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Researchers Improve Soil Carbon Cycling Models

Big Crop Damage Oak Ridge National Laboratory’s new carbon cycling model could help scientists understand the role of soil in climate change by tracking the microbial processes that break down carbon-rich materials. (Credit: Image courtesy of Oak Ridge National Laboratory)

ScienceDaily (Aug. 16, 2012) — A new carbon cycling model developed at the U.S. Department of Energy's (DOE) Oak Ridge National Laboratory better accounts for the carbon dioxide-releasing activity of microbes in the ground, improving scientists' understanding of the role soil will play in future climate change.

Predicting climate change depends heavily on the cycling of carbon dioxide, which is found in four main reservoirs: the atmosphere, biosphere, oceans and soil. ORNL's model was designed to replace traditional soil carbon cycling models.
Soil is a big reservoir of carbon," said co-author Melanie Mayes of ORNL's Environmental Sciences Division. And most of the soil carbon cycling models in use today are so vastly simplified that they ignore the fact that decomposition is actually performed by microbes.
In a paper published in Ecological Applications, the journal of the Ecological Society of America, ORNL researchers integrated data from scientific literature on carbon degradation in soil to form the Microbial-Enzyme-mediated Decomposition, or MEND, model that improves upon previous models.
"Our MEND model does a better job of representing the mechanisms of soil carbon decomposition than existing models," Mayes said.
ORNL's comprehensive model accounts for how the different forms of carbon in soil, or ;pools, react with extracellular enzymes excreted into the soil by microbes, allowing scientists to understand how quickly carbon is moving through soils.
The model simulates the carbon cycle, beginning after a decaying plant or animal releases carbon-rich materials into the soil. The organic material is degraded by enzymatic reactions, releasing dissolved carbon molecules that can be absorbed by microbes for growth or metabolism. These processes ultimately result in the release of carbon dioxide.

ORNL's MEND model is the first model able to track degradation by accounting for most of the relevant processes and by estimating the parameters based on a comprehensive literature review. This model, which is based on the physiological functions of microbes, accounts for how temperature affects the ability of microbes to emit carbon dioxide. Soil can either store or release carbon depending on how rapidly carbon-rich materials in the soil are decomposed.

"What we think will happen is that as temperature goes up, microbial physiology will change, altering their ability to break down carbon chains and release carbon dioxide into the atmosphere," Mayes said. "If our models don't account for this process, then our ability to predict future climate change will be less realistic."

For the next six to eight months, ORNL's team will run laboratory-scale experiments to ensure that the MEND model accurately represents the decomposition of carbon compounds in soils. Eventually, team members hope to incorporate their model into the publicly available supercomputing program called the Community Land Model, a module used in the Community Earth System Model that helps researchers predict future climate change.
The study was supported by ORNL's Laboratory Directed Research and Development program, and model development will continue to be funded by DOE's Office of Science.
Co-authors of the paper include Mayes and ORNL's Gangsheng Wang and Wilfred Post.

Source: Science Daily

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Robots to tend lettuce fields

Robots to tend lettuce fieldsThis graphic shows a Lettuce Bot being pulled through a field as it thins and weeds with the aid of a computer-vision algorithm.

Robots built and programmed to perform tedious, back-breaking tasks such as thinning and weeding lettuce fields could make labor shortages on the farm a distant nightmare for industrial agricultural operations of tomorrow.

Such a machine, known as the Lettuce Bot, is under development at Blue River Technologies, a company headed by a pair of Stanford University-trained engineers and backed by marquee Silicon Valley investors including Kholsa Ventures and startup guru Steve Blank, the Economist reports.

At the heart of the robot is a computer-vision algorithm that compares snapshots of lettuce rows taken by a camera on the tractor to a database of more than a million images.

The technology is able to distinguish individual heads of lettuce and weeds. When the machine identifies a weed or a head of lettuce growing too close to another one, it hits them with a dose of highly-concentrated fertilizer. In high concentrations, fertilizer can be as potent as pesticide, the Economist explains.

The dose kills off the weed or unwanted head of lettuce, then gets diluted enough in the ground to nourish nearby plants.

The robot is expected to debut on the market in 2013. Other technologies in the works at Blue River include a robot that kills weeds with a rotating blade instead of the fertilizer, which should appeal to organic farmers who eschew industrial fertilizers.


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Workshop NEV2013 "Nitrogen, Environment and Vegetables": registrations, call for abstracts and sponsorships open!

All Seasons Produce Apples

The European Commission - DG Environment and the University of Torino (Italy) organize the NEV2013 Workshop on ‘Nitrogen, Environment and Vegetables’ next 15-17 April 2013, in Torino. The workshop is organized in the framework of a tender coordinated by Alterra (NL) for providing support to the implementation of Nitrates Directive (91/676/EEC). It is addressed to policy makers, farmers organizations, researchers and extension professionals.

Over the last decades, the increasing demand for available and affordable products has been tackled by increasing agricultural inputs to obtain greater yields, often leading to an overuse or a misuse. Crop over-fertilization has raised the public awareness on the risks of water eutrophication. There is a striking need for making nitrogen fertilizer use for all crops more effective, in order to reduce its potential negative effects on the environment and, with regard to vegetable crops, on human health when supplied to plants as nitrate. In recent years, a number of research programs have assessed the effects of nitrogen fertilization methods, fertilizer rate and source on nitrogen uptake and plant growth of many vegetable species. On this basis,  tools to determine nitrogen losses owing to the different cultivation systems for vegetables and to the different climate and soil conditions have been developed. Their spread implementation can lead to environmental-friendly fertilization strategies, applied taking into consideration the needs and suggestions of researchers, farmers and consumers, and involving policy makers too.

The workshop focuses on the critical issues of the Nitrates Directive in vegetable crops in European Countries. The main topics will be nitrogen fertilization management, strategies to improve nitrogen and water use efficiency, relationship between nitrogen and other nutrients, crop residues management, crop rotation and monitoring of the environmental pollution caused by nitrogen losses from vegetable crop systems.

The workshop aims to enhance the information exchange among Member States on the implementation of Nitrates Directive in vegetable crops. The format of the workshop includes plenary sessions with invited speakers, oral and poster sessions, open field and protected cultivation farm visits, interacting discussions on crop practices, sub-topic specific workshop sessions. There is no fee for the participation to the workshop.

We are happy to invite you to attend the NEV2013!

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Campaigners demand supermarket
watchdog given teeth


Activists today staged a demonstration to highlight the need for the UK government to ensure the new supermarket watchdog being introduced has the power to fine supermarkets for unfair buying practices that hit the working conditions and environmental practices of suppliers and farmers overseas and in Britain.

Campaigners from leading UK development and environmental charities ActionAid, Friends of the Earth, SPEAK, Traidcraft and War on Want held the protest at the Department for Business, Innovation and Skills.

The charities warn that if legislation now going through parliament leaves the proposed supermarket watchdog, the Groceries Code Adjudicator, without the power to fine supermarkets from day one it will struggle to enforce the Groceries Code and stop supermarkets shifting their risks and unexpected costs onto their suppliers..

They say the government’s proposals to “name and shame” offending supermarkets will not deter them from continuing to engage in unfair trading, despite negative publicity, reinforcing the findings of the Competition Commission’s 2008 investigation into supermarket practices.

Murray Worthy, supermarkets campaigner at War on Want, said: “It is vital the government gives the supermarket watchdog the power to fine. A watchdog that is all bark and no bite won’t be able to stop supermarkets bullying their suppliers.”

Paul Spray, Traidcraft’s policy director, said: “If a supermarket ignores the Groceries Code it has signed up to, it needs more than a slap on the wrist. Giving the watchdog the power to fine sends a strong signal that it means business and developing country suppliers can have confidence that supermarkets will be held to account for their abusive practices”.

The big four supermarkets - Tesco, Asda, Sainsbury’s and Morrisons - control over 75 per cent of the grocery market in the UK, giving them enormous power to dictate terms and conditions to their suppliers.

The campaigners claim these pressures are often passed on, either through lower wages and poorer conditions for workers or reduced environmental standards.


Publication date: 10/24/2012

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