Aid ProjectsCommercial Farm ProjectsFood ShortagesGlobal Warming/Climate ChangeSoil Erosion & Contamination

Sandbar Cropping in Bangladesh

Bangladesh, home for one of the largest deltas in the world, is facing the adverse effects of climate change with riverbank erosion and flood water inundation during the annual monsoon. This has resulted in loss of agriculture crops, livestock and homesteads. The amount of cultivable land is reducing every year in an ever-changing landscape. Sandbar cropping has made a positive impact in converting these unfertile barren sandbars into food producing lands. This has aided in providing climate-resilient livelihoods to the vulnerable farmers by strengthening their food security.

Introduction

Every year millions of people in Bangladesh are effected by flooding and riverbank erosion. With most parts of the country being less than ten meters above sea level, cyclones, storm surges and seasonal floods are common yearly events. Over-population is forcing extremely poor people to inhabit unstable riverbanks and flood-prone areas. Every year more than 100,000 end up becoming environmental refugees and are forced to relocate as their houses and livestock are washed away and their farms are flooded or eroded by rivers.


Ganga-Brahmaputra Delta


Sandbars and charlands in Kazipur Upazila, Bangladesh

Climate change has worsened the situation. The rise in temperature and unpredictable rainfall patterns have resulted in increased river flow, frequent and severe floods, higher river bank erosion, prolonged drought and increased salinity intrusion (3).


Floods inundating farms and houses. Image © Shiree, Practical Action Bangladesh.

As rivers recede, large sand islands called sandbars emerge. Sandbars containing sand and silt, being non conducive for vegetative growth, end up as barren lands. Practical Action, an International NGO, has developed ‘sandbar cropping’ techniques in partnership with local communities to cultivate these silt deposited sandbars to grow vegetables like pumpkin, squash and lettuce (1). In four of the northern districts of Bangladesh, sandbar cropping has helped many landless families to diversify their incomes and overcome seasonal food shortages, thereby helping them to adapt to the changing environment.

Sandbars

Sandbars are large, temporary, barren lands made of the sand and silt deposited as the rivers flood and subside as well as when they change their course.

Sandbars can be categorized into three main types (1, 7):

Type 1: Sandbars covered with sufficient silt. They have sandy loam soil characteristics with capacity to retain moisture for a longer period of time. They are generally located on the banks formed by river erosion and are used to a good extent for growing tobacco, maize, potatoes, chilli, onion, garlic and millet.

Type 2: Sandbars with no silt. They have only sand deposits and are not suitable for crop production. To utilize these sandbars Practical Action Bangladesh came up with sandbar pit cultivation technique.

Type 3: Sandbars emerging in the downstream South are different from those in the upstream North. Sandbars in the South are formed by the accretion process of alluvial deposits. Since they are raised from the river beds, they are more permanent in nature and are less likely to erode. These lands are inhabited and are cultivated. In the North, sandbars are not raised and are basically dried up parts of river beds. They are prone to erosion and are not a stable, dependable land for cultivation.

Sandbar cropping techniques transform these unproductive, unutilized lands into productive, cultivatable, revenue-generating land for very poor landless people.

https://www.youtube.com/watch?v=4HOf1Unv_IU
Sandbar cropping helping to adapt to climate change (Duration 6:34 minutes)

Sandbar Cropping Technique

At the end of rainy season in mid-November, as the water level in the rivers recede, sandbars start to emerge. These sandbars are brought under cultivation using the sandbar cropping technique.


Sketch showing the sandbar cropping technique. Image source (1).

The sandbar cropping technique is a pit cultivation approach, adapted to the sandbars to grow pumpkin, squash and watermelon. Pits are dug in the sandbars and are lined with manure and compost. Jute sacks are used in locations where ground water is very poor. Seeds are placed in the pits and are carefully monitored for the next few months with periodic irrigation and nursing as required. The details of the implemented technique (1, 3, 5, 6) is as follows.

  1. Pits of dimensions one meter in diameter and one meter in depth are dug. Pits are placed approximately two meters apart.
  2. Then, the bottom of the pit is filled with about 10-15 kg of compost/cow dung mixed with pit soil. This is left for 15 days.
  3. Next, 4-6 seeds are planted in each pit and the pits are soaked with water.
  4. Once the seeds germinate, 2-3 healthy seedlings are kept in each pit and the rest are uprooted.
  5. Pits are usually covered with straw mulch to preserve moisture.
  6. Pits are soaked 2-3 times a week with water.
  7. When the seedlings are 25-30 days old, quick compost is applied at a rate of 1kg/pit.
  8. At the same rate, after 60-65 days another round of compost-soil mix is applied, and is followed with irrigation.

Irrigation

Since sandbars are close to the rivers, irrigation is done carrying water in pitchers or buckets. In the initial months of cropping, surface water available in the water channels created by receding rivers are used.

When the surface water dries out, ground water is used with the help of a borehole and pump. A low cost reservoir made with polyethylene sheeting is used for optimized use of water. Water is pumped from the borehole to the reservoir through polyethylene pipes. Using buckets and pitchers, water from the reservoir is taken to individual pits. The quantity and frequency of irrigation is dependent on the type of soil and season (end stage of the production benefited by rain water) (1, 3, 5, 6).


Pits of dimensions one meter in diameter and one meter in depth are made.
Image © Shiree, Practical Action Bangladesh.


Pits are dug 1-2 meters apart. Image © Shiree, Practical Action Bangladesh.


Compost/manure mixed with soil. Image © Shiree, Practical Action Bangladesh.


Plants starting to grow. Image © Shiree, Practical Action Bangladesh.


Water pumped from borehole. Image © Shiree, Practical Action Bangladesh.


Polyethylene water reservoir. Image © Shiree, Practical Action Bangladesh.


Watering the plants. Image © Shiree, Practical Action Bangladesh.


Pumpkin plant in the early stages of growth. Image © Shiree, Practical Action Bangladesh.


Nursing the Squash plants. Image © Shiree, Practical Action Bangladesh.


Pumpkin ready for harvest. Image © Shiree, Practical Action Bangladesh.


Farmer harvesting. Image © Practical Action Bangladesh


Harvested pumpkin ready for sale. Image © Shiree, Practical Action Bangladesh.

After about four months the pumpkins are ready for harvest and are then stored in the farmer’s house on raised platforms made of bamboo. They can be stored for long periods — up to one year. This not only acts as a source of income during lean periods, but also provide food security for the farmer’s family.

Other than pumpkin and squash, farmers also grow vegetables such as lettuce (green and red), strawberry, beetroot, broccoli and watermelon (4). Thus both short term and long term nutrient requirements of the farmer’s family are met.


Other crops grown: lettuce, strawberry, beetroot, broccoli, watermelon. Image source (4)

Positive Outcomes

The introduction of this simple cropping technique has come as a blessing for these extremely poor people. The income generated by selling sandbar crops is enabling these poor farmers to build assets like the purchase of domestic animals — goats, sheep, cows, ducks, hens — and the purchase of boats, rickshaws and bicycles. People are now able to afford medical treatment and repay their loans (3, 4).

One notable change has been the empowerment of women in these remote riverbank regions. In the past, because of extreme poverty and fragmented family conditions, women were the most deprived members of the society, facing adverse conditions in terms of social oppression and economic inequality. Now women are playing an active role in farming and are contributing to family income. Their importance and role in family decision-making has improved significantly and they have been empowered not only in the socio-economic dimension but also in familial and psychological aspects (4).


Asset generation & empowerment of women. Image © Shiree, Practical Action Bangladesh.

Concluding Remarks

Farming techniques like sandbar cropping are the ones which are most needed in this remote and difficult landscape, so the people can adapt to the local environment. It has made a significant impact on the resource-poor and displaced communities of Bangladesh by providing opportunity for food production in barren lands, a decent income, asset generation, increased food consumption, improved nutrition and alternative risk management strategies during lean periods. This climate adaptive agriculture technique is making farmers resilient to climate change and has provided some hope and confidence towards facing the difficult times ahead.

References:

  1. Practicalaction.org
  2. Shiree.org
  3. Climate Adaptive Food Secured Models: Collection of Evidence Base”, Unnayan Onneshan, 2013.
  4. Learning from Phase-1”, PFP-shiree Project, Practical Action Bangladesh, 22 April, 2012.
  5. Green Job Assessment in Agriculture and Forestry sector of Bangladesh”, International Labour Organisation, Bangladesh, April 2009.
  6. Innovative Agricultural Adaptation a Case Study on Sandbar Cropping in Sirajgonj, Bangladesh”, RESOLVE, Unnayan Onneshan, 2012.
  7. Accessing and Retaining Access to the Sandbars by Extreme Poor: Experiences from the Practical Action Project”, Khan Areef Ur Rahaman, Imran Reza, Practical Action Bangladesh, EPR-shiree, March 2012.

Ravindra Krishnamurthy

Ravindra Krishnamurthy is a freelance science writer covering science, tech, the environment, health, food, and culture.

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