Understanding soil nitrogen management using synchrotron technology

How different fertilizers affect soil organic matter and what that means for crops

2013-10-01

(Press-News.org) As food security becomes an increasingly important global issue, scientists are looking for the best way to maintain the organic matter in soils using different methods of fertilization and crop rotation.

Increasing the organic matter in soils is key to growing crops for numerous reasons, including increased water-holding capacity and improved tilth. Scientists have recently used the Canadian Light Source (CLS) to evaluate the effects of various sources of supplemental nitrogen fertilizer on the chemical composition of soil organic matter. Results of their experiments to study this question were recently published in the journal Biogeochemistry.

"The big question I had when we started this research was how different nitrogen fertilizer supplements affected the overall soil organic matter composition," says Dr. Adam Gillespie, a post-doctoral fellow working with Agriculture and Agri-Food Canada (AAFC). "We also wanted to look at how we could optimize the use of nitrogen, since nitrogen fertilizers can be a solution, but also a problem."

Gillespie and his colleagues from AAFC, the University of Saskatchewan, St. Francis Xavier University, Lakehead University, and the CLS tested the hypothesis that the chemical composition of SOM would be different if the supplemental nitrogen originated from a synthetic fertilizer product, animal manure or a legume source.

The invention of synthetic fertilizer, where nitrogen is taken from an inert chemical form in the air and turned into ammonia, has had a profound effect on nitrogen cycling. In fact, astonishingly, humans have doubled the amount of available nitrogen in the biosphere.

According to Gillespie, 40 per cent of people alive today derive their nitrogen nutrition from synthetically-fixed fertilizer.

"Indeed, fertilization has had a profound effect on humanity as a whole. The downside of nitrogen fertilization is that run-off of nitrates to the surface waters or leaching of nitrates to groundwater cause problems with water quality and eutrophication in lakes. The recent algal blooms on Lake Winnipeg are a prime example of this nitrogen pollution. Secondly, nitrogen can be converted to nitrous oxide, which is an extremely potent greenhouse gas. Before fertilizers, nitrogen was introduced into the soil through rainfall or native pulse crops, so when fertilizer was developed, it revolutionized farming."

He cites three common ways for producers to introduce nitrogen into soil: synthetic fertilizer; manure or other organic amendments; and through cultivation of nitrogen fixing pulse crops. For all these methods, the nitrogen comes in different forms. Synthetic fertilizer is available as a variety of commercial products, with different nitrogen-release times, whereas manure and pulse crops need to be broken down by microbial decomposition before nitrogen becomes available.

Gillespie explained that fungi is great at breaking down lignin in plants and bacteria can help break down the rest, but adds, "nitrogen shifts the ability of bacteria to compete, so we are hoping to find out more about the role of fungi in the decomposition of organic matter in soil". Manure and pulse crops also add more organic matter to the soil, a benefit not realized using synthetic fertilizers.

The results of the experiment showed that organic matter in soil was heavily influenced by the type of supplemental nitrogen added.

"The overall trend showed that N additions allowed crop residues to decompose more completely. Specifically, we found less plant-type compounds in soils receiving nitrogen. In addition, we found that among the different nitrogen treatments, manure-enriched soil had the highest amounts of compounds related to microbial turnover," said Gillespie. The findings will prove important for farmers and scientists alike as they work to maximize the potential growth of food while maintaining healthy soils.

INFORMATION:

ELSE PRESS RELEASES FROM THIS DATE:

Tests in mice identify compound that may keep survivors of brain aneurysms from succumbing to stroke

2013-10-01

Johns Hopkins researchers, working with mice, say they have identified a chemical compound that reduces the risk of dangerous, potentially stroke-causing blood vessel spasms that often occur after the rupture of a bulging vessel in the brain. They say their findings offer clues about the biological mechanisms that cause vasospasm, or constriction of blood vessels that reduces oxygen flow to the brain, as well as potential means of treating the serious condition in humans. When an aneurysm — essentially a blister-like bulge in the wall of a blood vessel — bursts, blood ...

Scripps Florida scientists develop new process to create artificial cell membranes

2013-10-01

JUPITER, FL – October 1, 2013 – The membranes surrounding and inside cells are involved in every aspect of biological function. They separate the cell's various metabolic functions, compartmentalize the genetic material, and drive evolution by separating a cell's biochemical activities. They are also the largest and most complex structures that cells synthesize. Understanding the myriad biochemical roles of membranes requires the ability to prepare synthetic versions of these complex multi-layered structures, which has been a long-standing challenge. In a study published ...

What makes us left or right handed? New study rules out strong genetic factors

2013-10-01

Around 10 per cent of the UK is left handed — and that percentage remains consistent in many populations around the world. But why exactly someone is left or right handed remains unclear. New research from The University of Nottingham's Professor John Armour and Dr Angus Davison, in collaboration with UCL's Professor Chris McManus, has ruled out a 'strong genetic determinant' in influencing handedness. The researchers conducted a twin study examining the whole genome — which contains hereditary information — of nearly 4,000 subjects from the London Twin Research Unit ...

Bad luck? Knocking on wood can undo jinx: study

2013-10-01

Knocking on wood is the most common superstition in Western culture used to reverse bad fortune or undo a "jinx." Other cultures maintain similar practices, like spitting or throwing salt, after someone has tempted fate. Even people who aren't particularly superstitious often participate in these practices. A new study from the University of Chicago Booth School of Business finds that these superstitions actually do "reverse" perceived bad fortune. People believe that negative outcomes are especially likely after a jinx. If someone says, "No one I know will ever get ...

Regular primary care visits lower colorectal cancer incidence, death, and all-cause mortality

2013-10-01

1. Regular primary care visits lower colorectal cancer incidence, death, and all-cause mortality Medicare beneficiaries with more visits to their primary care physician (PCP) have lower colorectal cancer (CRC) incidence, CRC-specific mortality, and all-cause mortality. CRC is preventable with appropriate screening and polypectomy, yet many of the people who could benefit from it either are not screened, or do not start screening early enough. Recommendations from physicians are the strongest predictors of adherence to CRC screening guidelines. Researchers hypothesized ...

Medicare plans understate risky prescribing rates

2013-10-01

PROVIDENCE, R.I. [Brown University] — A new study reveals widespread inaccuracy in a quality measure that is self-reported by Medicare Advantage health plans. Researchers found that the vast majority in a sample of 172 such insurers significantly understated their rate of high-risk medication prescriptions. The average rate of prescribing at least one of about 100 medicines deemed risky for the elderly was 26.9 percent of patients over 65, according to the researchers' calculations, compared to the 21.1 percent of patients reported by the plans. The average plan, therefore, ...

New study shows blood test detected cancer metastasis

2013-10-01

San Jose, CA and Göttingen, Germany -- Researchers from the University Göttingen Institute of Veterinary Medicine and Chronix Biomedical have published a new study exploring the genetic hallmarks of canine mammary cancer. Appearing in the peer-reviewed journal PLOS ONE, the paper identifies important similarities and differences between human and canine breast tumors, providing a strong platform for future research using the canine model system. (Note to Editors: The paper is accessible here.) As part of the project, the research team successfully implemented Chronix ...

Leisure-time exercise could lower your risk of high blood pressure

2013-10-01

Physical activity in your leisure time could help keep your blood pressure at a healthy level, new research in the American Heart Association journal Hypertension suggests. Researchers pooled results from 13 studies on the effects of physical activity on blood pressure. The studies involved 136,846 people in the United States, Europe or East Asia who initially had healthy blood pressure. More than 15,600 later developed high blood pressure during follow-up periods ranging from two to 45 years. People who exercised more than four hours per week in their leisure time had ...

Finding the place where the brain creates illusory shapes and surfaces

2013-10-01

The logo of the 1984 Los Angeles Olympics includes red, white and blue stars, but the white star is not really there: It is an illusion. Similarly, the "S" in the USA Network logo is wholly illusory. Both of these logos take advantage of a common perceptual illusion where the brain, when viewing a fragmented background, frequently sees shapes and surfaces that don't really exist. "It's hallucinating without taking drugs," said Alexander Maier, assistant professor of psychology at Vanderbilt University, who headed a team of neuroscientists who has pinpointed the area ...

Secrets of Antarctic extremohiles that survive in cold salty water

2013-10-01

SYDNEY: A team led by scientists at the University of New South Wales has uncovered the genetic secrets of "extremophile" microbes that can survive in water temperatures as low as minus 20 degrees in the saltiest lake in Antarctica. Deep Lake, about five kilometres from Davis Station, was formed about 3500 years ago, when the Antarctic continent rose, isolating a section of ocean. The water in the 36-metre deep lake is now so salty it remains in liquid form down to a temperature of minus 20 degrees. "The lake has the distinction of being the least productive lake ever ...

Understanding soil nitrogen management using synchrotron technology

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: