On The Radio- Nitrogen oxide and agriculture


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Fields (Ivan Albrecht/flickr)

Kasey Dresser | April 23, 2018

This weeks segment looks at how agriculture affects nitrogen oxide emissions in California. 

Transcript: 

Agriculture is a large emitter of nitrogen oxide gases in California.

This is the Iowa Environmental Focus.

Over the last few years California has been working to reduce the amount of nitrogen oxide gases released in the air. Policy makers began by focusing on reducing the use of cars, trucks, and buses which are currently believed to be the largest source of nitrogen oxide emissions. New research has also shown that fertilizers with nitrogen can be a large factor. 

Excess amounts of nitrogen oxide can produce toxic smog and acid rain. Ecologist Maya Almaraz and her team at University of California, Davis used a plane attached with a chemiluminescence analyzer to detect the nitrogen oxide in the air. They flew over the entire state of California collecting data. The area with the most nitrogen oxide pollution was the Central Valley’s agricultural region.

According to this test and several others, croplands contribute anywhere from 20- 51 percent of the nitrogen oxide levels in the air. Almaraz warns that increasing temperatures will only increase nitrogen oxide emissions unless there are steps to reduce nitrogen fertilizer use. 

For more information, visit iowa-environmental-focus-dot-org.

From the UI Center for Global and Regional Environmental Research, I’m Betsy Stone.

 

Climate change affects crop yields in varying ways


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Soybeans are less sensitive to temperature and precipitation changes than corn plants. (Kevin Dooley/flickr)
Jenna Ladd | March 23, 2018

Researchers at the University of Nebraska recently published a study which details how climate change impacts crop yield variance on a hyper-local level.

The study analyzed U.S. Department of Agriculture data from more than 800 counties across North Dakota, South Dakota, Wyoming, Nebraska, Iowa, Colorado, Kansas, Oklahoma and Texas from 1968 through 2013. Collectively, they found that climate change caused about 25 percent of crop yield variance during that time. While temperature and precipitation changes were responsibile for 52 percent of crop fluctuations in some counties, they did not have any effect in others.

Similarly, the three crops that were studied: corn, soy and sorghum, all responded to the changing climate differently. Corn is more likely than the other two to be impacted by rising temperatures. When corn plants are not irrigated, yields are twice as likely to be harmed by increased temperatures. However, irrigated corn seemed to do relatively well in these conditions. Irrigated soy and sorghum plants were much less likely than non-irrigated plants to be negatively impacted by precipitation and temperature shifts too.

Suat Irmak and Meetpal Kukal are the study’s authors. They say that their work makes the case for continued climate change studies which consider different climate variables, crop types and growing conditions.

“I hope we are successful in getting across the message that there are changes in temperature and precipitation, (but) those changes are different over time and location, and they are having different impacts on our agricultural productivity,” Dr. Irmak said to the University of Nebraska. “That can help high-level advisers, decision-makers and policymakers to identify locations where those impacts are greatest so that resource allocation or re-allocation can make (fields) even more productive.”

The full study can be found in the journal Scientific Reports.

On The Radio- 793 gigagrams of mercury found in Alaska


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Glacier Bay National Park (pontla/flickr)

Kasey Dresser | March 5, 2018

This week’s segment looks at research published in last month’s Geophysical Research Letters about the amount of mercury found in Arctic permafrost in Alaska.

Transcript: 

New research states that Arctic permafrost in Alaska holds more mercury than expected.

This is the Iowa Environmental Focus.

Arctic permafrost is frozen soil, rock, and sediment that stays at or below freezing for at least two consecutive years. A quarter of the Northern Hemisphere’s landmass is covered by permafrost.

Recently a group of scientists drilled into 13 soil cores taken from different parts of Alaska. The findings reported that the permafrost held 793 gigagrams of mercury. This is equivalent to more than 15 million gallons or 23 Olympic size swimming pools. These numbers continue to increase if you add the current thawed layer of soil that sits above it.

By 2100 anywhere from 30 to 99 percent of the permafrost could have thawed leaving the question: Where will the mercury go?

Carl Lamborg, an assistant professor of ocean sciences at the University of California, Santa Cruz discussed in an interview that it’s unclear what will happen to the mercury when the permafrost thaws but there is reason for concern. More research will be needed to understand the impact of mercury in the atmosphere.

These new findings were published last month in the Geophysical Research Letters.

For more information, visit iowa-environmental-focus-dot-org.

From the UI Center for Global and Regional Environmental Research, I’m Betsy Stone.

Crop production linked to regional changes in climate


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Corn and soy plants can cool the climate on a regional level, but intensified conventional agriculture can harm water and soil quality. (Lana/flickr)

Jenna Ladd | February 14, 2018

A new study by researchers at Massachusetts Institute of Technology and Dartmouth College detail the way intensive agriculture has influenced precipitation and temperature patterns in the midwest.

During the second half of the 20th century, corn production in the midwest increased by 400 percent and soybean yields doubled due to more intensive agricultural practices. The study, which was published in Geophysical Research Letters, found that the midwest also saw significantly more precipitation and lower temperatures during the summer months over the same period of time. They concluded that the changes were not merely correlated, but that the land use change actually caused the regional climate changes.

The authors explain that each time plants take in carbon dioxide, they release moisture into the atmosphere through pore-like structures called stoma. With more plentiful and robust plants due to intensive agriculture, the amount of moisture corn and soy crops collectively release into the atmosphere has increased in the midwest since the 1950’s. This extra moisture, the study found, has caused summer air to cool and more precipitation to fall. In the last fifty years, average summertime rainfall in the midwest has increased by 15 percent and average summer temperatures have dropped by 0.5 degrees Celsius.

Roger Pielke Sr., a senior researcher at the University of Colorado at Boulder commented on the study, he said, “This is a really important, excellent study. The leadership of the climate science community has not yet accepted that human land management is at least as important on regional and local climate as the addition of carbon dioxide and other greenhouse gases into the atmosphere by human activities.”

Since completing the study, the researchers have developed a formula that accounts for the causative relationship between plants and regional climate changes that can be entered into U.S. regional climate models. It correctly predicted those changes that have been observed in the midwest over the last 50 years.

The study opens the door for further research into land use changes and how they can affect local climate.

On The Radio- The affects of mass producing corn


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Corn Fields (Victor Bayon/ flickr)

Kasey Dresser | January 29, 2018

This week’s segment looks at research from the University of Wisconsin regarding corn’s ability to adapt to environmental changes.

Transcript:

Researchers at the University of Wisconsin report that mass produced corn has lost its ability to adapt.

This is the Iowa Environmental Focus.

Like most plants, corn adapts to changes in the surrounding environment, including things like drought, wind, sunlight, and insects.

In order to mass produce corn, seed companies have breed the most productive corn varieties to fit local environmental conditions. However over the past 100 years, acclimating corn to a specific environment has impacted its ability to adjust to new or stressful environmental changes. The existing corn is strong and stable but not flexible.

To test this, the researchers planted 850 unique corn varieties in 20 different states and Canada. They tested 12,000 different plots and recorded  weather patterns and corn height. The corn with the most genetic selection performed the worst, producing the least amount of grain. According to University of Wisconsin Professor of Agronomy, Natalia De Leon, mass productivity is the tradeoff for flexibility. She worries the more corn is engineered to grow in a specific area, the less likely it will adapt well in other environments.

For more information, visit iowa-environmental-focus-dot-org.

From the UI Center for Global and Regional Environmental Research, I’m Betsy Stone.

 

California Wildfires


Kasey Dresser | January 5, 2018

Hello everybody!

I’m Kasey and I’m a student at the University of Iowa. I’m currently visiting home during winter break in beautiful San Diego, California. And as I’m sure you seen on the news I came home after an extremely destructive fire season.  Luckily I live closer to the coast so my home was not affected but my grandma and several of my friends were evacuated.  All of the local high schools, including my sisters, were closed. Last weekend, My dad and I headed inland to film the damage.

 

On The Radio – California lists glyphosate as a carcinogen


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Glyphosate is an active ingredient in Monsanto’s Roundup. (Mike Mozart/flickr)
Jenna Ladd | December 18, 2017

This week’s On The Radio segment discusses how some farm groups are suing California for considering glyphosate a cancer causing chemical. 

Transcript: Iowa and a dozen other state farm groups are suing California for listing glyphosate as a cancer causing chemical.

This is the Iowa Environmental Focus.

California’s Proposition 65 law from 1986 requires the state to protect drinking water from chemicals that can cause cancer or reproductive harm. And businesses must warn their users about potential chemical danger.

Glyphosate is a herbicide used in 250 crops and a key ingredient in Monsanto’s top selling weed killer, RoundUp. Back in 2016 Monsanto sued California to block the glyphosate listing but in July of this year, California made the decision to list glyphosate as a carcinogen.

This decision will cost Iowa farmers around 5 billion dollars. Crops with glyphosate will have to be separated, meaning extra time and labor costs not to mention a drastic drop in sales. Products with even trace amounts of glyphosate will be required to be labeled by 2018 in the state of California.

Glyphosate is believed to be one of the safer herbicides. It was approved by U.S. Environmental Protection Agency in the 1970s and is frequently re-tested. However, the International Agency for Research on Cancer determined glyphosate as a potential cancer causing substance in 2015.

The debate about glyphosate and its effects on human health will likely continue following California’s actions.

For more information, visit iowa-environmental-focus-dot-org.

From the UI Center for Global and Regional Environmental Research, I’m Betsy Stone.