Skip to main content

Satellite study finds ammonia hotspots over agricultural areas (downtoearth,)

A satellite study of airborne ammonia gas has revealed four major hotspots over productive agricultural regions across the world. Increased atmospheric ammonia is linked to poor air and water quality.

Using data from NASA’s Atmospheric Infrared Sounder satellite instrument, researchers led by the University of Maryland (UMD), discovered increased ammonia concentrations from 2002 to 2016 over agricultural centres in the US, Europe, China and India. The study was published last month in the journal, Geophysical Research Letters.

Harmful effects

Increased ammonia is linked to fertilizers, livestock animal wastes, changes in atmospheric chemistry and warming soils that retain less ammonia.

Gaseous ammonia is a natural part of the Earth’s nitrogen cycle, but excessive ammonia is harmful to plants, the study adds. Ammonia gas can also fall back to Earth and waterbodies, where it contributes to harmful algal blooms and “dead zones” with dangerously low oxygen levels.

“To control ammonia-related pollution, it is necessary to regulate fertilizer waste and agricultural residue burning. Increase in fertilizer use is the leading cause behind the increase of gaseous ammonia in the atmosphere. Except for a few countries in Europe, ammonia emission is not regulated. There is a growing awareness on how ammonia in the atmosphere affects the ecosystem and air and water quality, Juying Warner, associate research scientist in atmospheric and oceanic science at UMD, told Down To Earth.

According to researchers, the study results could help formulate strategies to control ammonia pollution near major agricultural areas.

Bad news for India

According to Warner, the ammonia concentration in the atmosphere over India is the highest in the world due to cattle population and excessive fertilizer use. “This will contribute to increased air quality problems,” she warned.

The use of nitrogen fertilizers has grown worldwide, contributing to the growing demand for food. Where fertilizers are subsided, the regulation of the fertilizer use is the biggest challenge.

“Subsidies lead to low price of fertilizers, farmers also tend to over-apply because they don’t want to take the risk of low yields,” Aimable Uwizeye, Food and Agriculture Organization expert, says.

According to Uwizeye, the best ways to reduce ammonia emissions are improvement in manure management system, reduction of excessive nitrogen in animal diets and recycling of manure in crop systems. Storage of manure with minimum risk of run-off and seepage as well as prevention of leaching to water bodies and riparian buffer zones is necessary to reduce ammonia emissions.

In India, we can try to improve the digestibility of protein compound in animal feed to reduce ammonia emissions. Uwizeye adds one should prioritise nitrogen use efficiency in livestock systems, identify hotspots and explore country-specific approaches to reduce ammonia pollution.

Popular posts from this blog

NGT terminates chairmen of pollution control boards in 10 states (downtoearth,)

Cracking the whip on 10 State Pollution Control Boards (SPCBs) for ad-hoc appointments, the National Green Tribunal has ordered the termination of Chairpersons of these regulatory authorities. The concerned states are Himachal Pradesh, Sikkim, Tamil Nadu, Uttarakhand, Kerala, Rajasthan, Telangana, Haryana, Maharashtra and Manipur. The order was given last week by the principal bench of the NGT, chaired by Justice Swatanter Kumar. The recent order of June 8, 2017, comes as a follow-up to an NGT judgment given in August 2016. In that judgment, the NGT had issued directions on appointments of Chairmen and Member Secretaries of the SPCBs, emphasising on crucial roles they have in pollution control and abatement. It then specified required qualifications as well as tenure of the authorities. States were required to act on the orders within three months and frame Rules for appointment [See Box: Highlights of the NGT judgment of 2016 on criteria for SPCB chairperson appointment]. Having

High dose of Vitamin C and B3 can kill colon cancer cells: study (downtoearth)

In a first, a team of researchers has found that high doses of Vitamin C and niacin or Vitamin B3 can kill cancer stem cells. A study published in Cell Biology International showed the opposing effects of low and high dose of vitamin C and vitamin B3 on colon cancer stem cells. Led by Bipasha Bose and Sudheer Shenoy, the team found that while low doses (5-25 micromolar) of Vitamin C and B3 proliferate colon cancer stem cells, high doses (100 to 1,000 micromolar) killed cancer stem cells. Such high doses of vitamins can only be achieved through intravenous injections in colon cancer patients. The third leading cause of cancer deaths worldwide, colon cancer can be prevented by an intake of dietary fibre and lifestyle changes. While the next step of the researchers is to delineate the mechanisms involved in such opposing effects, they also hope to establish a therapeutic dose of Vitamin C and B3 for colon cancer stem cell therapy. “If the therapeutic dose gets validated under in vivo

SC asks Centre to strike a balance on Rohingya issue (.hindu)

Supreme Court orally indicates that the government should not deport Rohingya “now” as the Centre prevails over it to not record any such views in its formal order, citing “international ramifications”. The Supreme Court on Friday came close to ordering the government not to deport the Rohingya. It finally settled on merely observing that a balance should be struck between humanitarian concern for the community and the country's national security and economic interests. The court was hearing a bunch of petitions, one filed by persons within the Rohingya community, against a proposed move to deport over 40,000 Rohingya refugees. A three-judge Bench, led by Chief Justice of India Dipak Misra, began by orally indicating that the government should not deport Rohingya “now”, but the government prevailed on the court to not pass any formal order, citing “international ramifications”. With this, the status quo continues even though the court gave the community liberty to approach i