addition to reducing carbon dioxide emissions, this project will drastically reduce other air emissions. - Mike Swenson, president and CEO, NSP-Wisconsin, an Xcel Energy company

When complete and operational, the project will reduce emissions of nitrogen oxides by 50 percent, sulfur dioxides by more than 85 percent and particulate matter by 90 percent. In addition, displacing coal with sustainably harvested biomass will also reduce net carbon dioxide emissions, contributing to the state of Wisconsin’s goals.

The biomass used at Bay Front comes primarily from waste wood from area forest harvest operations. Local independent contractors secure the waste wood and transport it to the plant where it is used to generate electricity. The plant currently uses just over 200,000 tons of waste wood each year. When the project is complete, the plant will use an additional 185,000-250,000 tons per year, and be able to generate enough renewable electricity to serve 40,000 homes:
energy :: sustainability :: biomass :: bioenergy :: gasification :: coal :: flex-fuel :: fuel switching :: Wisconsin ::

In 2006, Xcel Energy funded a study with the Energy Center of Wisconsin to investigate the amount of biomass that could be removed from Wisconsin's forests to support sustainable energy resources and any associated environmental impacts. The study concluded that area forests within a 50-mile radius of the Bay Front Power Plant could support additional biomass removal without adverse impacts to the local ecosystem. Dedicated biomass energy plantations could ultimately provide a portion of the plant’s increased biomass needs, with additional benefits from carbon sequestration.

Xcel Energy has been a long-time leader in providing renewable energy from local sources to the citizens of Wisconsin. This biomass initiative continues that tradition. - Michael Vickerman, executive director, RENEW Wisconsin.

This project will both lessen Wisconsin's reliance on imported fossil fuels and propel us closer to the renewable energy goals of Gov. Doyle's Task Force on Global Warming. - Mark Redsten, executive director, Clean Wisconsin

The Bay Front Power Plant is also an economic engine for communities in northern Wisconsin. Through its purchases of waste wood and related services, the plant has a $20 million annual economic impact on a six-county region around Ashland. Area officials expect that support to increase as the plant purchases more waste wood from area contractors.

This is exciting news for the City of Ashland. Xcel Energy is committing to convert and further upgrade the Bay Front Power Plant to run almost exclusively on biomass. This will help further our commitment to move toward renewable energy and our commitment to the sustainable goals of being an eco-municipality. Xcel Energy has been at the forefront providing upgrades to its generating and transmission facilities in Ashland and our surrounding region. These investments not only provide jobs and a huge economic impact to the Ashland area, they also add to the stability of our economy and our sources of electricity. - Ed Monroe, Mayor of Ashland

In 2005, Ashland became the second city in Wisconsin to become an “eco-municipality” and adopt the community development principles of sustainability. “Eco-municipality” communities strive to unite an economic and ecological balance in a common development strategy based on an area’s natural resources, environmental values, commercial and industrial structure, and local lifestyles.

Contingent upon final approval by the Xcel Energy Board of Directors, the company expects to file an application with the PSCW later this fall. Following all state regulatory approvals, engineering, design and construction work is expected to begin in 2010 and the unit could be operational in late 2012.

Xcel Energy is a major U.S. electricity and natural gas company with regulated operations in eight Western and Midwestern states. Xcel Energy provides a comprehensive portfolio of energy-related products and services to 3.3 million electricity customers and 1.8 million natural gas customers through its regulated operating companies. Company headquarters are located in Minneapolis.

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Nanotechnology and synthetic biology: poll shows U.S. public unaware of emerging technologies

An interesting poll finds that almost half of U.S. adults have never heard about nanotechnology, and nearly 9 in 10 Americans say they have heard just a little or nothing at all about the emerging field of synthetic biology, according to a new report released by the Project on Emerging Nanotechnologies (PEN) and Peter D. Hart Research. Both technologies involve manipulating matter at an incredibly small scale to achieve something new.

The broad lack of knowledge amongst the public means there is a lot of work to do for both policy makers and organisations involved in disseminating, vulgarizing and debating emerging technologies. The poll showed that informing citizens about these new fields markedly alters their perceptions of the potential benefits and risks of both technologies.

Scientists think both nanotechnology and synthetic biology will play an important role in some of the great issues of our time: solving energy scarcity, helping the race towards increased efficiency, the development of renewable fuels and tackling climate change, managing fresh water resources and minimizing environmental pollution, to name but a few. However, there is a range of uncertainties and risks involved in developing the technologies. Ethical questions surrounding the meaning of life and the use of its building blocks arise in the field of synthetic biology.

The new insight into limited public awareness of emerging technologies comes as a major leadership change is about to take hold in the United States. Public policy experts are concerned, regardless of party, that the federal government is behind the curve in engaging citizens on the potential benefits and risks posed by these technologies.

Early in the administration of the next president, scientists are expected to take the next major step toward the creation of synthetic forms of life. Yet the results from the first U.S. telephone poll about synthetic biology show that most adults have heard just a little or nothing at all about it. - David Rejeski, PEN Director

The poll findings are contained a report published today, titled "The American Public's Awareness Of And Perceptions About Potential Risks and Benefits of Nanotechnology & Synthetic Biology" (if this page requires a login and password, please use - login: synbio and password: advance.)

Synthetic biology is the use of advanced science and engineering to construct or re-design living organisms–like bacteria–so that they can carry out specific functions. This emerging technology is likely to develop rapidly in the coming years, much as nanotechnology did in the last decade. In the near future the first synthetic biology "blockbuster" drug is anticipated to hit the market—an affordable treatment for the 500 million people in the world suffering from malaria.

The poll found that about two-thirds of adults say they have heard nothing at all about synthetic biology, and only 2 percent say they have heard "a lot" about the new technology. Even with this very low level of awareness, a solid two-thirds of adults are willing to express an initial opinion on the potential benefits versus risks tradeoff of synthetic biology. This survey was informed by two focus groups conducted in August in suburban Baltimore. This is the first time—to the pollsters' knowledge—that synthetic biology has been the subject of a representative national telephone survey.

Informing citizens

Respondents were asked to evaluate the risks and benefits of synthetic biology and nanotechnology without receiving any information about it. For nanotechnology nearly half of adults were too unsure to make an initial assessment on the tradeoffs between risks and benefits. Of those who are willing to make a judgment, by three to one they think that benefits will outweigh risks (20%) as opposed to thinking risks will outweigh benefits (7%). The plurality, however, believe that risks and benefits will be about equal (25%). For synthetic biology, the respondents were slightly more likely to think that benefits will outweigh the risks (21%) than risks will outweigh the benefits (16%), while 29% believe that the risks and benefits will be equal (figure 2, click to enlarge):
energy :: sustainability :: biomass :: bioenergy :: biofuels :: efficiency :: climate change :: synthetic biology :: public awareness ::

The participants were then briefly introduced to the fields of nanotech and synbio, by means of a short text that summarizes key benefits and risks.

For nanotechnology, this text read as follows:

Nanotechnology is the ability to measure, see, predict, and make things on the extremely small scale of atoms and molecules. Materials created at the nanoscale are called nanomaterials, and they often can be made to exhibit very different physical, chemical, and biological properties than their normal-sized counterparts.

I would like to read you statements about the potential benefits and potential risks of nanotechnology and get your reaction.

The potential BENEFITS of nanotechnology include the use of nanomaterials in products to make them stronger, lighter, and more effective. Some examples are food containers that kill bacteria, stain-resistant clothing, high-performance sporting goods, faster, smaller computers, and more effective skin care products and sunscreens. Nanotechnology also has the potential to provide new and better ways to treat disease, clean up the environment, enhance national security, and provide cheaper energy.

While there has not been conclusive research on the potential RISKS of nanotechnology, there are concerns that some of the same properties that make nanomaterials useful might make them harmful. It is thought that some nanomaterials may be harmful to humans if they are breathed in and might cause harm to the environment. There also are concerns that invisible, nanotechnology-based monitoring devices could pose a threat to national security and personal privacy.

A similar introduction was read out for synthetic biology:

Synthetic biology is the use of advanced science and engineering to make or re-design living organisms, such as bacteria, so that they can carry out specific functions. Synthetic biology involves making new genetic code, also known as DNA, that does not already exist in nature.

I would like to read you statements about the potential benefits and potential risks of synthetic biology and get your reaction.

The potential BENEFITS of synthetic biology include developing new micro-organisms to treat disease, including cancer, more effectively and to create new and less expensive medications. It also could be used to make new organisms that could provide cheaper and cleaner sources of energy than today's oil-based fuels, and to detect and break down environmental pollutants in the soil, air, and water.

While the potential RISKS of synthetic biology are not known, there are concerns that man-made organisms might behave in unexpected and possibly harmful ways and that they could cause harm to the environment. There also are concerns that, if these organisms fall into the wrong hands, they could be used as weapons. Additionally, the ability to create artificial life has raised moral and ethical questions about how life is defined.

Respondents were then polled again as to their perception of risks and benefits of both technologies. Their view differed markedly from their initial assessment.

After hearing the information there is a 10-point increase in the proportion of adults who think that the benefits of nanotechnology will outweigh the risks (from 20% to 30%), there was a 16-point increase in the share who think that the risks will outweigh the benefits (from 7% to 23%), and a 13-point increase in the proportion who say the benefits and the risks will be equal. Just 9% remain unwilling to make a judgment

Upon hearing the statement about synthetic biology, 29% of adults said that the risks and benefits are equal (no change from the initial question), 28% believe benefits outweigh risks (a seven-point increase), and 35% think that risks outweigh benefits (a 19-point increase) (figure 3, click to enlarge).


A major industry forecasting firm determined that last year nanotech goods in the global marketplace totaled $147 billion. According to the poll, the level of U.S. public awareness about nanotechnology has not changed measurably since 2004 when Hart Research conducted the first poll on the topic on behalf of the PEN.

In 2007, the global market for goods incorporating nanotechnology totaled $147 billion. Lux Research projects that figure will grow to $3.1 trillion by 2015.

The Project on Emerging Nanotechnologies is an initiative launched by the Woodrow Wilson International Center for Scholars and The Pew Charitable Trusts in 2005. It is dedicated to helping business, government and the public anticipate and manage possible health and environmental implications of nanotechnology.

References:
Peter D. Hart Research Associates: "Awareness Of And Attitudes Toward Nanotechnology And Synthetic Biology - A Report Of Findings Based On A National Survey Among Adults" [*.pdf], Conducted On Behalf Of: Project On Emerging Nanotechnologies; The Woodrow Wilson International Center For Scholars - September 16, 2008

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Experiment demonstrates 110 years of sustainable agriculture

A plot of land on the campus of Auburn University shows that 110 years of sustainable farming practices can produce similar cotton crops to those using other methods. This oldest continuous cotton production experiment shows that winter legumes are as effective as nitrogen fertilizer in producing non-irrigated, 10-yr average cotton yields. The findings are important as we try to find less environmentally damaging farming methods that rely less on synthetic fertilizers.

In 1896, Professor J.F. Duggar at the Agricultural and Mechanical College of Alabama (now Auburn University) started an experiment to test his theories that sustainable cotton production was possible on Alabama soils if growers would use crop rotation and include winter legumes (clovers and/or vetch) to protect the soil from winter erosion.

Today, his experiment on the campus of Auburn University is the oldest, continuous cotton experiment in the world and the third oldest field crop experiment in the United States on the same site. The experiment, known as “the Old Rotation,” has continued with only slight modifications in treatments and was placed on the National Register of Historical Places in 1988.

Researchers at Auburn University and at USDA-Soil Dynamics Laboratory in Auburn, AL, have prepared the first ever comprehensive research publication covering the entire 110-yr history of this experiment. It was published in the September-October issue of Agronomy Journal, and provides insight into issues both past and present that effect sustainable crop production in the South.

The thirteen plots in the Old Rotation include (i) continuous cotton, (ii) a 2-yr rotation of cotton with corn, and (iii) a 3-year rotation of cotton-corn-wheat-soybean. These crop rotations include treatments with and without winter legumes (usually crimson clover and/or vetch) and with and without fertilizer nitrogen.

After more than 110 years, the Old Rotation continues to document the long-term effects of crop rotation and winter legumes on cotton production in the Deep South (graph, click to enlarge). It provides growers, students, and faculty with a living demonstration of fundamental agronomic practices that result in sustainable crop production. Long-term yields indicate that winter legumes are as effective as nitrogen fertilizer in producing non-irrigated, 10-yr average cotton yields of 1,100 pounds lint per acre. Winter legumes and crop rotations contribute to increased soil organic matter. Higher soil organic matter results in higher crop yields:
energy ::biomass :: bioenergy :: agriculture :: crop rotation :: nitrogen :: fertilizer :: soil organic matter :: sustainability ::

In 1997, the Old Rotation entered a new era of agricultural production where boll weevil eradication, genetically modified crops, and conservation tillage almost eliminated the need for the plow and pesticides.

In 2003, irrigation was added to half of each plot. Yields of cotton, corn, wheat and soybean continue to increase far beyond the yields of Professor Duggar’s generation.

Since initiating conservation tillage practices in 1997, all-time, non-irrigated record yields have been made on all the crops grown on the Old Rotation: 1,710 pounds cotton lint per acre in 2006, 95 bushels wheat per acre in 2001, 236 bushels corn per acre in 1999, and 67 bushels of double-cropped soybean per acre in 1997 after wheat.

Figure: Annual cotton lint yields for the no-N and no-legume treatment (Plot 6), the continuous cotton with only legume N treatment (Plot 8), and the 2-yr rotation + N treatment (Plots 5 and 9).

References:
Charles C. Mitchella, Dennis P. Delaneya and Kipling S. Balkcomb, "A Historical Summary of Alabama's Old Rotation (circa 1896): The World's Oldest, Continuous Cotton Experiment", Agronomy Journal 100:1493-1498, 8 September 2008, DOI: 10.2134/agronj2007.0395

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Biochar "one of the only ways to remove CO2 from the atmosphere"

Cornell University's Professor Johannes Lehmann explains that biochar -- sequestering carbon in soils -- is one of the only low-cost ways to remove CO2 from the atmosphere. The expert in soil fertility management and soil biogeochemistry calls for the launch of pilot projects that will allow us to study the real potential for scaling up the technique. Lehmann also warns that the biochar community must avoid making the mistakes shown in other renewable energy sectors.

There are very few alternatives for removing CO2 from the atmosphere. There is the idea to capture carbon from biomass power plants and to geosequester it. But geosequestration is expected to be costly and would take at least a decade or more to become technically feasible.

Other 'geo-engineering' methods to capture atmospheric CO2 or to counter climate change in a strong way, are all either very risky or extremely costly. The concept of introducing sulphur particles into the stratosphere so as to emulate the effect of the cooling blanket generated by a massive volcanic eruption, has been dismissed because the acid rain that would result from it is a serious threat to agriculture and fresh water supplies. It would also destroy the ozone layer. Iron-seeding the oceans so as to induce algae blooms has been rejected by marine ecologists and the international community: the effects of the intervention on marine biodiversity are unknown. Launching billions of tiny mirrors into space so that they form a cloud that can reflect sunlight back, away from Earth, is one of the most costly options. Finally, building large oceangoing vessels which spew salt particles into clouds so as to make them more reflective has some technical barriers to overcome.

One lower-risk strategy to capture CO2 is to erect plenty of 'synthetic trees', which withdraw the greenhouse gas from the air and store it deep into the ground. However, the method is not only very costly, it also doesn't overcome the objections raised against geosequestration.

In light of this list of difficult options, biochar seems to be the most elegant, low-cost and safe strategy. Plants are used as natural CO2 sponges. Once they have trapped the climate-destructive gas, man transforms the biomass into a stable form: biochar. This carbon-rich material is then sequestered into problem soils (like nutrient-poor tropical soils), where it has been found that adding char can improve the fertility of these soils. The char can stay locked up in the soils for very significant periods of time.
energy :: sustainability :: biomass :: bioenergy :: biochar :: atmosphere :: soil carbon sequestration :: geosequestration :: geo-engineering ::

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