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Barnett (standing) in the Service Building on Middle Campus, with College Bound students planting their automated greenhouses. (Photo: Lee Pellegrini)

Watching a student stir a concoction of sodium alginate, phytagel, and deionized water in a Pyrex bowl with a kitchen stick blender, Mike Barnett says with a chuckle, “That’s what I use to make chocolate.”

Barnett is a professor in the Lynch School of Education (and a connoisseur of chocolate). Over the past eight years, he has worked with colleagues at LSOE and other institutions to develop a suite of curricular activities that provide middle and high school students with entry points into STEM (science, technology, engineering, and mathematics)—from science-focused theater productions to hydroponic farming—”without diluting the content,” he says. The 10 students working around him in a Higgins Hall classroom in mid-July, all wearing safety glasses and disposable latex gloves as they measure and mix materials, are ninth- and 10th-graders from the Boston Public Schools system. They are taking part in a pilot program with the bulky title “Seeding the Future of STEM through Emerging Agricultural Technologies.” Funded by a three-year, $1.2 million grant from the National Science Foundation, the program, of which Barnett is principal investigator and ever-present instigator, will involve young students in research on little-understood aspects of plant growth, using computer coding, miniature greenhouses, and a recently invented growing medium called transparent soil.

Transparent soil was developed in 2012 by plant scientists in Scotland. It consists of polymer beads about a quarter-inch in diameter or smaller (size can be varied to create more or less dense soil). The beads are made of commonly available chemicals (an important consideration for Barnett, who works with cash-strapped public schools) that are blended, heated, blended again, and then syringed slowly, drop by drop, into a jar to form—if all goes well—the small gelatinous orbs. If the mix is squirted out too rapidly, the result can be a slimy goo. “Like boogers,” said one student.

The porous beads very closely mimic the properties of regular soil—taking up nutrients and water, facilitating chemical reactions. They are naturally opaque, but with the addition of a refractive liquid, they become transparent, allowing researchers for the first time to observe the behavior of roots as they grow and encounter different conditions. Previously, to study the rhizosphere one had to pull a plant out of its soil—in other words, destroy it—or grow it in a hydroponic solution, which produces different growth patterns from those of soil-based plants. “It turns out,” Barnett says, “there’s a great deal we don’t know about how plants grow.”

Barnett learned about transparent soil in 2016 from Ludovico Cademartiri, an assistant professor of materials science and engineering at Iowa State University who was in Boston for a materials science conference. Cademartiri’s Ames, Iowa, lab is using the new medium to study the growth of soybeans, brassicas, and corn, looking at the roots’ responses to various environmental factors—elevated levels of carbon dioxide, for example, or drought. Barnett saw an opportunity to engage middle and high school students in “real, edgy science, a cool way to study something that’s not on the face of it that exciting.” As he told the group the day before they attempted to make their own transparent soil, “What you are going to do has never been done by high school students in this country or anywhere else.” A student exclaimed, “You mean, we’re scientists.”

The 19 high-school students working on the transparent soil project with Barnett and his team of six graduate students are part of College Bound, a University program that brings disadvantaged middle- and high-school students from Boston Public Schools to campus for pre-collegiate mentoring and skills development. Now in its 30th year, College Bound has since 2011 engaged students in STEM projects such as the aforementioned hydroponic farming and theater productions.

The College Bound students taking part in the transparent soil pilot were on campus during the last three weeks of July (dividing their days between the transparent soil work and related pre-collegiate mentoring). They were instructed by five Boston-area high school science teachers who had spent the first week of July with Barnett’s team, learning about coding, greenhouse growing, and transparent soil.

The students started by learning how to use the universal computing language Python to make a string of lights turn on and off, or change colors in time with the beat of a song. They would employ the same language—writing some 40 lines of code—to run the fans, lights, temperature and humidity sensors, and cam-driven vents that would monitor and regulate environmental conditions in the 9-x-15-inch plastic greenhouses.

The students arrived with little or no experience in computer science. “I thought coding was really boring, complicated stuff that only engineers did,” said Yarelis Mendez, a rising 10th grader at New Mission High School in Hyde Park. A number of her College Bound classmates commented that coding strained their patience. “You think you’ve done everything right, but the thing still doesn’t work,” said Mendez’s lab partner, Lucas Silva, a rising sophomore at Brockton High School. “So you go back through each line.” When one pair of students called out that their lights were finally blinking in a desired sequence, Barnett observed, “We’re engaging them in problem-solving, coding for a purpose as opposed to learning it ‘just because.'” He added, “We also want them to know science doesn’t always work out.”

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Barnett and his team tested the coding and greenhouse portions of the grant’s program in June at the McDevitt Middle School in Waltham, Massachusetts. Taking advantage of the unstructured two weeks between the start of state-wide standardized testing and graduation, two eighth-grade science classes took an abbreviated version of the coding course and applied those skills to automating the operations of some 90 greenhouses. The miniature structures contained basil, cilantro, or lettuce seedlings, growing in a potting mixture. The short schedule prohibited introducing the transparent soil element into their work, but the goal was similar: employ the coding to automatically maintain a set of predetermined conditions in the greenhouse.

On June 13, Barnett, in shorts, a lavender short-sleeve shirt, and hiking sandals, and sporting a closely cropped goatee, visited the class of McDevitt science teacher Danielle Vincuilla as her students showed off the results of their work to sixth graders and their teachers. Barnett moved easily about the room, squatting down to ask students how the coding had gone and how it controlled their greenhouses. Watching from the back of the room, Rajeev Rupani, senior research associate on the Barnett team said, “It’s great they’re using words like ‘port’ and ‘smartboard’. Two weeks ago, that wasn’t happening.”

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Having spent the first two weeks of the pilot program learning to code and making transparent soil, in the final week the College Bound students brought the three strands of their work together, planting lettuce and cilantro seedlings in transparent soil and installing them in greenhouses they had equipped with code-driven sensors and other devices.

In September, the same group will return to campus on alternate Saturdays to expand on their summer work. They will begin to introduce variables into their greenhouse ecosystems—changing the duration that the lights stay on, say, or injecting pollutants (e.g., a high concentration of salt) into the transparent soil. The conditions in the greenhouses—humidity, temperature, day length—will be continuously fed to a computer dashboard, allowing students to analyze the growth of the roots, which will be photographed at different stages. The information the group generates can be added to the data collected by the Cademartiri lab. The goal, says Barnett, is to “get kids doing real research, the same sort of stuff that is going on at a university.”

Barnett plans a roll out of the transparent soil program in spring 2019 that will involve 16 teachers in Massachusetts, Colorado, and Iowa. “I’m feeling good about this going into classrooms,” he said in late July. As for the students, he said “they were great.” But he adds, “It takes a couple of years for them to really internalize what they’ve learned and feel, ‘I can do this.'”

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