Relay cropping answer to coastal farming

The coastal region of Bangladesh makes up about one-third of the country's total land area, of which approximately 439,000 hectares (almost 1.1 million acres) remains fallow during the dry season due to increased salinity and inadequate irrigation facilities. Aman rice is the only crop cultivated there during the monsoon season. After the Aman rice harvest in December, these vast tracts of land, particularly coastal regions remain fallow for 6-7 months. To bring this extensive barren land area under cultivation, Independence Award-winning agricultural researcher Dr. M. G. Neogi, in collaboration with the Australian Center for International Agricultural Research (ACIAR), has developed a unique relay wheat cropping model that deserves policymakers' attention for wider adoption.
In conversation with this scribe, Dr. Neogi said, "It is possible to turn the single-crop land in coastal areas into double-crop or even possibly triple-crop land by using relay wheat cropping method." Dr. Neogi and his team have been working on the relay wheat cropping model in Bangladesh's coastal regions since 2017.
Relay cropping involves planting a second new crop in same land while the first crop is still in the field with its mature stage. As wheat and pulses can be grown with minimal irrigation and wheat exhibits some degree of salinity tolerance, the researchers figured out that wheat could be the ideal for relay cropping in these vast areas of fallow land. But here lies a problem.
Typically, cooler temperature, below 15°C, is ideal for wheat cultivation. Such an ideal cool weather condition for wheat crop production is available in coastal Bangladesh only during the later half of December and January. Therefore, the optimal sowing time for wheat in coastal Bangladesh is mid-November. But coastal lands remain covered by Aman paddy in November, which farmers harvest in December. To overcome this challenge, Dr. Neogi suggests sowing wheat seeds directly into the Aman paddy fields during mid-November, when paddy plants are in their matured stage. This is called relay wheat cropping model.
This method enables wheat cultivation without disturbing the standing rice crop. Moreover, this allows the wheat crop to grow during the favourable cool weather conditions of January.
Regarding potential damage to wheat seedlings during rice harvesting, Dr. Neogi said, "Farmers can harvest rice using traditional sickles without harming the wheat seedlings growing within the rice field. Typically, coastal farmers harvest rice by cutting the stalks approximately six to seven inches above the ground level, which would ensure the safety of the emerging wheat seedlings." Moreover, as he said, "Research has shown that even mechanical harvesters can be used without causing significant damage to the wheat seedlings. Observations have shown that wheat seedlings can recover quickly within two to three days after the rice harvest is completed."
Numerous farmers in Barguna and Patuakhali have successfully implemented this method, and they are pleased to have an additional profitable cash crop with minimal production costs. Relay technology significantly reduces expenses by eliminating the need for ploughing. Furthermore, wheat cultivation requires considerably less water for irrigation. With the relay cropping method, farmers can minimise water usage to just three to four light irrigations. Additionally, unseasonal rainfall between November and February, driven by climate change, further decreases irrigation needs.
Dr. Neogi's research has shown that in relay wheat planting, the cost per bigha is approximately Tk. 5,000, (Tk. 37,500/ha) yielding about 400 kg (3 t/ha) of wheat. At a market price of Tk. 40 per kg, the total income is Tk. 16,000/bigha (Tk. 120,000/ha). If relay wheat cultivation is expanded to the 439,000 hectares of fallow land of the coastal region in dry season, it could potentially yield 1.3 million tonnes of wheat, which could go a long way in fulfilling the country's growing demand for wheat.
Currently, Bangladesh requires 7.5 million tonnes of wheat annually but produces only 1.1 to 1.2 million tonnes domestically. This shortfall of 6 to 6.5 million tonnes is met through imports, resulting in a significant outflow of foreign currency. Against this backdrop, Dr. Neogi's research and practical field studies have shown that wider adaptation of relay wheat cropping can open up a vast horizon to explore the potential for cultivating wheat in coastal saline lands.
Moreover, relay wheat cropping can help mitigate rising soil salinity. The extended periods of unused coastal land contribute to increased soil salinity due to capillary action, where salt moves from deeper soil layers to the surface. Since relay cropping minimises soil exposure and reduces capillary action, it could mitigating salinity buildup. On March 6, 2024, a field study conducted by the Soil Science Department of Agricultural University, Gazipur demonstrated this effect. Soil salinity levels in a relay wheat plot were found to be significantly lower (5.48 decisiemens per metre) compared to adjacent fallow land (9.63 dS/m), indicating that relay cropping not only enhances crop yields but also improves soil quality by reducing salinity.
The reduced salinity levels resulting from relay wheat cultivation can open up the possibility of cultivating a third crop - Boro rice - after the wheat harvest. Farmers are currently exploring the cultivation of short-duration late Boro rice varieties, such as Binadhan-14, following the relay wheat harvest. Thus the successful implementation of relay wheat cropping can transform vast stretches of coastal single-crop land into a triple-crop one. This will not only benefit coastal farmers but also contribute significantly to the country's food security.
Regarding irrigation management, Dr. Neogi said, "Salinity is a significant challenge for crop cultivation during the dry season in the coastal fallow lands, along with insufficient irrigation water. Studies have shown that the water table just below the surface of these saline lands is also saline and unsuitable for irrigation. However, deeper groundwater sources, typically found at depths exceeding 1,000 feet, are generally salinity-free and suitable for both irrigation and consumption."
Submersible pumps can be used to lift water from these deeper depths. The cost of acquiring and installing a complete pump system, including the borehole and necessary fittings, is approximately 1.5 lakh taka. However, a single pump can effectively irrigate 50 bighas of land, enabling the cultivation of wheat and other Rabi crops using relay cropping techniques. Moreover, the wells will also provide access to safe drinking water for the local community throughout the year.
It is, therefore, hoped that policymakers would consider the issue and actively support the wider adoption of this cropping method by providing necessary resources, training, and incentives to farmers.

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