Photo credit: Scientific American
Gardening on towers and sacks. Photo: Amy Yee
Vertical Gardens Beat Soil Made Salty by Climate Change
Saltwater is shrinking Bangladesh’s arable land, but a simple approach of planting crops in containers shows surprising success
By Amy Yee
The soil in Chandipur village in southwest Bangladesh has become increasingly salty because of incursions of seawater. The situation became particularly acute in the aftermath of Cyclone Aila in 2009, which brought storm surges that broke embankments and flooded farmland. After 2009 vegetable crops planted in the ground there yielded only meager returns—if they didn’t fail completely.
But for the past three years hundreds of villagers have enjoyed the bounty of so-called vertical gardens—essentially crops grown in a variety of containers in backyards and on the rooftops of their humble homes. Despite their modest size, these gardens produce quite a bit.
Working with local nonprofits WorldFish trained about 200 villagers in four districts in saline-affected areas of southwestern Bangladesh to make vertical gardens. Others not in the program have copied their neighbors’ designs after seeing how well they worked. WorldFish plans to expand the program to include 5,000 people over the next two years.
Growing the vertical gardens is a relatively straightforward process. Villagers harvest soil after the rains, around November, and use it later during planting season. They put the soil into containers and mix it with fertilizer made of dried water hyacinth, soil, coconut husks and cow manure. The containers range from plastic rice and concrete sacks to large, specially constructed “towers” made of simple plastic sheets encased by bamboo rings.
To prevent waterlogging, the containers are raised off the ground on bricks and filled with brick chips that improve water circulation and drainage. Small holes are cut into the sides where short-rooted vegetables such as Indian spinach and tomatoes can grow. Long-rooted vegetables such as gourds grow on top. These sacks can produce up to eight kilograms of vegetables in one season with an investment of 100 to 150 taka (about $1.30 to $2) per bag. The tower variety of container measures more than 1.2 meters across and can produce more than 100 kilograms of vegetables. One tower requires an investment of about 900 to 1,000 taka (around $11.50 to $13.00) to buy materials and seeds. WorldFish provides seeds and some materials to villagers in the first year.
Read the full article: Scientific American