Meran Campbell-Hood's ingenious science project was one of 20 by New Zealand's most talented science pupils which were selected by the Royal Society of New Zealand for the Genesis Energy Realise the Dream competition.
The 15-year-old's research began in year 7 when her grandfather posed the question: Can soil nutrients be detected by photography?
Each year since then, she has developed and improved non-destructive ways to determine if plants have been able to take up some of the more difficult nutrients to analyse in the soil, including copper and, most recently, selenium.
This year, she put her system through a long-term trial with 80 days of observations on patches of a lawn that had received different amounts of sodium selenate.
She developed processing algorithms to filter non-grass pixels from the image and had to cope with day-to-day variations in lighting conditions, including shadows across part of the image.
The judges found her system performed well, and she was awarded the Royal Society of New Zealand Travel Award, which will enable her to take an all-expenses-paid trip to the 2014 Youth ANZAAS Science Conference for secondary school pupils in Melbourne.
''It's great, quite unexpected. I never go into these things expecting to win,'' she said.
Other projects selected included topics of air and water quality, nutrition, memory, sand dune restoration, hypothermia monitors, spider web strength and an automatic gearbox for bicycles.
Chief judge Associate Prof Cory Matthew, of Massey University, said this year's competition drew some outstanding entries which bodes well for New Zealand's scientific future.
He said the projects showed high skill levels in electronics, image analysis, robotics, ecology and physics, among others.
Meran's travel award was one of several awards presented at the Genesis Energy Realise the Dream event held and hosted recently by the Governor-General at Government House.
Given that Meran still has two years of study left at Logan Park High School, she has not made any concrete plans about her future, but hopes eventually to study some form of science at university.
