Lost in the Corn: The Search for Lysimeters

Today’s guest blog post was provided by summer student intern Laura Lacquement. A native Iowan, Laura grew up south of Des Moines, and went to school at Martensdale-St. Mary’s. She started her college career at Valparaiso University, and later transferred to ISU, where she is now a senior studying Environmental Science.  


I enjoy travelling across the State of Iowa with Water Rocks! and Iowa Learning Farms. The location and events vary, while the field work remains consistent. One of the projects I’ve helped with all summer long is ILF’s cover crop mixtures project. Each week we travel to three of Iowa State University’s research farms to collect water samples from lysimeters located in plots of corn and soybeans.  Each block of plots contains 12 lysimeters placed between rows of corn or soybeans.

Lysimeters measure the movement or storage of water in the ground.  The lysimeters that the ILF team uses are composed of a tube two inches in diameter and two feet (24”) deep.  The bottom of the tube is composed of a porous ceramic cup that allows the movement of water into the lysimeter from the soil around it. Using a vacuum pump, we create suction inside the tube that pulls water inside.  Each week, we extract the water by using a flask that is connected to the vacuum pump on one side and a straw connected to its lid and inserted into the tube to its full depth.  Using the pump and flask, we pull water from the lysimeter into a small bottle, where it will later be analyzed for the amount of nitrates present. Each lysimeter tube is installed so it’s flush with the ground. To protect the lysimeter, a four inch PVC drainage pipe plug and small pipe is placed above it.

Most of our plots are located close to each other, with the exception of the plots at the ISU Northern Research and Demonstration Farm in Kanawha, Iowa. Finding the lysimeters there can be quite an adventure! At the start of the internship, all we could see of corn and soybeans in our plots were little sprouts an inch tall.  In just a couple weeks, the corn grew past our knees to over our heads.  I not only watched this growth, but experienced it firsthand by struggling to carry our devices and tools over and through the corn and soybeans to each lysimeter.

On Friday, June 30, I traveled to Kanawha, Iowa, with Elizabeth to extract water samples from lysimeters there. As I mentioned, the plots here are not located right next to each other, but in completely different fields separated by a grass driveway.  After we collected samples from the soybeans, we entered the corn in search of our small buried lysimeters in the shoulder-height corn.  We walked inside each row looking for our lysimeters … for an hour or so. Our ILF plots happen to be in the middle of a much larger field, and the challenge is that there’s no easy way to flag or label the plots once the corn is this tall! We eventually ventured a bit south of our current location, where we recognized our plots and finally spotted a lysimeter only a short distance away. Small victories!

Friday, July 7, I returned to Kanawha with Kaleb to collect more samples. This time, I knew exactly where to go to find the plot, but not the precise location of the lysimeters. In just one week, the corn had grown from the height of my shoulders to the height of me. I could no longer see over the corn.  As I finished extracting each water sample, Kaleb would move to the next lysimeter.  He may be the tallest of us interns, yet I still could not see him over the corn.  To find him and the next lysimeter, I followed the sound of corn rustling and looked for his bright red shirt through the corn.  If we do not wear bright colored shirts, a game of Marco Polo may be necessary!

After these experiences, I’m now very confident where ILF’s plots at Kanawha are located, plus how to find the other lysimeters and interns in corn taller than me. Each time I take samples from the lysimeters, I have learned a little more about corn and soybean cropping systems, as well as water quality issues in Iowa!

Laura Lacquement

Cover crops key to N retention + soil health, especially before soybeans

How can we increase nitrogen retention and soil health in Iowa’s corn and soybean cropping systems? There is not just one single quick fix, but Dr. Mike Castellano, William T. Frankenberger Professor of Soil Science and Associate Professor in the Department of Agronomy at Iowa State University, made the strong case for cover crops in last week’s Iowa Learning Farms webinar.

Castellano framed the webinar with a discussion of nitrogen budgets. As he put it, we don’t typically think about financial management without a budget – nutrient management is the same way! He then explored the potential of cover crops, especially cereal rye, to aid farmers in retaining nitrogen (via the cover crop plant biomass) and building soil organic matter. Watch the full archived webinar on the Iowa Learning Farms website: https://connect.extension.iastate.edu/p6kfk1qr4te/.

OR, if you’d like the CliffsNotes version, here are the Top 5 key take home points that jumped out at me…

cc-top5takehomepoints-iiAgain, you can check out the full presentation on the Webinar Archives page of the Iowa Learning Farms website.

Save the date…
The next Iowa Learning Farms webinar will be Wednesday, October 19 at 1:00 p.m., featuring our own Dr. Matt Helmers. He will be addressing common questions and misconceptions regarding cover crops, drainage, and more … think Mythbusters meets water quality! It’s sure to be a lively conversation.

Ann Staudt


Food for Thought

As Christmas is now in the past and we turn our minds to 2016, here is a provocative article published in the Washington Post: 10 Things We Should Do to Fix our Broken Food System. Check out the screen shot below for a sneak peek; clicking on the screen shot will take you to the full Washington Post article.

“In this end-of-the-year wrap-up, Tamar Haspel, a food writer for The Washington Post, lays out her 10 things we should do to change a broken food system – 10 changes she says could have a ripple effect, changes that would beget others. She begins with what the government could do: Develop a best-practices standard that could be codified and certified, so farmers who use best practices could attract customers willing to pay more for foods grown that way; Move to crop neutral insurance; Overhaul the Supplemental Nutrition Assistance Program so that it ensures Americans have access to healthful foods; and, Teach food in schools. Next, Haspel addresses what she would like to see food manufacturers do, which is a lot, but she confines herself to two: Use source as a selling point; and, Label everything. As for consumers, she says to vote with your wallet, get closer to food, and cook. Lastly, Haspel looks to farmers, and in this case, looks for a way to give farmers the help they might need to make changes, such as creating a market for crops and animals raised with attention to the rights of farmworkers, the welfare of animals, and the impact on the planet. And create a standard that allows them to charge more for products raised according to higher standards. On the flip side, she says, stop creating incentives for farmers to grow a few commodity crops at a large-scale, and with little thought to environmental repercussions. Finally, everyone, she says, needs to come to the table and engage in a more inclusive, constructive conversation.” – Article Summary by Meridian Institute

Happy New Year!

Jacqueline Comito

RESEARCH REPORT: Cereal Rye Cover Crop Termination Date Ahead of Soybeans

Original post written by Stefan Gailans, Practical Farmers of Iowa

Delaying cover crop termination until soybean planting would allow for more biomass production by the cover crop in the spring presenting the opportunity for more environmental benefit.

A newly released research report profiles the findings of farmer-cooperators who seeded soybeans 10-14 days after terminating a cereal rye cover crop and within 1 day of terminating the cover crop. The objective of this research project was to quantify the agronomic performance of soybeans planted following two cereal rye cover crop termination dates—which results in planting into different levels of cover crop residue.

You can read about it here: Cereal Rye Cover Crop Termination Date Ahead of Soybeans. The on-farm trials were conducted by Bob Lynch in 2014 and Jeremy Gustafson and Jack Boyer in 2015.

Photo credit – Practical Farmers of Iowa

Among the Key Findings:

  • Delaying cereal rye cover crop termination until within 1 day of seeding soybeans resulted in ~2x as much residue compared to when terminating 10-14 days prior to seeding soybeans.
  • Jeremy Gustafson and Jack Boyer saw no difference in soybean yields with the two cover crop termination dates while Bob Lynch saw a small reduction with the late termination date.
  • Bob and Jack observed cereal rye residue in the late termination treatment to persist through the soybean growing season holding soil in place and reducing weed pressure.
  • The most interesting part of the trial,” Jack says, “was the improved control of waterhemp in the cover areas versus the no covers. I get the impression, that with soybeans, you have considerable flexibility with termination date for the cover crop.” In the future, Jack plans on improving his no-till drill performance when seeding into high residue environments to improve soybean stands.
  • Based on the observations from his farm, Jeremy is convinced: “I plan to do more late termination of my cover crop ahead of soybeans.”

Support for this project was provided by the Walton Family Foundation and the Iowa Department of Agriculture and Land Stewardship – Division of Soil Conservation. The full report can be viewed here: Cereal Rye Cover Crop Termination Date Ahead of Soybeans

For more information about this study and other studies as part of PFI’s Cooperators’ Program, contact Stefan Gailans at stefan@practicalfarmers.org.

A Cover Crop Snapshot

In the last two weeks, Iowa Learning Farms team members have visited five of our cover crop demonstration sites located on ISU Research Farms to check on spring cover crop growth and prepare our suction lysimeters for water monitoring this spring.

I posted photos from my trip to the Armstrong Research Farm on March 27, but now that we’ve been to each site, I thought it would be interesting to see a snapshot of how our cover crops (specifically, the over-wintering cereal rye) are doing across the state.

Here are the pics in chronological order of our visits:






How are your cover crops doing this spring?  We’d love to see your spring cover crops photos… share with us on Facebook, Twitter, or send via email to ilf@iastate.edu.

Ann Staudt

Take the ROCK YOUR WATERSHED! Challenge

Rock Your Watershed! is a new interactive game on the Water Rocks! website (www.waterrocks.org) that challenges users to select land management practices for ten parcels of land in a shared watershed, while balancing profit (from agricultural crop production) and water quality parameters (sediment, nitrogen, and phosphorus).   Profit and water quality parameters come together to yield an overall score, but precipitation each year is an unknown variable that can make a big difference!

The game’s algorithms are grounded in scientific studies correlating land management choices, sediment and nutrient transport, economics and precipitation in the state of Iowa.    It’s a fun (not to mention competitive) way to get Iowans thinking about the connections between land management choices and the health of our natural resources.

The first level of the Rock Your Watershed! game was debuted in November and was played 450 times in its first two weeks.  One 7th grader told us that he had to play the game 17 times before he figured out where it made sense to place different practices for a good score. How’s that for engagement — how many 7th graders do you know that will sit through a textbook lesson 17 times?


You can find ROCK YOUR WATERSHED! in the left hand menu of the Water Rocks! website.  The game is computer, ipad- and tablet-friendly, as long as you have internet access.  Are you ready to take the Rock Your Watershed! challenge?    Try it today and see how your choices hold up!