Students apply the Law of Conservation of Mass to understand nitrogen (N) budgets for a Corn-belt agricultural system at the plot level. A 45-minute, in-class introduction enables students to complete an outside-of-class activity using a process-based simulation model in "lab mode" address "What-If" questions about effects of various management practices on N cycling. Then, during one 75-minute class, teams use the model in a game-like mode to compete in attaining four different goals: 1) Maximize income; 2) Increase soil carbon; 3) Reduce nitrate flow to streams; and 4) Optimize yield and soil organic N while reducing N in streams.
Ann E. Russell1 and James K. Dailey2
1Department of Natural Resource Ecology & Management, Iowa State University, Ames, IA 50011
2James Dailey and Associates, 1695 Kerry Lane, Woodbury, MN 55125
Corresponding author: Ann Russell, firstname.lastname@example.org
120 minutes total; 45 minutes introduction to the individual activity during one class period, then 75 minutes during the next class meeting time.
OUTSIDE OF CLASS TIME
For the individual activity done outside of class, students will complete the tables in the handout, based on data collected from their model runs and interpret the results in words. For the team-based part of the activity, they will fill in data in the tables in the handouts, based on their model runs. During a class-wide discussion at the end, students will discuss their reasoning for the management practices they selected for modeling, and the implications for regional issues, such as hypoxia in the Gulf of Mexico.
Because this is a simulation modeling activity, it can be done anywhere indoors. They will need the internet to download the model at the beginning, but once it is on their laptop, they can work anywhere.
This can be used in any Introductory Biology or Introductory Ecology course, or even more advanced courses because this topic is often not covered in introductory courses. It can be used in a lecture or a laboratory section of a course. The activity works best after the topic of biogeochemical cycles has been covered. I have used this for courses of 6 to 80 students.
I have used this in three different courses at a large, public university.
The simulation model was designed to be very user friendly, and the home website is equipped with an introductory video, with the goal of making the activity accessible for non-majors and pre-college students. The video has closed captioning. While the setting is midwestern-US centric, element budgeting is a broad concept that can be transferred to any ecosystem. As long as internet access is available, this activity is accessible.
Description of other Resource Files:
My guiding inspiration is from H.T. Odum. It has been a while since he passed away, but his creative spirit continues to be a daily source of inspiration that the world is a dynamic place - and it's fun to model it. Without the talents and patience of Jim Dailey, my ideas would never have reached fruition, however. We also thank our collaborators, Mike Castellano, Matt Helmers, Tom Isenhart, Lisa Schulte-Moore, and Richard Schultz for their guidance about data for the model and feedback. We also thank Ann Greazel and John Van Dyke for the website development and Mike Castellano for peer review. Funding for this project was provided by ISU's College of Agriculture & Life Sciences Technical Advancement Committee, ISU's Department of Natural Resource Ecology & Management, and the NIFA Multistate Project No. NC1195.
Ann E. Russell and James K. Dailey. 7 July 2020, posting date. Gaming Ag Nitrogen Cycling Teaching Issues and Experiments in Ecology, Vol. 16: Experiment #2 [online]. https://tiee.esa.org/vol/v16/experiments/russell/abstract.html
Schematic of Nitrogen Modelfull size image