Florida sixth grader Naboshree Santra developed biodegradable soilshade balls designed to reduce evaporation and retain moisture; the 11-year-old is now competing for a $25,000 science prize

• Naboshree Santra, a sixth grader at Jackson Heights Middle School, made special soilshade balls that break down naturally.
• These balls slow down water evaporation and help the soil stay wet for longer.