18 Nov The Bunds: Cooling Down the Planet
By Dr Julia Petzl-Berney, UNE Discovery
Have you ever heard of a “Bund”? We found this story fascinating and thought we’d share it with you.
A deceptively simple way of slowing the flow of rain over the soil is regenerating degraded land and bringing both ecological and social benefits to landscapes and communities. A series of large half moons, also known as “earth smiles” or bunds, are dug into the soil in dry times. Native grass seeds and sometimes trees are planted into the bund and when it rains, the water is trapped by the bund and soaks into the soil, rather than rushing over the top and causing erosion. This technique is being applied on a massive scale in Africa, with lasting benefits to the environment and communities.
Recently dug bunds in Tanzania
Credit: CNN World courtesy of Justdiggit.org
Just Dig It is a land restoration charity which aims to restore the soil, the seed bank and the water cycle in degraded landscapes, by digging bunds, using stone lines or farmer managed natural regeneration of trees. According to their website, they have several re-greening projects in Tanzania, Kenya and Senegal. Biologist Trishala Naidu, from the NGO Planet Wild, explained that less reliable rainfall and longer periods of hot, dry weather has led to soils reaching a tipping point, where they are unable to absorb water even where there is rain. Visiting a project in Kenya, Naidu was able to dig a 5 metre-wide bund in about an hour, using simple tools, after which she placed native grass seeds into the hole and protected them with thorny branches. For 65 000 Euro (approx. $105,150 Australian dollars), Just Dig It has created 8000 bunds over 100 hectares and planted millions of grass seeds. The organisation predicts that 2 billion litres of water will be retained over the next 20 years, and that the ecosystem will be fully restored and the livelihood for the local Maasai people who have grazed livestock in that area for thousands of years will be sustainable.
Bunds filled with water after rain
Credit: CNN World courtesy of Justdiggit.org
Another project, run by the United Nations World Food Program (UN WFP), is being implemented in Niger, a country with a nine-month dry season followed by rain. According to permaculture expert Andrew Millison, digging bunds slows the flow of water across the landscape, and the bunds act as mini-reservoirs, allowing plants to grow and flower. The result is a return of biodiversity, lowering of temperature, and reduced soil erosion. Bund projects therefore have an important role in food security, because the increased vegetation cover allows people to graze herds of cattle and goats, according to Millison, who visited the Niger project in 2023. The bunds are dug by local people, who are paid for their work, bringing further economic stimulus into the region.
Even in areas some distance from the restored landscapes, benefits are being felt. Water, which now soaks into the ground instead of running off, replenishes aquifers, meaning that many communities once again have water to irrigate market gardens year round, according to John Mazunda, of the UN WFP). Before the restoration project, nine out of ten children tested in this area of Niger, were malnourished, said Mazunda. Now that communities are able to grow a variety of nutritious fruits and vegetables to sustain them, the rate of malnutrition has decreased, he said.
Bund regreening after four years
Credit: CNN World courtesy of Justdiggit
According to the UN WFP, in 2023 7.9 million people benefited from their programs, including landscape restoration by bund digging, across 47 countries. 376,500 hectares of land were rehabilitated, and 111,800 community gardens were established.
If you’re interested, you can watch Trishala Naidu dig a bund in Kenya here:
https://www.youtube.com/watch?v=vG1H9Sg4lBM
Find out more about the work of the United Nations World Food Program here:
https://www.youtube.com/watch?v=xbBdIG–b58
Or if you like facts and figures, you can do some reading here:
https://docs.wfp.org/api/documents/WFP-0000161194/download/?_ga=2.204856528.1334888900.1732579766-822812938.1732579765
For the work of Just Dig It, including a really cool before and after shot of bund restoration: https://justdiggit.org/