INRA research scientists in Dijon have shown that the ability of soils to eliminate N2O can mainly be explained by the diversity and abundance of a new group of micro-organisms that are capable of transforming it into atmospheric nitrogen (N2).
Nitrous oxide (N2O) is a potent greenhouse gas that is also responsible for destroying the ozone layer. INRA research scientists in Dijon have shown that the ability of soils to eliminate N2O can mainly be explained by the diversity and abundance of a new group of micro-organisms that are capable of transforming it into atmospheric nitrogen (N2). These results, published in Nature Climate Change in September 2014, underline the importance of microbial diversity to the functioning of soils and the services they deliver.
Nitrous oxide (N2O) is one of the principal greenhouse gases, alongside carbon dioxide (CO2) and methane (CH4); it is also responsible for destruction of the ozone layer. Terrestrial ecosystems contribute to about 70% of N2O emissions, at least 45% being linked to the nitrogen-containing products found in agricultural soils (fertilisers, slurry, manure, crop residues, etc.). "In order to lower emissions of N2O and develop more environmentally-friendly agriculture, it is important to understand the processes involved not only in its production but in its elimination," explain the scientists. This elimination can be achieved by micro-organisms living in the soil that are able to reduce N2O into nitrogen (N2), the gas that makes up around four-fifths of the air we breathe and which has no impact on the environment.
Greenhouse Gases: New Group of Soil Micro-Organisms Can Contribute to Their Elimination
Ultimately, algae blooms are caused by excess phosphorus in the water that provides the algae with the fertilizer it needs to grow exponentially, given enough sun and warm enough water temperatures. But the source of that phosphorus can vary.
From the 1960s to the 1980s, said Glenn Benoy, a senior water quality specialist and science adviser with the International Joint Commission. the main source of phosphorus was sewage plants. The algae problem was considered so serious that communities on the shores of the lake poured billions of dollars into sewage infrastructure upgrades and implemented laws banning phosphorus in laundry detergents.
This time the main problems are thought to be ones that governments have much less direct control over. To some extent, they include the application of fertilizers to lawns and golf courses, growing expanses of pavement in urban areas that cause water to drain more quickly into waterways without being filtered by vegetation, and invasive zebra mussels that release extra nutrients into the water as they feed. But those aren't thought to be the biggest cause.
"We think farming is the major culprit behind the current levels of phosphorus that's in runoff and the phosphorus loads that are getting dumped into the western basin of Lake Erie," Benoy told CBC News.
The commission's report suggested that changes to farming practices were largely to blame for recent blooms.
"The main changes that are responsible have to do with intensification of farming – getting more out of the land than we did historically," Benoy said, adding that that includes things like:
- More livestock farming and greater application of their waste to fields.
- Higher application of fertilizers in general.
- An increase in corn farming in the U.S. Midwest, partly to meet a demand for ethanol fuel.
Corn is demanding when it comes to fertilizers," Benoy said. In fact, there's so much corn being farmed in some parts of the region that it's not possible to deliver the amount of fertilizer they require in the spring, said Ivan O'Halloran, an associate professor at the University of Guelph's campus in Ridgetown, Ont., who studies soil fertility and nutrient use.
As a result, companies sometimes offer discounts to farmers who buy and apply their fertilizer to the surface of their fields in the fall – a practice that appears to significantly increase the rate at which it gets washed into local waterways.
The algae problem in Lake Erie that fouled the water that hundreds of thousands of people rely on for drinking, cooking and bathing last week was thought to have been successfully eliminated in the 1980s. Farming is the main culprit today, and climate change has become an "aggravating factor."
Lake Erie's Algae Explosion Blamed on Farmers
It was a letter officials with the Cumberland County Library System were surprised to receive.
The system had spent some time working in partnership with the Cumberland County Commission for Women and getting information from the local Penn State Ag Extension office to create a pilot seed library at Mechanicsburg’s Joseph T. Simpson Public Library.
The effort was a new seed-gardening initiative that would allow for residents to “borrow” seeds and replace them with new ones harvested at the end of the season.
Through researching other efforts and how to start their own, Cumberland County Library System Executive Director Jonelle Darr said Thursday that no one ever came across information that indicated anything was wrong with the idea. Sixty residents had signed up for the seed library in Mechanicsburg, and officials thought it could grow into something more.
That was, until the library system received a letter from the state Department of Agriculture telling them they were in violation of the Seed Act of 2004.
Darr explained that the Seed Act primarily focuses on the selling of seeds — which the library was not doing — but there is also a concern about seeds that may be mislabeled (purposefully or accidentally), the growth of invasive plant species, cross-pollination and poisonous plants.
The department told the library it could not have the seed library unless its staff tested each seed packet for germination and other information. Darr said that was clearly not something staff could handle.
Though the seed library is no longer an option, Darr said the department has left it open to the library to host “seed swap” days where private individuals can meet and exchange seeds. As long as the library system itself is not accepting seeds as donations, Darr said such an event would meet the requirements of the act.
State Department of Agriculture Cracks Down on Seed Libraries
"Water scarcity poses the most severe human security challenge in Iran today," said Gary Lewis, United Nations Resident Coordinator for Iran.
The cause of the crisis is not in residential use; agriculture accounts for about 90 percent of water consumption, with much of it being used inefficiently.
Government figures show that only a third of agricultural water use is efficient, say U.N. officials. This inefficient management stretches across Iran and other countries in the region, including neighboring Iraq and Afghanistan where wars make it difficult to tackle environmental issues.
Major rivers in the cities of Isfahan and Shiraz, and on Iran's border with Afghanistan, have dried up. The depletion of the Tigris and Euphrates rivers in Iraq has contributed to other environmental problems such as dust and sand storms.
With government policies mired in bureaucracy, the U.N. has offered to help. In 2012, the world body launched a pilot program to work with farmers near Lake Orumieh.
Farmers learned how to make compost, switched to organic-based fertilisers and attended weekly classes on water management which led to a 35 percent drop in consumption.
The new techniques have also allowed farmers to reduce costs and increase variety of crops from just wheat and beets to add maize, squash, onions and tomatoes.
Farming Reforms Offer Hope for Iran's Water Crisis
