City dwellers rejoice: spring greening comes earlier for urban plants


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The first signs of spring occur earlier in cities than surrounding rural areas, new research found (via Creative Commons).

Julia Poska | February 27, 2020

Vegetation starts turning green earlier in cities than surrounding rural areas, but urban plants are less sensitive to unseasonable warmth, new Iowa State University-led research found. The authors attribute the difference to the urban “heat island” effect.

Cities typically have somewhat higher temperatures than surrounding rural areas because materials like asphalt and brick absorb heat more readily than natural landscapes. For example, New York City is about 7 degrees Fahrenheit warmer than surrounding areas in summer, according to NASA’s Climate Kids site.

Researchers found this “heat island” phenomenon causes urban vegetation to perceive the start of spring and begin greening an average of six days earlier than surrounding rural plants.

As climate change progresses, however, plants in both rural and urban areas are responding to unseasonably warm temperatures by beginning growth earlier and earlier over time. Pollinators and last frosts have failed to keep up, which has damaged the early bloomers’ ability to survive and reproduce.

The study found that rural vegetation is more sensitive to early spring weather than urban vegetation, perhaps due to the urban heat island effect as well.

ISU Ph.D. student Ling Meng led the research team, which included CGRER member Yuyu Zhou, an ISU geological and atmospheric scientist, among others. The study, published this month in Proceedings of the National Academy of Sciences, was based on satellite images from 85 large U.S. cities from 2001 to 2014.

Zhou told the Iowa State News Service that this sort of research can help predict how plants will respond to climate change and urbanization.

ISU research complicates cover crops


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Cover crops hold onto soil and carbon during the off-season (via Creative Commons).

Julia Poska| November 13, 2019

Though cover cropping has proven advantageous for soil and water conservation in Iowa, the practice’s benefits to atmospheric quality may be negligible, new research from Iowa State University found.

When farm fields are left bare during the winter and spring, wind and water transport soil and nutrients off the land and into streams and rivers, degrading both the field and water quality. Exposed soil typically releases carbon into the atmosphere at increased rates compared to planted areas, contributing significantly to climate change.

Cover cropping involves planting alternative crops like rye or clover to cover and nourish the land throughout the off-season. The conservation practice holds soil in place, pulls atmospheric carbon into plant material and adds carbon back into soil upon decomposition. Sequestering carbon in plants and soil is key to combatting climate change.

That carbon may not remain in the soil for long, however. The new study, published in Global Change Biology Bioenergy,  found that the added soil carbon stimulates microbes in the soil that emit carbon dioxide back into the atmosphere as they digest the organic matter.

The research — conducted by ISU assistant professor of ecology, evolution and organismal biology Steven Hall and grad student Chenglong Ye —  highlights the need for a variety of solutions for the planet’s numerous natural resource problems. While cover crops are a proven protectors against water pollution, we will need to implement other strategies to make farming carbon neutral, too.

Iowa farmers implement sustainable practices


Photo by Alejandro Barru00f3n on Pexels.com

Tyler Chalfant | October 17th, 2019

Iowa farmers are implementing practices to increase sustainability and reduce environmental threats to public health, including crop rotation, use of cover crops, eliminating pesticides, and using alternatives to chemical weeding. One group called Practical Farmers of Iowa organized a series of educational field days over the summer, providing opportunities across the state for farmers to share and discuss these practices. One of the environmental threats in the state comes from nutrient runoff from agricultural fertilizers, which recently have contributed to the growth of toxic microcystins in some Iowa bodies of water, making sustainable farming not just an environmental issue, but a public health concern as well. 

Research published last month from Iowa State University scientists found that the widely-used practice of crop rotation helps to reduce pollution, but also depletes organic matter in soil over time. Rotating between corn and soybeans requires less nitrogen fertilizer than continuous corn production, as soybeans leave behind a nitrogen-rich residue in the soil. This allows farmers to save on costs and reduce nitrogen runoff into freshwater lakes and streams. However the abundance of nitrogen contributes to the growth of microbes which, on years when corn is planted, consume nutrients needed for corn production, depleting this organic material in the long run.

Iowa State research proposes ‘sustainable intensification’ of Iowa drainage network


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Drainage tile helps keep farm fields dry, but Iowa’s system needs a more sustainable upgrade (via Creative Commons).

Julia Poska | October 9, 2019

Agronomy researchers at Iowa State University have proposed ideas for an ambitious and much-needed update to Iowa’s agricultural drainage system. Their study makes suggestions for mitigating the effects of altered precipitation patterns due to climate change while reducing pollution to air and water.

The concept of “sustainable intensification” (the authors define this as “producing more food from the same amount of land with fewer environmental costs”) is at the core of the research. ISU agronomist Michael Castellano led the study in partnership with University of Kentucky and the Swiss Federal Institute of Technology ETH-Zurich.

Artificial drainage systems are comprised of underground pipes, tiles and drains that move water off farmland, discharging it into ditches that flow into natural surface waterbodies. Without this network, most of Iowa’s land would be too waterlogged to farm, but drainage systems increase runoff of nutrient and bacterial pollution from fields into waterways.

The increasing frequency of both intense rain events and draught in Iowa due to climate change is also putting extra pressure on those systems, which were designed before Iowa agriculture became so intense.  The study, published in Nature Sustainability, describes several solutions. “Controlled drainage,” or installing gates that can temporarily open/close at the ends of drains, could allow farmers to increase drainage during wet springs and retain more water during dry summers.

Installing narrower, shallower drains could further reduce nutrient concentration in drainage water, the authors claim. They say it could also reduce needed fertilizer inputs and decrease greenhouse gas emissions from the soil.

The study also describes the need to increase on-farm conservation practices, like returning some farmed land to wetland, in conjunction with updating infrastructure.

 

Researchers speak at statehouse about rising temperatures


Photo from Radio Iowa | Bill Gutowski speaks while Peter Levi listens in

Tyler Chalfant | September 24th

Professors from Iowa universities spoke at the statehouse last Wednesday, Radio Iowa reported. The 216 climate educators who issued the ninth annual Iowa Climate Statement represent 38 colleges and universities in the state. 

This year’s statement warned of the increased intensity and frequency of heat waves that Iowa will experience in the coming decades. The group projects that the number of days exceeding 90 degrees will more than double within the next two decades, and nearly triple by mid-century.

The scientists spoke about how these increased temperatures will put Iowans at greater risk of heat related illnesses, including heat exhaustion, heat cramps, heat stroke, or death. Scientists have predicted that rural areas will likely be hit the hardest by rising temperatures, and that the Midwest will see the greatest number of premature deaths caused by heat. 

Peter Levi, an Environmental Science professor at Drake University, said that those facing the most danger “include our friends and neighbors who work outside on a regular basis, older adults above age 65, infants and children, those individuals with chronic conditions, low-income households and our athletes.” 

Levi also said that extreme heat will harm the state’s livestock industry, as confined livestock are at increased risk of death, and won’t reach a marketable weight as quickly when stressed by high temperatures. 


“It’s not hopeless,” added Bill Gutowski, an Atmospheric Sciences professor at Iowa State University, indicating that there is still time to reduce greenhouse gas emissions. “I want people to realize it’s not hopeless and there are adaptations that we can do as well.”

Monarch Butterflies Migrating to Iowa


Monarch Butterflies Migrate to Iowa Every Year (Flickr).

Sthefany Nóbriga| May 8, 2019

 Researchers from Iowa State University predict that this spring Iowans will see the largest population of monarch butterflies in over a decade. 

The monarch butterflies migrate every winter to Canopy Forest in central Mexico. During the winter of 2013 to 2014, the monarch population plummeted, covering less than 2.5 acres of the forest, the lowest point of the population in the past two decades. This is partly because of the loss of summer breeding habitat and pesticide use. 

However, this past winter scientist noted Mexico’s most significant overwintering monarch population since 2007. Almost 200 million adult monarch butterflies were recorded, and now they are migrating up north.

According to the researchers from Iowa State University, the reason for the increase in the monarch population is due to mild winters in Mexico, and southern parts of the United States in comparison to other years. 

Scientists are hopeful and want to maintain the monarch population and preserve their numbers. But it is reported that there is a shortage of potential breeding habitats in Iowa to maintain a steady population. 

In order to maintain this population, there must be approximately 480,000 to 830,000 acres of habitat over the next 10 to 20 years according to Iowa Public Radio. 

If the weather stays favorable, Iowans will be seeing a large monarch population starting at the end of May or even early June. 

Tom Vilsack to deliver lecture next month


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Tom Vilsack currently leads the U.S. Dairy Export Council. (Iowa State University)

Jenna Ladd | October 25, 2017

Tom Vilsack will deliver a lecture at Iowa State University as a part of the National Affairs Series: “When American Values Are in Conflict” next month.

Vilsack served as Governor of Iowa from 1999 through 2007. His lecture, titled “Agriculture and Climate Change,” however, will center more around his work as Secretary of the U.S. Department of Agriculture (USDA) during the Obama administration. As USDA Secretary, Vilsack helped to develop and manage programs related to rural electrification, community mental health and refinancing farm homes, to name a few. He also managed the federal school lunch program and the Supplemental Nutrition Assistance Program (SNAP).

Vilsack currently serves as president and CEO of the U.S. Dairy Export Council, “a non-profit, independent membership organization that represents the global trade interests of U.S. dairy producers, proprietary processors and cooperatives, ingredient suppliers and export traders.”

Additional details about the lecture can be found here.

What: “Agriculture and Climate Change” lecture by Tom Vilsack

Where: Iowa State University Memorial Union-Great Hall

When: Thursday, November 16 at 7:00 pm

Cost: free, open to public

ISU Horticulture Research Station celebrates anniversary


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ISU’s Horticulture Research Station provides opportunities for hands-on research for students and faculty. (Iowa State University)

Jenna Ladd| September 22, 2017

Iowa State University’s Horticulture Research Station celebrated its 50th anniversary this week.

The anniversary was marked with a farmer’s market, farm tours, children’s games and a produce washing demonstration on Saturday.

The 235 acre station is home to 80 to 90 research projects each year. Scientists from horticulture, forestry, botany, ecology, plant pathology, entomology and natural resources use the space to study everything from vegetables to honeybees to wasps to swallows. The land bears apples, pumpkins, watermelon, hops, grapes and more.

Ben Pease is a Horticulture Research Associate at Iowa State. He said, “We are able to sell most of what we grow. If it’s part of a research project once it’s done we can sell it or we’re growing stuff to use the land we’re able to sell it,” to Iowa State Daily. Pease added that the station has made over a million dollars selling produce since 2006. Much of the food is sold to ISU’s dining halls, which buys about 5 tons of green peppers each year.

The land, which features a 15 acre lake as well, is located just three miles north of Ames on highway 69.

2016 Iowa Farm and Rural Life poll released


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Jenna Ladd | May 4, 2017

Results from the Iowa Farm and Rural Life poll were released last month, providing insight into rural public opinion on a variety of topics.

The Iowa Farm and Rural Life poll, managed by the Iowa State University Extension Sociology, was established in 1982 and is the longest running survey of its kind. This year’s survey was completed by 1,039 farmers, who were 65-years-old on average. The poll is sent to the same 2,000 farmers every year so that researchers can track changes over time. This year, it asked respondents about conservation techniques, farming practices, monarch butterfly population restoration and trustworthy information sources.

According to the poll, 42 percent of farmers surveyed practice no-till farming, which can be effective in reducing topsoil erosion. On average, farmers lose 5.8 tons of topsoil per acre per year which can lead to a loss of 15 bushels of yield per acre each year, according to the Corn and Soybean Digest. Buffer strips along water ways and field edges to filter nutrients and sediment from runoff was the most common conservation practice among respondents. Forty-six percent of farmers reported using buffer strips in 2015, while fewer than 40 percent reported implementing extended crop rotations, terraces, or ponds.

The survey also asked about participation in The Natural Resources Conservation Service (NRCS) programs. NRCS is the arm of the U.S. Department of Agriculture charged with the protection of natural resources on agricultural lands. It provides technical and financial support to farmers looking to conserve soil and water. More than 60 percent of farmers said that they were currently participating in an NRCS program, just about 34 percent said that they were not. For those not enrolled in NRCS programs, their primary reason was that they did not believe they had enough natural resources on their land to warrant participation.

The farm poll also analyzed which sources of agricultural advice respondents were most likely to trust. More than any other source, farmers said they would be most likely to trust another farmer that grows nearby.

The survey is collaborative project of Iowa State University Agriculture and Home Economics Experiment Station, ISU Extension Service and the Iowa Department of Agriculture and Land Stewardship. “Information from the Farm Poll is used to guide policy decisions and actions and as the basis for public policy seminars, Extension reports, radio and television broadcasts, and newspaper and journal articles,” reads the Iowa State University Extension site.

Iowa State researchers receive grants to improve glacier flow models and sea level predictions


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                         Calving of the Aialik Glacier in Kenai Fjords National Park in Alaska. (Alaska National Park Service)

Jake Slobe | February 15, 2017

Iowa State University’s Neal Iverson and a team of researchers are working on research that will predict how much glaciers will contribute to the rise of sea levels.

The research will focus on the extent to which glacier-flow to oceans is likely speed up over the next century as the climate warms.

Iverson, an Iowa State University professor of geological and atmospheric sciences who has studied glaciers in Iceland and Norway, and the rest of the research team will look to lab experiments and field work to build more realistic computer models of glacier flow.

Iverson said about the project:

“Glaciologists are trying to predict how fast glaciers will flow to the oceans. To do that, we need new lab and field data to include complexity in models that is usually neglected. These are complicated systems. Modeling them is hard. But we need to include how water in ice affects its flow resistance, and we need sliding laws that are based on the real topography of glacier beds and that include rock friction. Adding these things really matters.”

Two new grants will help Iverson and his team fund their research, both of which grants are from the National Science Foundation.  The research will also receive funding from the United Kingdom’s Natural Environment Research Council to support the work of applied mathematicians at the University of Oxford in England.

Iverson is the lead investigator on both grant proposals. The other researchers are Lucas Zoet, an assistant professor at the University of Wisconsin-Madison and a former postdoctoral research associate at Iowa State; Ian Hewitt, an associate professor and university lecturer at Oxford’s Mathematical Institute; and Richard Katz, a professor of geodynamics at Oxford.

The first project will look at temperate ice, or ice at its melting point, and how this soft, watery ice resists deformation. That’s important because the resistance to deformation of temperate ice at the edges of ice streams – areas of rapid ice flow within the Antarctic ice sheet that can be hundreds of miles long and tens of miles wide – holds back the flowing ice.

The second project will support development of better “sliding laws” to help predict the sliding speeds of glaciers and ice sheets. Sliding laws are the mathematical relationships between the glacier sliding speed and the factors that control it, such as the stresses below the glacier, the water pressure there, the topography of the glacier bed and the concentration of debris in glacier ice.

Both projects will use the glacier sliding simulator Iverson has been using since 2009 to study glacier movement.

The new projects will add complexity to Iverson’s lab experiments. Debris, for example, will be added to the ice ring to study friction between it and the rock bed during sliding. In other experiments, temperate ice will be sheared between rotating plates to study how its resistance to flow depends on its water content.