Identifying Indicators for Soil Health

Breaking down our knowledge of soil enzymes

Post written by Marshall McDaniel, Assistant Professor in the Department of Agronomy at Iowa State University

As mentioned in a recent Washington Post article, there is a zoo beneath our feet in the soil. There are three properties of the soil, which are physical, chemical, and the biological properties. The emphasis on soil biology is, in large part, what separates soil health from the concepts of soil quality and the physical properties of soil (also known as soil tilth).  After all, only something that is living can be healthy (or unhealthy).  Many soil organisms are like us humans in that they require carbon as their main source of food in order to grow and reproduce.  Extracellular enzymes are proteins produced by microorganisms in soil to acquire carbon and nutrients from soil organic matter.

The McDaniel Lab was one of five to receive the Soil Health Literature and Information Review Grants from the Soil Health Institute. We will do a quantitative literature review on two of these enzymes – beta-glucosidase and polyphenol oxidase.  Beta-glucosidase can generally be thought of as being used for easily broken down, or labile, forms of soil carbon, and polyphenol oxidase for recalcitrant carbon.  In other words, think of labile carbon as a buffet of ‘yummy and healthy’ food that is nutritious and easy-to-digest for soil microbes, while recalcitrant carbon can be thought of as the equivalent of broccoli stems to human digestion.  We want to manage soils so that there is a large amount of the ‘yummy and healthy’ soil carbon for microbes to eat, and less of the ‘broccoli stems’.

Where the enzymes come in is that soil microbes will produce more of the beta-glucosidase enzyme if there is more ‘yummy and healthy’ forms of carbon in the soil, because it helps them to metabolize this form of carbon.  Conversely, if all you have left in the soil are ‘broccoli stems’, then as a soil microbe you are going to produce more polyphenol oxidase to metabolize this difficult to break down source of food.  Therefore, the ratio of these two enzymes holds promise as a good biological soil health indicator since it is an index of supply-and-demand for ‘yummy and healthy’ microbe food over ‘broccoli stems’.

What does this have to do with water?

Soil health and water quality go hand in hand. Improved soil health has the potential to increase water infiltration, increase water holding capacity, decrease surface runoff, decrease soil erosion, increase nutrient retention in the soil for plants, and more. By improving understanding of our soil biology, we can both better serve our natural resources and crop production.

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University of Iowa: A case study of flood response

 

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In honor of construction starting soon to replace one of the last University of Iowa buildings damaged by the 2008 floods, we have decided to highlight a history of flood infrastructure investments at the university .

Just one-year shy of a decade since the 2008 floods, the final plans have been approved for a new facility for the University of Iowa Museum of Art. Like Hancher Auditorium, the music school, the library, and the Iowa Memorial Union, among about seventeen other buildings (Connerly et al 2017), the art museum was a significant loss to the university that scattered its 14,000-estimated piece collection to new locations on and off campus.

According to Connerly et al 2017, damages and recovery were estimated to be $743 million and is the highest costing disaster recovery in Iowa. As a public institution located in a floodplain area, it has had a history of flood preparation and response since its inception in 1847. As their article explains, the flooding brought up many critical questions, including: “why did the University construct important new buildings, some of them iconic, within the floodplain?” and how can the university cope with future natural and human-made flooding?

To answer the first question, the university built where they did predominantly because they had few options. The risk of flood also gave the appearance of being manageable at the time and policies for flood mitigation and subsidies were more risky than they appeared to be (Connerly et al 2017). The university started on a small four block area east of the Iowa River. The university and the City of Iowa City grew concurrently causing buildings to be placed closer and closer to the river. In 1905, the university commissioned a master plan by the Olmsted Brothers that included riverfront property, but its use would only be for recreation and parks (Connerly et al 2017). Land acquisition advisement by the Olmsteds was illustrated in the following:

“The Olmsted Brothers emphasized the need to acquire land that would be of value to the University, even if it costs more. They stated, ‘‘the process of acquisition of additional land must evidently go on indefinitely, but some other motives than those of convenience and cheapness should be kept in mind and should often have more weight than those.” (55)

The construction on the floodplain started with the Iowa Memorial Union (IMU) in the 1920s and then grew to include the arts campus. Construction for a fine arts building was originally planned for a site north of the IMU, but an agreement could not be reached for a price. Instead, the campus was developed on acquired land that was a wetland formerly used as a city landfill by the river (Connerly et al 2017).

The wetlands were filled and the buildings were constructed to be above recorded flood level data available at the time and levees were constructed on the river. Later, these efforts included the university’s support of building the Coralville Reservoir by the Army Corps of Engineers, in which the president of the university at that time stated, “the Reservoir will make possible a program for the permanent development of the river front through the University campus” ( Connerly et al 2017, p.58). The campus was growing in two halves on the east and west side of the river. Development in-between would unite the two pieces, especially when considering there were little other places to build.

This culminates in the issue of what Connerly et al (2017) describes as the “safe development paradox.” This term is used to describe the federal support for levees, dams, disaster aid programs, and other assistance that spurred development in the floodplains. By providing a safety net with federal assisted water-related control, recovery, and insurance, federal policy enabled development that came at a cost with the 1993 and 2008 floods.

How can the university cope with natural and human-made flooding for the future?

To answer this question, the university has responded to the 2008 floods by re-purposing or completely rebuilding new facilities that are more resilient to withstanding future flooding using scientific modelling as a tool. The recovery efforts include a multitude of partnerships that choreograph their work around where FEMA compliance and insurance policies reach within each building. The university voluntarily chose to conduct a campus-wide flood mitigation strategy that is in progress. This strategy includes elevated sidewalks, supports for temporary flood walls, building pumping systems, and removable external walls. The university has also rebuilt two buildings away from their original locations. As seen above, these strategies have been tested with the rise in water levels in 2013.

In review, the tumultuous history of flooding infrastructure contains valuable lessons. Resilience, which is at the core of what public infrastructure is trying to achieve, is the ability to spring back from disasters. The university that came out on the other side of the 2008 floods is one that utilizes water research and technology using scientific methods and demonstrates that there is room for improvement in state and federal policies and procedures. As a result, when future flooding occurs, we will all be better able to respond.

Connerly, Charles, Laurian, Lucie, Throgmorton, James. 2017. Planning for Floods at the University of Iowa. Journal of Planning History 16(1): 50-73.

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Hanna Bates is the Program Assistant at the Iowa Water Center. She has a MS in Sociology and Sustainable Agriculture from Iowa State University. She is also an alumna of the University of Iowa for her undergraduate degree. 

Make a Suggestion for IWConf18

Recently, we announced the open call for presentations for the 2018 Iowa Water Conference. (There’s still time to submit your abstract – the deadline is September 4 at 11:59 p.m.!) We have had some great submissions thus far, and look forward to reviewing them with the Iowa Water Conference planning committee.

However, it occurred to us last week through some conversations at the Prairie Lakes Conference in Okoboji, IA that there may be a swath of good presentation suggestions sitting out there from people who wouldn’t want to volunteer other people (or themselves) without an invitation. While we ask for suggestions in the post-event evaluation, we historically have not actively solicited suggestions for speakers the rest of the year.

To solve this dilemma, we are introducing a new webform on the conference page on our website. Here, you can make suggestions of topics or speakers you’d like to see covered at the upcoming Iowa Water Conference. Keep in mind this is prime agenda developing season – we typically fill up the agenda by November 1 – so while we accept suggestions year-round, anything after the agenda is full will be considered for the following year.

Of course, you’re always welcome to chat with us as you see us out and about, or shoot an email directly to hbates@iastate.edu. Happy suggesting!

Summer Update from the IWC Graduate Student Research Grant Program: Emily Martin

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Post submitted by Emily Martin, MS Environmental Science student at Iowa State University

Intensive farming and heavy nutrient application in the Midwest coupled with an extensive subsurface tile drainage network frequently leads to excessive nutrients in surface waters. As a result, heavy amounts of nitrogen and phosphorus has become a critical issue for policy and water research.

In spring 2017, I was awarded funding in the Iowa Water Center Graduate Student Supplemental Research Competition for my project titled, “Enhancing phosphate removal in woodchip bioreactors.” This project is conducted under advisement of Dr. Michelle Soupir at Iowa State University. A bioreactor is a subsurface trench along the edge of the field that can be filled with a range of different carbon sources. They are identified as a practice to help mitigate nutrient loss to flowing water systems, and so they deserve further research to understand their full capacity to capture water nutrients.

The goal of the project is to evaluate the ability of woodchip bioreactors to remove phosphorous by adding biochar as a phosphate (P) amendment to bioreactors. Objectives of the study are (1) to assess the effectiveness of different amendments on P removal in bioreactors and (2) to analyze the effect of influent P on overall removal.

We broke the project down into two main parts: a P sorption study and a column study. We completed part one during the month of June using 18 different types of biochar. The biochar was made by Bernardo Del Campo at ARTichar using three different temperatures of slow pyrolysis, 400°C, 600°C, and 800°C. We used six different types of biomass provided by the BioCentury Research Farm and the City of Ames, which are: switchgrass, corn stover, ash trees, red oak, mixed pine, and loblolly pine. The goal was to test a variety of biomass to see which would perform best as a P amendment and under which pyrolysis conditions they would function best.

Biochar is made using a process called pyrolysis. Pyrolysis is the burning of plant materials in a low to no oxygen chamber in order to “activate” the carbon structures that exists naturally within plants. The highly structured form of carbon rings in plants is desired for its stability and potential to adsorb or bind with chemicals, including phosphate and nitrate. There are two main types of pyrolysis: fast and slow, which refers to the amount of time the biomass remains in the pyrolysis chamber. Fast pyrolysis can be used to create biochar, but the yield is lower than slow pyrolysis. The temperature of pyrolysis can impact how the biochar interacts with different chemicals. In order to test these effects, we used three different temperatures when making our biochar.

Results from the P sorption study showed a few patterns. The main take away is that none of the biochars we tested adsorbed P exceptionally well; however, of the biochars we tested, the following were our top five P adsorbers:

  1. Corn stover @ 800°C
  2. Loblolly pine @ 600°C
  3. Red oak @ 600°C
  4. Switch grass @ 800°C
  5. Mixed pine @ 400°C

Because none of the biochars performed well in our P sorption test, we had to make a decision for the second part of the project. We came up with two options: (1) find new biomass and run the P sorption test again, or (2) test how well all 18 biochars remove nitrate from water. We chose option two and have begun nitrate batch tests, which will run throughout July. The batch tests are being run in one liter flasks and are tested at 4, 8, 12, and 24 hours to simulate woodchip bioreactor residence times found in the field.

After the nitrate batch test is complete, we will analyze results and decide if we will move forward with option one and see how other biomasses perform in a P sorption test.

Check back later on to learn more about the progress of this project!

 

2018 Iowa Water Conference – Call for Abstracts!

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Success in water-related work, whether it is out in the farm field, a backyard, or in city infrastructure, cannot be achieved alone. It is done by a community and for a community. With that in mind, the Iowa Water Conference Planning Committee is happy to announce the theme for the 2018 Iowa Water Conference: “Our Watershed, Our Community.” This theme was inspired by the large, complex network of water-related professionals in Iowa that support local watershed work.

We invite water professionals, researchers, and graduate students to submit presentation abstracts centered around the theme of community in water. Through these presentations, applications should share success stories, challenges, and research that supports a foundation of community at the watershed-level.

The call for presentations, including instructions for submission, can be found here. Questions can be directed to Hanna Bates at hbates@iastate.edu. We look forward to learning about your watershed experience!

Project AWARE 2017

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 Photo of Cedar River Coalition partners. Photo from @IWAReduceFloods, the Twitter account for the Iowa Watershed Approach.

Getting Down and Dirty for Cleaner Iowa Rivers

Last week we participated in cleaning up an Iowa river alongside the Iowa Department of Natural Resources and other water partners across the state for Project AWARE. This event is a week-long outdoor expedition to clean up a selected Iowa river. The purpose of this event is to increase awareness of and engagement with Iowa’s public waters. It gives Iowans the opportunity to make a difference in water no matter who they are and what they do in the state. Participants have the opportunity to do the cleanup for one day or stay and camp the whole week.

This year, the event was held on the Cedar River in Mitchell and Floyd Counties from July 10-14. Hundreds of water partners and community members across the state joined for this year’s cleanup. We attended the fourth day of the event. Our starting point was about 19 miles up river from Charles City, Iowa. Once we arrived in Charles City, we had the opportunity to go inner tubing down the Charles City Whitewater course to the campsite to receive a t-shirt and join in on evening fun at the site.

While we only attended one day of the trip, we found many canoe-loads of trash that does not belong in a river, such as barrels, tires, and even a couch!

See photos below for the highlights!

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IWC Debuts New Logo

The Iowa Water Center is pleased to unveil our new logo!

It’s been five years since the Iowa Water Center last redesigned the logo, and it’s amazing how things have changed in that time. New staff, new projects, and a reinvigorated commitment to enhanced water management across the state have better defined our focus as originally laid out in the federal Water Resources Research Act (WRRA) of 1964.

Through this legislation, we are tasked with conducting a statewide research program that supports four critical needs on a local level:

  1. improvements in water supply reliability;
  2. the exploration of new ideas that address water problems or expand understanding of water and water-related phenomena;
  3. the entry of new research scientists, engineers, and technicians into water resources fields; and
  4. the dissemination of research results to water managers and the public.

We are also called to “cooperate closely with other colleges and universities in the State that have demonstrated capabilities for research, information dissemination, and graduate training in order to develop a statewide program designed to resolve State and regional water and related land problems.”

We don’t take these directives lightly. Through our conducted research, robust online presence, and role as a connector for collegiate and credible water-related agency and organization work, we strive to foster efficient, effective advances in water management for the state of Iowa. Every project we take on has to pass this test, so it is only fitting that our new logo symbolizes what we so highly value.

The water droplet, of course, is a familiar emblem for our industry. However, our water droplet takes subtle cues from an ear of corn to tie into Iowa’s agricultural roots. The four colors of the droplet represent those four critical needs defined in the WRRA. Additionally, these sections cross over and into each other, symbolizing the connective nature of our work. The font is a nod to our administrative home at Iowa State University.

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We look forward to our stakeholders becoming familiar with the new look as we also look to improve our website so that it better reflects our Center. We’d also like to give a special thank you to Zao525 for their expertise, attention to detail, and guidance in this process.