Teen develops water-saving pods for seeds
WASHINGTON, D.C. — Times are dry in California, which is finishing its fifth consecutive year of drought. Cynthia Chen, 14, began to wonder what she could do to help. After doing a little background research, she found out that 80 percent of the water people use in California goes to farming. So Cynthia — now in ninth grade at the Harker School in San Jose, Calif. — decided to attack the problem by building a water-saving seed pod that keeps seeds moist until they sprout.
Her pod and project won her a second place prize in science at the Broadcom MASTERS. MASTERS stands for Math, Applied Science, Technology and Engineering for Rising Stars. This yearly competition — created by Society for Science & the Public and sponsored by the Broadcom Foundation — brings 30 students from around the United States together to show off their award-winning middle-school science fair projects. (Society for Science & the Public also publishes Science News for Students and this blog.)
Cynthia explored potential ways to reduce the amount of water used to grow the fruits and vegetables we eat. She eventually decided to focus on germination. This is the stage of growth in which a seed sprouts into a young plant called a seedling. It’s also a stage that often requires a lot of water — and where, Cynthia notes, a lot of water gets wasted.
“Usually farmers take seeds and they spray them over the land and cover them with soil and then spray water over,” she explains. “The problem with that is that in between the seeds there’s a lot of soil. The water lays on the soil and is unable to reach the seeds. It evaporates, and thus the water is wasted.”
The teen looked for a way to reduce that water waste and designed a pod for a seed. Each seed sits in a bed of soil inside a small cup. The seed and cup then sit inside a larger cup — the used filter from the inside of a single-serving coffee pod. In between the inner cup and the outer cup, Cynthia placed a layer of water crystals — small granules that absorb water and release it over time — to keep the seed inside moist. The whole capsule can break down slowly into the soil over two to three weeks.
To find out if her pod helped seeds to grow with less water, Cynthia purchased kidney bean, corn and squash seeds online. She started with 24 seeds of each type and divided them into three groups of eight. The first group received 5 milliliters (about 0.2 fluid ounces) of water every two days. The second received 10 mL (0.33 fl. oz.) of water per day and the third received 15 mL (0.5 fl. oz.) of water per day. Half the seeds were placed in her homemade pods and the other half in cups of only soil.
Cynthia gave her seeds a few weeks to germinate and grow. Each day, she checked to see how many had gone from seed to sprout. She also counted how many failed to sprout.
She found that her capsule allowed seeds to sprout faster than seeds in only soil. Beans sprouted 1.7 days faster, corn 0.9 day faster and squash 1.4 days faster. “Those one to two days make a huge difference in farming because each day millions and millions of gallons of water are wasted,” Cynthia notes.
Her capsules also saved water. Cynthia found that seeds in pods that got only 5 mL of water grew just as fast as seeds in soil that received 15 mL of water. Her pods helped more seeds germinate, as well. Eighty percent of the seeds in soil alone sprouted compared with 94 percent of seeds in pods.
But germination is only one stage of plant growth. Cynthia says she’d like to see how her pods affect the beans, corn and squash as they grow. But if it works, she would like to continue to use capsules made of used coffee pods. “If we could apply them to agriculture, it could save waste and save water,” she says. “A double benefit!”
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agriculture The growth of plants, animals or fungi for human needs, including food, fuel, chemicals and medicine.
blog Short for web log, these Internet posts can take the form of news reports, topical discussions, opinionated rants, diaries or photo galleries.
Broadcom MASTERS Created and run by the Society for Science & the Public, Broadcom MASTERS (Math, Applied Science, Technology and Engineering Rising Stars) is the premier middle school science and engineering fair competition. Broadcom MASTERS International gives select middle school students from around the world a unique opportunity to attend the Intel International Science & Engineering Fair.
chemical A substance formed from two or more atoms that unite (become bonded together) in a fixed proportion and structure. For example, water is a chemical made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H2O. Chemical can also be an adjective that describes properties of materials that are the result of various reactions between different compounds.
drought An extended period of abnormally low rainfall; a shortage of water resulting from this.
engineering The field of research that uses math and science to solve practical problems.
evaporate To turn from liquid into vapor.
fruit A seed-containing reproductive organ in a plant.
germinate To sprout and grow.
middle school A designation for grades six through eight in the U.S. educational system. It comes immediately prior to high school. Some school systems break their age groups slightly different, including sixth grade as part of elementary school and then referring to grades seven and eight as “junior” high school.
online A term that refers to things that can be found or done on the Internet.
seedling The initial plant that sprouts leaves and roots after emerging from a seed.
Society for Science & the Public (or SSP ) A nonprofit organization created in 1921 and based in Washington, D.C. Since its founding, SSP has been not only promoting public engagement in scientific research but also the public understanding of science. It created and continues to run three renowned science competitions: The Regeneron Science Talent Search (begun in 1942), the Intel International Science and Engineering Fair (initially launched in 1950) and Broadcom MASTERS (created in 2010). SSP also publishes award-winning journalism: in Science News (launched in 1922) and Science News for Students (created in 2003). Those magazines also host a series of blogs (including Eureka! Lab).
technology The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.
waste Any materials that are left over from biological or other systems that have no value, so they can be disposed of as trash or recycled for some new use.