Emerging waterscapes: When the land is not enough

With more than a thousand people per square kilometre, Bangladesh has by far the greatest population density of any similar sized country in the world. Land is scarce, and the flooding seems to get worse year after year. But, the emerging use of seasonal islands and floating gardens now offers some farming families a new way to grow crops on the waterways that otherwise threaten their very existence.

Farmers think of alternative ways of producing food when land gets flooded often.

Bangladesh is one of poorest countries, and farming families have to make use of whatever space is available. Crisscrossed by 230 of the world’s most unstable rivers, the situation is worsened by flooding that affects millions of people each year. At least 100,000 women, men and children are forced to move as villages and livelihoods are literally washed away. And in recent years, flooding has intensified and lasted longer.

So if there is no more land, why not go to the water? Mohammed Saiful Islam and Tara Begem did, thanks to the support of NGOs, the international Practical Action and national partners, who provided technical and financial assistance. They helped to pioneer two innovative, low cost and local adapted approaches – sandbar cropping and floating gardens. Early successes suggest that they have great potential for use in other parts of the world, and this is good news that needs sharing.

Sandbar cropping

What are sandbars?

Sandbars are large, temporary and barren lands made of sand and silt, deposited as rivers flood and subside or change their course. These islands emerge as flooded rivers recede, not stable enough to support permanent vegetation and remaining only until the next year’s rains wash them away. As such, they are common property resources but were never before utilised. Similarly temporary ‘land’ may also occur along river banks or as charland (where such deposits are found on fertile farmland). In northern Bangladesh, sandbars appear at the beginning of the dry season in November, and disappear as the rainy season starts in April.

This technique was developed through a series of initiatives in Rangpur division, when Practical Action Bangladesh began a trial with 177 farmers in 2005, starting with the objective of ‘something is better than nothing’. This was part of their ‘Disappearing lands’ project which went on to win the Asia-pacific (APFED) gold award in 2007.

This was then expanded in a second project funded by EEP and a joint initiative between the governments of Bangladesh and the UK. This was designed to benefit 32,000 households whose villages and farms had been lost through river erosion in five districts in northwestern Bangladesh covering 9000 km2 and who had been forced to live on flood protection embankments.

At the age of three, Mohammed Saiful Islam and his family were forced to move when flooding destroyed the family home. They had to move another four times in the next ten years, before settling on a flood protection embankment in Haripur in 1992. He continues to live there, now with his wife and two children. After separating from his parents at marriage, he became a day labourer enduring low wages, forced migration to other districts. He had to sell his labour in advance in the lean season, meaning that the family suffered from a lack of food most of the time. In 2006, he became one of the first farmers to receive training, seeds and compost by AKOTA. AKOTA is one of the five local NGOs promoting sandbar techniques with 3200 families in the region. He began by preparing 50 planting pits, but was very uncertain as to what to expect.

Pumpkins from sand pits

“The opportunity and the technology is a blessing for us, it has opened our eyes to see a better life and a new hope to live.”

The season for pumpkin cultivation starts at the end of the rains, the time when the rivers recede and sandbars appear. Saiful was shown a suitable site and working with technicians, they developed a system of preparing planting pits. These were one metre deep and one metre wide, and around two meters from each other.

Pits were then lined with a mixture of cow dung, soil and water. Jute sacks are also used to line the pits in extreme locations. Allowed to settle for a few days, seeds were then sown. Being close to the river, the pits are easily watered by hand in the early months. At the end of the dry season when plants need extra water as the fruit expands, boreholes were dug and pumps and temporary plasticlined reservoirs helped by providing water for irrigation.

Saiful was astonished with the amazing harvest of pumpkins and the profit he made that first year from only 50 pits. The following season, he and his family prepared 433 pits from which they earned a small fortune. He harvested 2809 pumpkins with an average weight of 7 kg and many more sweet gourds. He has since become a model in the community, thanks to his success with sandbar cropping, and has invested the profits in aquaculture and beef fattening. Saiful said “The opportunity and the technology is a blessing for us, it has opened our eyes to see a better life and a new hope to live.” He and his brother now plan to expand production in the following years to more remote sandbars and to try different crops.

The experience of Practical Action, national partners and the farmers, suggests that as few as one hundred pits can bring tangible and significant improvements for an extremely poor farming family. It is a simple and low cost technique that requires no special inputs. The pumpkins produced on the sandbars can be stored in people’s home for more than a year and therefore greatly assist poor households with income generation, food security and lean season management. In the winter dry season, sandbar cropping also transforms the barren landscape of these ‘mini desert islands’ into productive green fields which also support a wide range of insect, birds and other small animal species due to the habitat created.

With additional support, the technique and the benefits have been greatly outscaled in northern Bangladesh. More than 160,000 family members are thought to be benefitting, and the idea is spreading. Sandbar cropping techniques have been taken up by Care Bangladesh, Concern Worldwide, Friendship International, interest shown by UNDP and field visits by the Ethiopian Ministry of Agriculture.

Practical Action trained staff from 13 NGOs from 10 districts, with additional farmer to farmer training at a local level. At the national level, this technology has been promoted by significant media coverage through television and radio broadcasts.

Since 2005, more than 15,000 people and their families, mostly displaced or landless and mostly women, have adopted the sandbar cropping technique and produced more than 55,000 tonnes of pumpkins worth more than five million US dollars. These experiences clearly show how innovation can help family farmers, when their land and livelihood is put under pressure by ever more mouths to feed from the same land, and further threatened by more natural disasters in form of floods. The answer here is, to make the best use of any land, however temporary, and also any river or lake if local materials are available to make new land on water.

Floating gardens

Tara Begum and her family are not affected by monga (famine) any more. Once destitute, they have changed their lives with floating vegetable gardens on the Brahmaputra river in Bangladesh. Tara lives with her husband and son in a small compound in Shingria, 15 km from Gaibandha town. Her family has been displaced by flooding seven times and now lives on a government flood embankment, with 0.2 acres (800 m2) of sandy and infertile land covered with water during the monsoon. But now, she say, “My floating garden has made a great difference to my life. Now I have enough food in the floods and I can give some to help my relatives as well.” More than 1200 farmers using floating gardens have already produced more than 250 tonnes of vegetables with an equivalent market value of US$40,000.


This aquatic plant has spread around the world and is often seen a nuisance or invasive weed. However, azolla grows very quickly, is rich in nutrients and can be used as a fertilizer and as an animal feed. Efforts are being made to further develop this plant as a resource for smallholder farmers.

Water hyacinth

Originally from South America, it has been described as one of the world’s worst invasive plants, and is proving to be a huge problem especially in Africa. However, in parts of Asia it is cultivated as an animal feed and its uses are being increasing promoted as a ‘free’ resource. Making floating gardens is another use to add to the list.

The Bangladeshi method involves collecting a mass of water hyancinth, a floating but very invasive weed, overlaid with bamboo poles of the desired length. More water hyacinth is added until a buoyant raft is formed. At this point, the bamboo can be removed and reused. The final growing medium is then added on top, a 25 cm deep layer of mixed soil, cow manure, azolla, and any other available organic matter.

Well maintained and with regular additions of new mixed substrate, rafts can last for years. They can be anchored in sunnier or shadier sites depending on the crops being grown, and in Bangladesh these are usually okra, aubergine, pumpkin, onion and various leafy vegetables.

When the rafts finally begin to decay, they are broken up and can be used to prepare a new garden for the next season. Rats, ducks and other animals are attracted to the islands and can become major pests if not protected by fencing with sticks and old fishing nets.

Floating gardens or reclaimed land?

Reclaimed land for agriculture were common landscape features in parts of Central America from at least a thousand years ago, with such areas often described as ‘floating gardens’. In reality however, these chinampas were more like raised beds or artificially created islands. They provided ample food for the Aztec capital of Tenochtitlan, which when the Spanish arrived in 1519 was five times the size of London and may have been the biggest city in the world at that time. The Mexican system involved the staking out of an area of shallow lake bed with stakes and filling up with mud, vegetation and sediment from the lake bed until dry land appeared, often with the planting of trees to help stabilise the edges. The sediment proved to be very rich in plant nutrients and was added every year as a fertilizer while also replacing the substrate that tended to be washed away. Polders are much the same as chinampas but at a much larger scale, and reclaimed from the sea as well as inland water bodies. Whereas small man made islands date back to the Pharoahs, the oldest polders are Dutch and also about a thousand years old. However, there are also polders in at least 15 other countries, including Bangladesh, India and Guyana.

Nazmul Choudhury and Nirmal Bepary

Practical Action
House 12/B, Road 4, Dhanmondi Dhaka- 1205,Bangladesh.
Email: nazmul@practicalaction.org.bd / nirmal.chandra@practicalaction.org.bd

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