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.

 

Important factors in preserving biodiversity on coffee plantations


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Black coffee beans begin as red cherry-like fruits on a tree. (Coffee Management Services/flickr)

Jenna Ladd | April 19, 2018

As final exams loom closer, many students may find themselves relying a little too heavily on coffee to get them by. But what is the relationship between the black midnight oil and biodiversity?

There are two distinct coffee plants that produce the stuff that fills students’ mugs: coffee arabica and coffee robusta. Arabica plants provide fuel for the coffee connoisseur as its flavor is know for being smoother, richer and more nuanced than coffee robusta. The two plants require different growing conditions, too. Arabica does well in areas that are partly shaded by surrounding canopy while robusta grows better in cleared out areas with more sun.

Researchers from the Wildlife Conservation Society, Princeton University and the University of Wisconsin-Madison sought to determine whether there was a difference in impacts on biodiversity between the two plants. They collected bird species biodiversity data from coffee plantations in Western Gnats, India between 2013 and 2015. Some of the plantations grew arabica coffee while others grew robusta. Those areas producing arabica had roughly 95 percent canopy tree cover, and those areas growing robusta had 80 percent canopy tree cover. Shockingly, however, this had little effect on bird biodiversity. The difference between the number of species each of the areas supported was not significant.

“An encouraging result of the study is that coffee production in the Western Ghats, a global biodiversity hotspot, can be a win-win for birds and farmer,” said lead author Charlotte Chang to SIERRA magazine.

The story is not the same on a global scale, however. It has become increasingly popular for coffee farmers in South America and other parts of Asia to clear-cut forests around coffee plantations to make harvesting easier and increase plant productivity.

Researchers suggest that coffee consumers take more time to consider in what conditions their cup of joe was grown. If coffee is labeled Rainforest Alliance Certified or Bird Friendly, it is likely have had less of a negative impact on land use and biodiversity.

Carbon dioxide makes food less nutritious


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Less nutritious crops could pose health problems for many people worldwide who rely heavily on rice as their main food source. (Rob Bertholf/flickr)

Jenna Ladd | April 5, 2018

The changing climate is forcing farmers to adapt, but how do rising greenhouse gas levels impact the food on our dinner plates?

A Harvard School of Public Health study looked at how more carbon dioxide in the atmosphere affects nutrient levels in six primary food crops: wheat, rice, field peas, soybeans, corn and sorghum. The researchers split plants of the same crop up between two groups. The first group was cultivated in an environment with between 363 and 386 parts per million carbon dioxide (CO2). This was the amount of CO2 in the atmosphere at the time of the study, in 2014. The second group of plants grew up in an environment with between 546 to 586 parts per million of the greenhouse gas in the air. This is roughly the concentration of CO2 expected to be in Earth’s atmosphere within fifty years.

When it was time, the scientists harvested the crops and measured levels of key nutrients in them. They looked specifically at zinc, protein and iron. The study found that plants grown in environments with higher concentrations of CO2 were less nutritious than their counterparts. Wheat, rice and soybeans were all found to have lower levels of zinc, protein and iron in the higher CO2 conditions.

Animal products are the primary source of protein for most people in the U.S., but people in other parts of the world rely heavily on rice and wheat as their main protein providers. These foods are naturally low in protein and further deficiency could be devastating. One study in the Journal Environmental Health Perspectives found that these projected impacts could cause an additional 150 million people worldwide to be protein deficient by 2050. Protein deficiency can cause low birth weight and other health problems that stunt growth and development.

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.

Hot, drier weather poses risks to beer production


 

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Hops, the grain that gives India Pale Ales their distinct, bitter flavor, has become more expensive as Northwestern weather grows hotter. (Josh Delp/flickr)
Jenna Ladd | March 16, 2018

Per tradition, many will head to a pub for a beer tomorrow to ring in St. Patrick’s Day. Few, however, are likely to think about the way our changing climate impacts beer production.

Beer is made with a fermented grain, namely barely and hops, and water. All these key ingredients become more difficult to source as weather becomes more extreme.

More than seventy percent of hops, which give some beers their bitter flavor, are produced in Washington state, specifically in the Yakima Basin. NOAA National Centers for Environment Information reports that in 2015, that area of Washington faced severe drought conditions from June through August. In fact, hop’s whole growing season in Washington that year was uncommonly warm. The state still managed to produce nearly 60 million pounds of hops, but yields for certain varieties of the grain were much lower than expected. The warmer weather in that region is expected to continue hurting hop production, specifically European varieties that are grown there.

Brewing beer also requires great quantities of water. Drought conditions in many parts of California have made beer production difficult and costly. For taste, brewers prefer to use river and lake water, but as river flows reduce and reservoirs run dry, many breweries have had to switch to groundwater. Groundwater is typically mineral-rich and can give beer a funny taste. Some brewers have likened it to “brewing with Alka-Seltzer.”

In 2015, top breweries released a statement detailing the way climate change affects production,

“Warmer temperatures and extreme weather events are harming the production of hops, a critical ingredient of beer that grows primarily in the Pacific Northwest. Rising demand and lower yields have driven the price of hops up by more than 250% over the past decade. Clean water resources, another key ingredient, are also becoming scarcer in the West as a result of climate-related droughts and reduced snow pack.”

New Belgium and Sierra Nevada are among many breweries that have implemented internal energy conservation practices. Sierra Nevada uses more than 10,000 solar panels to supply energy to its California brewery and New Belgium employees started giving up their bonuses to purchase wind turbines for the company over twenty years ago.  As grains, water and energy become more costly, brewers and consumers alike may benefit from considering the ecological impact each pint of beer has this Saturday.

 

Mid-American Monarch Conservation Strategy draft released


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Female monarchs lay their eggs in milkweed pods. (Charles Dawley/flickr)
Jenna Ladd | March 15, 2018

A draft of the Mid-America Monarch Conservation Strategy was released on Monday, and Iowa plays an integral role in its success.

North American monarch butterfly populations have decreased by 80 percent in the last two decades, and their numbers are less than half of what is needed to guarantee a sustainable population. The black and gold pollinators spend their winter months in Mexico and southern California and travel to the northern midwest for the summer. Female monarchs lay eggs exclusively in milkweed pods.

Released by the Midwest Association of Fish and Wildlife Agencies, the conservation strategy draft explains that midwestern states plan to establish 1.3 billion new milkweed stems over the next two decades. The Iowa Monarch Conservation Strategy is included within the midwestern effort. Written by Iowa State University’s Iowa Monarch Conservation Consortium, its aims to establish between 480,000 and 830,000 acres on monarch habitat by 2038.

Mike Naig, Iowa Secretary of Agriculture, said, “The consortium has worked collaboratively with diverse stakeholders to develop a comprehensive plan to expand habitat on our agricultural land, urban areas, roadsides, and other public land. We appreciate the many partners that have been involved and are encouraged by the work already underway.”

Iowa’s strategy provides evidence-based recommendations for creating monarch habitat and aims to document all voluntary efforts. 127 to 188 million new milkweed stems are estimated to be planted in Iowa in accordance with the plan.

Given that the vast majority of Iowa land is in agricultural production, the plan’s authors emphasize that agricultural lands must be a part of the solution. The strategy considers both expanding on existing conservation practices and planting milkweed stems in underutilized farm land as viable options. The U.S. Fish and Wildlife Services will decide in June 2019 whether the monarch butterfly should be protected under the Endangered Species Act.

Chuck Gipp, director of the Iowa Department of Natural Resources, said, “Iowa falls entirely within the monarch’s northern breeding core. This means that every patch of milkweed habitat added in Iowa counts, and Iowa is perfectly situated to lead the way in conservation efforts for the monarch butterfly. The recovery cannot succeed without Iowa.”

The full draft of the Mid-American Monarch Conservation Strategy is available here.
The complete Iowa Monarch Conservation Strategy is available here.

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.