Kiara whipped up three recipes containing orange peel: a liquid, a powder, and a mixture that also included avocado skin and lemon juice. She did three experiments to determine the best one. First, she tested which material absorbed the most water. Then she blended each into a pot of soil and measured how much the soil dried out over time. Finally, she grew plants in soil with each material. She watered each plant a tiny amount, then monitored its health.
The tests had a clear winner: the mixture of orange peel, avocado skin, and lemon juice. Soil with this material in it held on to the most water. The plant lived without being watered for three weeks.
Kiara entered her project in the international Google Science Fair, where it won the grand prize last year. She hopes to make more of the mixture and give it to farmers to use on crops during droughts.
Kiara encourages other kids to tackle big problems. “Even if you’re young, you still have the ability to create something world-changing,” she says.