Get to know your soil

Photos of the 2017-2018 Agronomy in the Field cohort for Central Iowa at the ISU Field Extension Education Lab. Photos by Hanna Bates.

An education in soil sampling

Last week I attended Agronomy in the Field, led by Angie Reick-Hinz, an ISU field agronomist.  The workshop focused on soil sampling out in a field. The cohort learned a lot of valuable insight into not only the science of soil sampling, but also practical knowledge from out-in-the-field experiences.

Taking soil samples in a field is critical in making decisions about fertilizer, manure, and limestone application rates. Both over and under application can reduce profits, so the best decision a farmer can make is based on a representative sample that accurately shows differences across his/her fields.

What do you need?

  • Sample bags
  • Field map
  • Soil probe
  • Bucket

When do you sample?

After harvest or before spring/fall fertilization times. Sampling should not occur immediately after lime, fertilizer, or manure application or when soil is excessively wet.

Where do you sample?

Samples taken from a field should represent a soil area that is under the same type of field cultivation and nutrient management. According to ISU Extension, the “choice of sample areas is determined by the soils present, past management and productivity, and goals desired for field management practices.”* See ISU Extension resources for maps and examples for where in the field to take samples.

Most importantly…

Like with everything that happens out in the field, it is important to keep records on soil testing so that you can evaluate change over time and the efficiency of fertilizer programs. As we say at the Iowa Water Center, the more data, the better! The more we learn about the soils, the better we can protect and enhance them. Healthy soils stay in place in a field and promote better crop growth by keeping nutrients where they belong during rain events. Not only can we monitor soil from the ground with farmers, but with The Daily Erosion Project. These combined resources, with others, can provide the best guidance in growing the best crop and protecting natural resources.

Interested in Agronomy in the Field? Contact Angie Rieck-Hinz at amrieck@iastate.edu or 515-231-2830 to be placed on a contact list.

* Sawyer, John, Mallarino, Antonio, and Randy Killorn. 2004. Take a Good Soil Sample to Help Make Good Decisions. Iowa State University Extension PM 287. Link: https://crops.extension.iastate.edu/files/article/PM287.pdf

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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. 
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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.

Soil – Agriculture’s Reservoir

Post submitted by Hanna Bates, Program Assistant for the Iowa Water Center

The soil is like a sponge that holds water so it is available when crops need it. Wetter soil at the surface prevents deeper infiltration and so water is lost as surface runoff. Not only this, but soil moisture is also a variable that influences the timing and amount of precipitation in a given area. This is due to the impact it has on the water cycle. This cycle circulates moisture from the ground through evaporation and plant transpiration to the atmosphere and back to the ground again through precipitation. Therefore, the amount of water stored in the soil can affect the amount of precipitation received during the growing season.

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Satellite imaging from the European Space Agency. The center figure depicts imaging derived from SMOS.

According to Hornbuckle (2014), “we enter each growing season ‘blind’ as to whether or not there will be enough soil moisture and precipitation to support productive crops.” If there were a way to document and record water storage in the soil besides field measurements, we would have a better ability to predict future weather patterns and therefore, make better field decisions. Satellite remote sensing tools such as the European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) and NASA’s Moisture Active Passive (SMAP) can be used to take such measurements. Before these tools can be used to estimate water storage and improve weather and climate predictions, researchers must compare them to what is actually measured within the soil. This process of confirming accuracy of a tool is called validation.

A project led by Dr. Brian Hornbuckle, and funded by the Iowa Water Center in 2014, sought to improve and validate SMOS and SMAP in near-surface soil moisture observations of Iowa. Hornbuckle used a network of soil moisture measurements located in the South Fork Watershed as a standard to validate the accuracy of SMOS and SMAP. At each site, soil moisture and precipitation was measured.

Some of the results of this research project are presented in a 2015 article published in the Journal of Hydrometeorology.  Rondinelli et al. found that SMOS and the network of soil moisture measurements detect different layers of the soil. SMOS takes measurements of the soil surface while the network observes a deeper level of soil. These results will allow scientists to better evaluate the accuracy of measurements from SMOS and SMAP and ultimately enhance our understanding of the water content of the soil surface.  As noted earlier, it is this layer of the soil that determines how much precipitation is lost to surface runoff.

In a subsequent study published in 2016, Hornbuckle et al. published further results that indicate new ways of using SMOS. Researchers found that SMOS can be used to look at water in vegetation, as opposed to water in the soil.  Hence SMOS might be used in the future to observe the growth and development of crops, and perhaps estimate yield and the time of harvest as opposed to conducting field surveys from the ground. It also has the potential to measure estimates of the biomass produced during the growing season, which could be useful to reach bioenergy production goals.

Research like this demonstrates that a single tool can be used in multiple ways to better understand our landscape. Not only this, but preliminary studies of SMOS also show that it is important to verify the accuracy of tools before relying on them. Like all research, the work is not done to identify all the potential uses for SMOS and SMAP.  A new NASA grant, in partnership with the Iowa Flood Center, will help get researchers even closer to making satellite measurements a useful, scientific tool to understand water near the soil surface.

References

Hornbuckle, Brian K. “New Satellites for Soil Moisture: Good for Iowans!.” A Letter from the Soil & Water Conservation Club President (2014): 20.

Hornbuckle, Brian K. Jason C. Patton, Andy VanLoocke, Andrew E. Suyker, Matthew C. Roby, Victoria A. Walker, Eswar R Iyer, Daryl E. Herzmann, and Erik A. Endacott. 2016. SMOS optical thickness changes in response to the growth and development of crops, crop management, and weather. Remote Sensing Environment (180) 320-333.

Rondinelli, Wesley J., Brian K. Hornbuckle, Jason C. Patton, Michael H. Cosh, Victoria A. Walker, Benjamin D. Carr, Sally D. Logsdon. 2015. Different Rates of Soil Drying after Rainfall Are Observed by the SMOS Satellite and the South Fork in situ Soil Moisture Network. Journal of Hydrometeorology. April 2015.

 

Planning for Watershed Success in Eastern Iowa

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Attendees of the Indian Creek Watershed open house discussing the map of the watershed. Photo from the Indian Creek Watershed Facebook page.

Post edited by Hanna Bates, Program Assistant at the Iowa Water Center

This week, we chatted with Jennifer Fencl, the Solid Waste & Environmental Services Director at The East Central Iowa Council of Governments (ECICOG). Fencl works to bring eastern Iowa stakeholders together to better manage their natural resources and to create a long-term investment in their community. Below are a few highlights from our conversation that outlines some of the behind-the-scenes work in watershed planning.

Please describe your work in watershed management in Iowa.

The East Central Iowa Council of Governments (ECICOG) became involved in watershed management in 2011 when the City of Marion requested assistance in applying for Watershed Management Authority Formation grant funding from the Iowa Economic Development Authority (IEDA) for the Indian Creek watershed. The Indian Creek Watershed Management Authority (ICWMA) was formed under Iowa Code 28E and 466B in August 2012 with 6 of the 7 eligible jurisdictions agreeing to plan for improvements on a watershed level. Funds were made available in 2013 by the IEDA to complete watershed management plans to address flood risk mitigation and water quality. The ICWMA received one of the three planning grants and engaged in a multi-jurisdictional planning approach facilitated by ECICOG in partnership with several local, state, and federal agencies. The resulting Indian Creek Watershed Management Plan (ICWM Plan) identifies strategies and recommendations for stormwater management and water quality protection, including specific implementation activities and milestones. The ICWM Plan was completed and presented to the public in June 2015 and adopted by all six of the ICWMA members at policy maker meetings during July and August of 2015.

As the ICWMA Plan was wrapping up, the City of Coralville requested ECICOG’s assistance in forming a WMA for the Clear Creek watershed. In this case, Coralville was willing to sponsor the WMA formation and planning grant application services. The Clear Creek Watershed Coalition (CCWC) formed as a WMA under Iowa Code 28E and 466B in October 2015 with all 9 of the eligible jurisdictions joining. ECICOG secured DNR watershed planning funds early in 2016 and the CCWC is mid-way through their planning process. Fortunately, the Clear Creek watershed was one of the eight watersheds selected for the Iowa Watershed Approach HUD grant project. The additional watershed planning funds from the HUD grant will add significantly to the resulting watershed plan.

In early 2016, the Middle Cedar Watershed Management Authority (MCWMA) was on its way to formally becoming a WMA and needed some help in completing the agreement filing, developing by-laws, and organizing the Board of Directors. ECICOG assisted the MCWMA in forming under Iowa Code 28E and 466B in June 2016 with 25 of the 65 eligible jurisdictions joining. The MCWMA is one of the eight watersheds selected for the Iowa Watershed Approach HUD grant project.

What are the challenges and rewards in doing work with watershed management?

One challenge that became clear in the Indian Creek process was the disconnect between the watershed (technical) assessment and the local stakeholders. That gap must be bridged to develop meaningful, locally-based goals and implementation strategies.  For me, the reward is watching the interaction between perceived “enemies” (urban/rural; big city/suburb; ag producer/government type) and bringing skeptical people into the process to develop an actual plan… that they ultimately agree to.

What kinds of stakeholders are involved in developing a watershed management plan?

It is critical to include the local Soil and Water Conservation District, government representatives, and the landowners (both urban & rural, flood impacted if possible) in developing goals and strategies. I believe that it is also important to identify the ‘experts’ in your watershed, both locally and from state agencies, early on and have them provide input on what assessment activities and planning services are really needed from an outside consultant. There is a role for everyone to play.

What are the basic steps in putting together a watershed management plan?

Here is my road map:

  1. Invite participation
  2. Identify resource concerns
  3. Assemble experts
  4. Complete assessment work
  5. Present the assessment to a broad list of stakeholders (need good interpreters)
  6. Develop goals, define implementation strategies, and prioritize the strategies
  7. Compile the plan and present the plan for comment
  8. Shop the plan for formal adoption by policy making board/councils.

What is one piece of advice you’d give to those wanting to develop a watershed plan for their community?

Run… kidding, sorta.  Seek help from the Iowa Department of Natural Resources and Iowa Department of Agriculture and Land Stewardship basin coordinators first, and then gauge the interest of the other entities in the watershed. You need to find some champions to help smooth the way for local elected officials.

Daily Erosion Project goes International

This week Dr. Richard Cruse, Professor in Agronomy at Iowa State University and Director of the Iowa Water Center, was invited to speak at the Rendez-vous végétal 2017 in Quebec, Canada. He provided a presentation on the cost of soil erosion and introduced the Daily Erosion Project to an international audience of soil and water professionals.

Below is an article published in le Bulletin des agriculteurs, a publication on new agricultural technologies in Quebec.  The article is written by Nicolas Mesy, an agronomist and freelance reporter and photographer. Topics the article explores include soil loss in Iowa, the science behind the Daily Erosion Project, and how soil erosion assessments can be a tool in decision-making.

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Introducing the Iowa Watershed Approach

Post originally appeared on the Iowa Learning Farms website

Today’s guest post was provided by Adam Wilke ISU Extension and Outreach Water Specialist.

The Iowa Watershed Approach (IWA) is a new five-year project focused on addressing factors associated with flood disasters in the state of Iowa. The IWA project will also provide benefits of improved water quality by implementing conservation practices outlined in the Iowa Nutrient Reduction Strategy.

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Assessing Cedar River flood waters, September 2016. Photo courtesy Brian Powers/DSM Register

The “HUD Project,” as it is commonly referred, was awarded $96.9 million by the U.S. Department of Housing and Urban Development (HUD). The National Disaster Resilience Competition provided $1 billion to communities that have experienced recent significant natural disasters, including Iowa’s three flood-related Presidential Disaster Declarations in 2013. Iowans remember the devastating floods of 2008 and 1993, and some are still working to repair damage from September 2016 flooding.

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Map of the Iowa Watershed Approach. Courtesy of Iowa Flood Center.

The IWA focuses on nine watersheds throughout the state, representing varying soil types, topographic regions, and land uses. These watersheds were prioritized as regions that have been most impacted and distressed from previous flood events and have unmet recovery needs. The IWA is a vision for both rural and urban resilience, and three cities (Storm Lake, Coralville, and Dubuque) are priority areas for the project.

Previous efforts to address flooding impacts were piloted through the Iowa Watersheds Project in five watersheds throughout the state in 2010. By 2016, over 65 constructed practices—such as ponds, wetlands, and terraces—have been completed.

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Road damage from Cedar River flood, June 2008. Courtesy Iowa Dept. of Transportation

The theme of year one is “The Iowa Watershed Approach: A Visions for Iowa’s Future Under Changing Hydrologic Conditions.” Climate science indicates that annual average precipitation in Iowa has trended upward over the last 100 years and extreme precipitation events (more than 1.25 inches per day) have increased throughout the state. University of Iowa research of 774 U.S. Geological Survey stream gauges found an upward trend in frequency of flooding throughout the Central U.S. over the past 50 years. This has contributed to crop loss and destruction of infrastructure, such as homes, roads, and bridges.

The IWA will work to achieve six specific outcomes:

  1. Reduce flood risk
  2. Improve water quality
  3. Increase flood resilience
  4. Engage stakeholders through collaboration and outreach/education
  5. Improve quality of life and health, especially for susceptible populations
  6. Develop a program that is scalable and replicable throughout the Midwest and the United States

The IWA focuses on innovative in-field and edge-of-field practices to reduce flood potential and decrease nutrient concentration in surface water. The practices include:

• Wetland Construction                              • Farm Ponds
• Storm Water Detention Basins              • Terraces
• Sediment Detention Basins                    • Floodplain Restoration
• Channel Bank Stabilization                    • Buffer Strips
• Saturated Buffers                                       • Perennial Cover
• Oxbow Restoration                                     • Bioreactors
• Prairie STRIPS

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Courtesy ISU Extension and Outreach. 

The IWA project creates Watershed Management Authorities (WMA) and these organizations allow for a broad range of stakeholders—including scientists, state agencies, counties, municipalities, farmers, and citizens—to organize and work towards the common goals of flood reduction and water quality improvement. Some watersheds, such as the Middle Cedar, have established WMAs, while others are beginning the formation process.

Stream gauges will provide data for the Iowa Flood Center to conduct hydrological assessments in each watershed and allow researchers to assess risks associated with flooding and water quality, including developing and evaluating future scenarios to maximize results from project resources.

WMA will use these findings to best select eligible subwatersheds at the HUC 12 (Hydrologic Unit Code) scale and prioritize implementation of constructed projects. Stakeholder inputs, watershed plans, and hydrological assessments will guide the WMAs in selecting the most beneficial practices and appropriate locations.

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Courtesy ISU Extension and Outreach.

This project combines the strengths and efforts of Iowa State University Extension and Outreach, the Iowa Nutrient Research Center, and the Daily Erosion Project by the Iowa Water Center to achieve these goals. The IWA is a new way to think about the movement of water across the Iowa landscape. One of the most important pieces of completing such a large and complicated project is to ensure stakeholder engagement throughout the project. We look forward to hearing your questions, thoughts, and concerns as we all seek the common goal of reducing flood disaster and ensuring water quality for generations to come.

–Adam Wilke

Geographic Information Systems at Iowa State University

We “dig” the data…

Written by Hanna Bates, Program Assistant at the Iowa Water Center

Big data requires big software and big ideas. This can especially be  true when it comes to managing our water-related resources. Today, we have access to numerous data points about our soil and water that can assist in understanding current landscape conditions and to plan for the future. Information such as this is not useful unless it can be analyzed by the experts using software such as Geographic Information Systems (GIS).

Recently, Inside Iowa State published a story regarding the geographic information systems support and research facility located on the Iowa State University campus. This facility provides a myriad of resources for teaching and tools related to using GIS for mapping and analyzing data. This facility not only trains students and provides extension services, but is also making an impact on “groundbreaking” research. Knowledge can be a powerful tool not only in enabling better policy and practices, but to inspire researchers to tackle innovative projects.

Work associated with the facility is The Daily Erosion Project. This is a research project housed within the Iowa Water Center and is driven by vast amounts of natural science information for better assessment of our soil. This research endeavor uses a multitude of data sources, including soil types, hill slopes, daily precipitation, and other data points to estimate soil movement and water runoff from the rolling hills of Iowa on a daily basis. All of this information is processed and transformed by a team of scientists and analysts to enable better decision-making on land uses in the Midwest. You can read more about it from Dr. Richard Cruse here.

What can the Daily Erosion Project be used for, you ask?

Output from the tool can provide an inventory of soil loss at the watershed level, assess the potential for water storage capacity in the soil, and be used to identify sensitive areas to target the use of conservation practices.  As the project acquires more information and interest by the public, it is expanding. Currently, the tool is growing to provide assessments in Minnesota, Kansas, Wisconsin, Nebraska, and Illinois.

Our landscapes are ever-changing. Because of this, it is energizing to see the tools and the talent at work through research facilities and solution-centered projects to tackle the critical problems we face in managing our soil and water resources.