How a Girl Outsmarted Saltwater to Save Crops

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25th April, 2019

Le Thi Hong Gam, a teenager living in the Mekong Delta in Vietnam, saw how saltwater was destroying crops in her village. Determined to do something about it, she applied what she learned from her physics class. Gam’s simple yet ingenious idea made a major impact in her community, and gave farmers hope.

Addressing a Serious Agricultural Problem in the Mekong Delta

The Mekong Delta is a maze of rivers and islands in the southern part of Vietnam. With its long coastline at low elevation, in recent years the delta has been vulnerable to seawater intrusion due to climate change. During the dry season when rainfall is low, saltwater creeps into the delta, and the increased salinity has had a destructive effect on crops.
Since Gam’s family grows vegetables to make a living in the delta’s Vi Thanh City, they experienced first-hand how saltwater was destroying crops in their community. Gam’s father, Le Van Tam, explained, "The issue in this area is that when saltwater intrusion occurs, the farmers are not aware of it. They don’t know when it has happened. We spray saltwater on our vegetables, then everything dies."

Floating Small Rubber Balls to Make a Big Difference

A resourceful and creative student who wanted to do something about the saltwater problem, Gam came up with the idea for "Saltwater Balls" after getting some help from her teacher and friends. The concept is based on Archimedes’ Principle. By observing how saltwater affects buoyancy, Gam and her friends developed a simple way of detecting salinity by using colorful balls filled with different percentages of saltwater. Depending on the level of salinity, one ball or another would float.
When they put their idea to the test under a dock, they could see that if a corresponding ball was floating, the water was too salty for watering crops. If the balls sink when the tide goes down, the water can be considered safe for watering crops. With this affordable method of detecting salinity, many crops have been saved. Gam is now donating Saltwater Balls to farmers to help them. She said, "Our reward was that we were able to make a difference."

Using Our Technologies to Keep Water Safe and Pure

Like Gam, we at Mitsubishi Electric also want to contribute to society by supplying water that is safe to use and drink. We have an extensive track record of providing equipment for water treatment plants and water purification facilities. One solution we offer is our ozone generator, which utilizes ozone to sterilize and deodorize water without using chlorine. We also provide a microbubble cleaning technology that cleans oily pipes without using any detergents. And we developed a new water treatment technology based on a gas-liquid interface electrical discharge. Our efforts to treat water and safeguard the environment were recognized by CDP, a global disclosure system that encourages companies and cities to manage their environmental impacts. In 2018, the organization gave us the highest rank in two categories, climate and water, for the third consecutive year.
Just as Gam is helping farmers yield more crops with fresh water, we are also contributing to society by helping to keep our most precious resource safe and pure.

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