A High Schooler's Perspective on Teaching and Learning Science: The Chinampa-in-a-Jar Activity

Who We Are

My name is Jose Luis Hernandez Pizano, I am a 10th grade student at Greenfield High School and I am from Jiquilpan, Michoacan, Mexico. I come from a family who’ve been working as agricultural workers in the Salinas Valley of California for decades now. I live in Greenfield, CA, also known as the heart of the Salinas Valley to many locals here.

My partner in this project is Angel Millard-Bruzos. He is an electrical engineering senior at Stanford University interning with the Greenfield Community Science Workshop this summer. With a passion for integrating electrical and mechanical engineering, he has been involved in various projects that bridge technology and community outreach. His work focuses on designing creative solutions, including our recent effort in developing an educational aquaponics exhibit. Through this internship, he aims to inspire young minds and foster a deeper understanding of sustainable practices.

 

Chinampa-in-a-jar activity being taught in a classroom

Planning and Preparation

To begin our work with the Greenfield Community Science Workshop (GCSW), we connected with our internship mentor, Callie Chappell. With Callie, we discussed ways of ensuring the best use of our time with an ultimate goal of reaching as many community members as possible. Our attention turned to an activity previously run in the BioJam Summer Camp hosted in the Salinas valley annually, the “chinampa-in-a-jar” activity. I attended this camp in 2023 and recall this activity being particularly impactful. Angel and I talked withCallie about the chinampa-in-a-jar and how we could repeat it for elementary school students attending summer school and the GCSW community. Before moving forward with this plan, Callie put Angel and I in touch with the original organizers of this activity, Melissa Ortiz and Rolando Perez, to ask for permission to modify and use their materials and to ask for how they wished to be recognized for their work. Callie let us know that we got the permission to go ahead with running the activity ourselves.

 

Introductory slide in slide deck used for BioJam activity

Developing and Sourcing Materials

For the educational background materials of the activity, in slideshows we made Angel and I gave attributions to the works of Rolando Perez, Melissa Ortiz, BioJam Camp, and the organization Xinampa. We proceeded to order jars and pumps from the original lesson plan that was used in BioJam. We then drafted a 2 week flowing curriculum planned for two separate 45 minute sessions. For sourcing materials, we relied on contacts who donated supplies to BioJam in the past and who assisted in making the original lesson plans.

 

List of supplies needed for chinampa-in-a-jar activity ran in BioJam

Neither Angel nor I had previously worked on lesson plans that required references to governmental educational standards, so we talked to Callie about standards and how to collaborate with teachers to meet them. We researched the appropriate standards for our age range, 5th and 6th graders, and modified the lesson plan accordingly. With foundational materials firmly in place, Angel and I started planning what we aimed to do for the first summer school session and how we were going to present material to the students. From my previous experience, I recalled how the chinampa-in-a-jar activity was impactful due to both the scientific and cultural context provided in camp. Angel and I wanted to make sure we still connected the activity to the background of aquaponics being used in ancient Aztec communities and how these farming practices can be and are being modernized for current day use.

 

Lesson plan heading for chinampa-in-a-jar activity

We decided that we wanted to work on the construction of the chinampa-in-a-jar in the second class session so we brainstormed ideas for educational activities that we could run in the first class session. We came up with several different activities for the first session, and kept in mind that we wanted to have backup activities ready to use in case anything were to fail or happen unexpectedly before we ran the sessions.

As we went through activities we had drafted, one stood out. We landed on a comparison poster activity that asked students to compare the historical aquaponics and modern aquaponics. To prepare for making a comparison poster activity engaging and impactful, Angel and I worked on modifying the slide deck previously used to present in BioJam. We modified the slides to a fifth graders comprehension level. For the first session, in detail, we planned to introduce the nitrogen cycle to the students and give instructions for the comparison poster activity they were doing with our slides. Next, we would provide some historical context about chinampas, a method of aquaponics farming that was widely used by Aztecs in parts of modern-day Mexico. Then, we would hand out all the materials that were needed for the students to cut and glue. On one side, preferably, the students would put the ancient farming practice (chinampas) and the modern practices (aquaponics) on the other side.

 

Work in progress comparison poster

We then met with José Sanchez, our supervisor at the GCSW, and Chacon, another employee of the GCSW, for feedback. We talked in detail about various technicalities, such as the summer school schedule, sourcing of materials, and logistics of travel. Working with José Sanchez and Chacon, we learned that to run the activity with all ~60 5th and 6th graders, we would need to reduce the cost of the chinampa materials per student. With José Sanchez’s and Chacon’s expertise, we decided to switch to cheaper pumps and containers to reduce our 2 largest costs.

Pet Fun is a pet shop locally owned in Salinas, CA, that has supplied snails and elodea (a plant that the snails eat) to the BioJam Camp for many years now. Angel coordinated with Josh at the Pet Fun store in Salinas to have snails donated for the aquaponics activity. We wish to thank Josh and the entire Pet Fun store for their generous donation of over 200 snails!

 

Bag of donated small marine snails

We returned any pumps and mason jars that we originally ordered and instead ordered the cheaper materials we decided on for the chinampa-in-a-jar activity from online retailers such as Temu. Angel also picked up extra materials, such as clay pebbles, netted pots, and rock pebbles, from Michelle Ortiz from the last time this activity was ran in BioJam.

 

Chinampa-in-a-jar from BioJam

Relying on another established contact for donations, Angel coordinated with Tanimura & Antle in Salinas to have plants donated for the aquaponics activity. We want to thank Abel Valdez and the entire Tanimura & Antle organization for their generous donation of ~400 romaine lettuce sprouts!

 

Romaine lettuce sprouts donated by Tanimura & Antle

To finalize our game plan, Angel and I met with the usual science teachers, Alfonso and Bobbie Joe, to get their final feedback on the curriculum, educational standards, and back up activities we had collectively planned. With their comments, we finished lesson materials for both sessions and prepared for the weeks ahead. The foundational materials we created (the lesson plans for the two days and list of materials with cost estimates) can be used by the GCSW in the future to rerun the activity.

Preparing to Teach

To prepare for teaching the activity, I brushed up on the Nitrogen Cycle so that I could teach it properly. This was my first experience as an instructor so I practiced explaining the nitrogen cycle. I researched the nitrogen cycle and learned how to explain it in a 5th and 6th grade friendly way. Here’s the steps I decided to use to educate the students:

1. Nitrogen starts up in the atmosphere.

2. The nitrogen is collected by the water droplets that make up clouds.

3. The nitrogen falls down through precipitation into the soil

4. The roots of any plant in the soil receives the nitrogen with the help of nitrifying bacteria

5. The plants make leaves or fruit that an animal consumes

6. The animal will either poop, pee, or die, and decomposers such as mushrooms will decompose that matter with the help of denitrifying bacteria and will repurpose any nitrogen that’s existing back into the nitrogen cycle.

So, in total, there’s six steps: 1. Nitrogen Fixation, 2. Nitrification, 3. Ammonification, 4. Assimilation, 5. Denitrification, 6. Nitrogen mineralization.

Angel and I then reconnected with Bobbie Joe and Alfonso and finished planning materials for the first session. Angel printed out the pictures and terms for the students to cut, as well as definitions for them to reference. We were now ready to teach the fifth and sixth grade classes.

Running the Sessions

Unfortunately, upon arriving at Frank Ledesma Elementary School, we learned that the classroom that we had been assigned to teach the science activity in did not have a projector, so we had to abandon our slide deck. Hence, we relied on only verbal instruction.

 

The classroom used for teaching

These classes were of various fifth and sixth graders. Angel and I taught the students many different things, such as the nitrogen cycle, how the Salinas valley was once wetlands, and the importance of water usage. We taught how the first chinampas have been recorded dating back to 1150 to 1350 CE. Chinampas were used primarily in Lakes Xochimilco and Chalco. I explained how chinampas use a different method of the nitrogen cycle, as the nitrogen is self contained within the plant/marine life ecosystem. Any aquatic organism living in the water underneath the chinampa supplies nitrogen/ammonia through their waste and the roots of the plants absorb the nitrates in the water and clean the water for the organisms to live in.

I took the lead in teaching, with occasional interjections by Angel. After teaching was done for the day, Alfonso, Angel, and I had a talk on what went well and what could’ve improved for future class sessions.

 

Angel sitting with students as they create their posters

I then began writing this Lab Note while Angel submitted a preliminary report to the fellowship through which his summer funding came. Angel and I revised plans for the second day of teaching with the constructive discussion in mind. In preparation for the second week of class, Angel picked up the snails and elodea from Pet Fun, and the romaine lettuce sprouts from Tanimura & Antle. We then set up an enclosure for the snails until they could be used in class.

 

Snails and elodea in holding tank

We prepared the plastic containers for the aquaponics activity with the help of Omar at the GCSW, who drilled holes in the plastic lids for netted pots to be inserted in.

 

Lid of plastic jar with a hole drilled for a netted pot

Upon arriving at the elementary school for the second day of teaching, Angel and I, along with the help of Daisy, Alfonso, and Bobbie Joe of the GCSW, set up the materials for the day, including lettuce plants on a tray to hand out to students, easily accessible water to fill students’ jars, and plans to disperse clay pebbles, rock pebbles, netted pots, plastic jars, pumps, and living components.

 

Lettuce plants set up on tray for handing out

To begin the class sessions I reminded students of the historical and scientific background of aquaponics and why we were running this activity. We then handed out plastic containers, lids, netted pots, and pumps, the basic materials needed to start the activity. I led the students through crafting their chinampas step-by-step in front of the classroom. First, students assembled their pumps by connecting the pump to a tube and an airstone, a filter for oxygenating the water.

 

Assembled pump and airstone with wall charger

Students were then handed out pebbles for the bottom of their chinampa. We also gave the students water, enough water so that the bottom of their netted pots would be submerged when the lid was eventually put on.

 

Jose Luis handing out rock pebbles to students

For the living aspects of the chinampas (plants and animals), students were handed out their lettuce sprouts still in their cloth packing and removed the packing. Students then placed their netted pot into the lid’s hole, placed their plant into the pot, and were given clay pebbles to fill in space within the netted pot.

 

Students removing the cloth wrapping around their lettuce sprouts

Angel then went around and handed out snails. Students were instructed again on the science of aquaponics and the nitrogen cycle. They relearned the basics of aquaponics, such as how they use just water, marine life, and plants to more sustainably farm.

 

Angel hands out snails

Students were given directions on how to take care of their new chinampa-in-a-jar properly: seek out indirect sunlight, give food to your snails about once a week or when food runs out, run your pump for at least a few hours a day, and in general be gentle with your plant. We then said goodbye as we sent students home with their new mini farms.

 

Student made chinampas

 

Modified plastic chinampa-in-a-jar

Reflection

Throughout all of this, I’ve learned that teaching is one valuable skill that every individual should experience. Teaching can provide a person with a sense of time management and confidence in their own abilities.

Also, I have learned that having a well organized list on what you’re going to do for anything that has to be planned is very helpful. There have been times where I’ve needed to plan for things, such as packing for a trip; I wasn’t very organized, so when I would need an object,for example a piece of clothing for an event, I wouldn’t have it. I found that running a classroom was very similar; if I didn’t plan well, I wouldn’t be able to teach.

As for the science behind chinampas, I learned that aquaponics has taken a tremendous amount of time to develop. I had previously been a student of this activity, but teaching it has shown me more in-depth details as to what really happens behind the scenes in the aquaponics world.

Personally, it was difficult and time consuming to simplify the nitrogen cycle for me, but it was worth it all in the end. It was difficult because organizing all the terminology and descriptions of how the cycle flows into a comprehensible level for 5th graders did not come naturally to me. Being a student you learn, obviously, but as an instructor you do so many things to make sure other people learn, that you really develop a handle on all of the concepts you wouldn’t normally.

As you’ve read this lab note I hope you got a clear picture of what we did to run this activity. I hope to continue learning science going forward in the future, and with science I want to experiment, develop new biotech, and collaborate with my peers to create a better future for agricultural workers! Angel and I plan to continue working with the Greenfield Community Science Workshop this summer as we build a larger educational “chinampa-in-a-tank” exhibit.

 

Angel (left) and Jose Luis (right) outside of Frank Ledesma Elementary School

We would like to extend deep gratitude to everyone that helped us make running possible, including Melissa Ortiz and BioJam, Rolando Perez and Xinampa, Callie Chappell, José Sanchez, Fabian "Chacon" Chacon, Bobbie Joe, Alfonso, Daisy, Omar, Josh and Pet Fun, Abel Valdez and Tanimura & Antle, and many more.