Not all of nitrogen for plants comes from atmosphere: Study

Davis (California): Contrary to popular belief that all of the nitrogen on Earth available to plants comes from the atmosphere, a study from the University of California, Davis, indicates that more than a quarter comes from Earth's bedrock.

Up to 26 percent of the nitrogen in natural ecosystems is sourced from rocks, with the remaining fraction from the atmosphere. This newly identified source of nitrogen could also feed the carbon cycle on land, allowing ecosystems to pull more emissions out of the atmosphere, the study published in the journal Science said.

"Our study shows that nitrogen weathering is a globally significant source of nutrition to soils and ecosystems worldwide," said co-lead author Ben Houlton, a professor in the UC Davis Department of Land, Air and Water Resources and director of the UC Davis Muir Institute. "This runs counter the centuries-long paradigm that has laid the foundation for the environmental sciences. We think that this nitrogen may allow forests and grasslands to sequester more fossil fuel CO2 emissions than previously thought."

Ecosystems need nitrogen and other nutrients to absorb carbon dioxide pollution, and there is a limited amount of it available from plants and soils. If a large amount of nitrogen comes from rocks, it helps explain how natural ecosystems like boreal forests are capable of taking up high levels of carbon dioxide.

The study also said that large areas of Africa are devoid of nitrogen-rich bedrock while northern latitudes have some of the highest levels of rock nitrogen weathering. Mountainous regions like the Himalayas and Andes are estimated to be significant sources of rock nitrogen weathering, similar to those regions' importance to global weathering rates and climate. Grasslands, tundra, deserts and woodlands also experience sizable rates of rock nitrogen weathering.

Following the discovery the researchers now want the textbooks taught in schools to be changed accordingly. "While there were hints that plants could use rock-derived nitrogen, this discovery shatter the paradigm that the ultimate source of available nitrogen is the atmosphere”, said Kendra McLauchlan, program director in the National Science Foundation's Division of Environmental Biology, which co-sponsored the research.

“Nitrogen is both the most important limiting nutrient on Earth and a dangerous pollutant, so it is important to understand the natural controls on its supply and demand. Humanity currently depends on atmospheric nitrogen to produce enough fertilizer to maintain world food supply. A discovery of this magnitude will open up a new era of research on this essential nutrient”, Kendra McLauchlan added. Source: ummid.com

Read More........→July 08, 2020

Warnings on individual cigarettes could reduce smoking

• Health warnings printed on individual cigarettes could play a key role in reducing smoking, according to new research from the University of Stirling.
• Experts from Stirling's Institute of Social Marketing examined smokers' perceptions of the warning 'Smoking kills' on individual cigarettes, as opposed to the message only appearing on packs.
• The team, led by Dr Crawford Moodie, found that smokers felt the innovative approach has the potential to discourage smoking among young people, those starting to smoke, and non-smokers.
• Participants felt that a warning on each cigarette would prolong the health message, as it would be visible when taken from a pack, lit, left in an ashtray, and with each draw, thus making avoidant behaviour more difficult.
• The visibility of the warning to others was perceived as off-putting for some because it was associated with a negative image. Within several female groups, the warnings were viewed as depressing, worrying and frightening; with it suggested that people would not feel good smoking cigarettes displaying a warning.
• The possibility of warnings on cigarettes is included in the Scottish Government's tobacco-control action plan, 'Raising Scotland's Tobacco-free Generation'. It suggests changes to "colour, composition and / or warning messages on each stick".
• The Canadian Government has also held a consultation on the proposals and published their findings earlier this month [August 2019].
• The Stirling study canvassed the opinion of 120 smokers, aged 16 and over, in 20 focus groups held in Edinburgh and Glasgow in 2015. Within every group, participants felt that warnings on individual cigarettes would potentially have an impact on themselves or others.
• "The consensus was that individual cigarettes emblazoned with warnings would be off-putting for young people, those starting to smoke, and non-smokers," Dr Moodie says. "This study suggests that the introduction of such warnings could impact the decision-making of these groups. It shows that this approach is a viable policy option and one which would - for the first time - extend health messaging to the consumption experience."
• The research - funded by Cancer Research UK - also involved: Dr Rachel O'Donnell, Joy Fleming, Dr Richard Purves and Jennifer McKell (all of the ISM at Stirling), and Fiona Dobbie, of the Usher Institute of Population Health at the University of Edinburgh.
• Professor Linda Bauld, Cancer Research UK's prevention expert, said: "Too many young people are still taking up smoking. Government anti-smoking campaigns and tax rises on cigarettes remain the most effective methods to stop young people starting smoking, but we need to continue to explore innovative ways to deter them from using cigarettes to ensure that youth smoking rates continue to drop. "This study shows that tactics like making the cigarettes themselves unappealing could be an effective way of doing this."Source: https://www.domain-b.com/

Read More........→July 07, 2020