GAU Soybean 6: drought-tolerant soybean released for Bangladesh's coastal chars

Gazipur Agricultural University (GAU), the former Bangabandhu Sheikh Mujibur Rahman Agricultural University at Salna in Gazipur, announced in late February 2026 that its researchers had developed "GAU Soybean 6", which the university described as the country's first highly drought-tolerant inbred soybean variety. The work was led by agronomist Professor Dr M A Mannan of the university's Department of Agronomy and grew out of about a decade of his research. University officials said the variety brought the number of crop varieties developed by GAU to 94. The news agency UNB and The Financial Express carried the announcement on 26 February 2026, and Jagonews24 published a detailed report from Gazipur on 1 March 2026, setting out how the variety was selected, how it was tested in the coastal districts and what its developers said it could do on dry land and on the chars, the river and estuary islands of the Meghna.

According to Jagonews24, the breeding work began with about 250 soybean germplasm lines gathered from three sources: the Asian Vegetable Research and Development Center in Taiwan, the Bangladesh Agricultural Research Institute (BARI) and South Korea. The researchers tested these lines rigorously for three years, and one line, G00056, was selected for its tolerance of drought. That line then went through five years of field evaluation in Noakhali, Lakshmipur and Bhola, three coastal districts on the Meghna estuary, with support from Solidaridad Network Asia. On the strength of those trials, the National Seed Board gave the variety its formal approval on 11 November 2025.

The Financial Express confirmed the approval date when it published a picture of a GAU Soybean-6 field on 26 February 2026, noting that the variety had been approved by the National Seed Board on 11 November 2025. Jagonews24 and The Financial Express both describe the variety as an inbred one; UNB's English report of the same announcement called it a hybrid, but the university's account as carried in the Bengali report and the Financial Express caption uses "inbred".

The line that became the new variety had already appeared in the Department of Agronomy's own research record. The department's page on its research achievements says its members collected and evaluated more than 1,000 genotypes of rice, mungbean, chickpea, soybean, bush bean, pigeonpea, sorghum, lentil, cotton and cowpea against flooding, drought and salinity, and lists the soybean genotype G00056 among the lines found tolerant of drought stress, together with BU Chola-1 (chickpea), the bush bean BB 024, BU Soybean-2 and BU Mug-2. In the same list of the department's released varieties, GAU Soybean 6 is entered as a high-yielding, large-grained and drought-tolerant soybean.

Professor Mannan told Jagonews24 that the variety has a rare ability to survive and give high yields even in severe drought, when the soil holds only 50 to 60 per cent of field capacity. He said it was being regarded as an exceptional addition for the future of farming, because it could overcome the limits that soybean cultivation faces on the coastal chars.

The yield traits he described were as follows. Each plant bears 80 to 100 pods. Because the seeds are large, 1,000 seeds weigh about 230 grams. Because the variety can out-yield ordinary varieties, it gives 3.2 to 3.8 tonnes per hectare without difficulty. It also matures comparatively early: the crop is ready in three months to three months and ten days, which, he said, lets farmers earn more from a high yield in a short time.

Another feature he stressed was the low level of trypsin in the seed. According to Professor Mannan, the low trypsin content raises the rate at which protein is absorbed when the beans are used in poultry feed, which makes the variety valuable to the poultry industry. He described soybean in general as a strong store of nutrition, containing about 40 to 45 per cent high-quality protein and 18 to 20 per cent oil and rich in essential amino acids, vitamins and minerals.

Summing up, Professor Mannan said: "GAU Soybean 6 is the combined harvest of our long, tireless research, the sun and rain of the fields and the dreams of farmers. Against the hard reality of salinity, lack of rain and uncertain weather on the coastal chars, this variety is quite effective in meeting the challenge. Growing soybean on drought-prone land has so far been largely risky. This variety will break that uncertainty and open the door to new possibilities."

Field capacity is a standard measure of soil moisture. The Food and Agriculture Organization of the United Nations (FAO), in its irrigation water management training manual, explains it this way: after heavy rain or irrigation, water in the larger soil pores drains downward and is replaced by air; when that drainage stops, the large pores hold both air and water while the smaller pores are still full of water, and the soil is then said to be at field capacity. At that point, the FAO manual says, the water and air contents of the soil are considered ideal for crop growth.

As plants take up water and the topsoil dries, the soil moves toward the permanent wilting point, at which the water left is held so tightly that roots can no longer draw it. The FAO manual defines the water available to a plant as the water held at field capacity minus the water that remains at the permanent wilting point, and notes that this available water depends greatly on soil texture: about 25 to 100 millimetres per metre of soil depth in sand, 100 to 175 in loam and 175 to 250 in clay. A soybean crop that keeps yielding when the soil holds only 50 to 60 per cent of its field-capacity moisture is therefore one that copes with a soil already well short of its ideal water content.

Banglapedia, the national encyclopedia published by the Asiatic Society of Bangladesh, defines drought in the Bangladesh context as the period when the moisture content of the soil is less than the amount required for satisfactory crop growth during the normal growing season. It notes that droughts are common in the north-western districts, particularly the Barind Tract, but that drought can also occur in areas that usually enjoy adequate rainfall. Depending on its intensity, the encyclopedia says, the estimated yield reduction of different crops varies from 10 to 70 per cent, and the loss may be considerably reduced through judicious and limited irrigation at the critical stages of crop growth.

Trypsin is a digestive enzyme, and raw soybean contains proteins that block it. A peer-reviewed study by Krisztina Takács and colleagues, published in the Journal of Food Science and Technology in June 2022, explains that the major protease inhibitors in soybean belong to the Kunitz (KTI) and Bowman-Birk (BBI) families. These anti-nutritive compounds inhibit the digestion and absorption of dietary protein, the authors write, and reduce the growth performance of animals; KTI and BBI have also been found to cause enlargement of the pancreas and over-secretion of digestive enzymes in rodents and birds.

The same paper notes that the thermal treatments most commonly used to inactivate these factors, such as hot-air drying and roasting, usually need long exposure, 10 to 20 minutes at 100 to 200 degrees Celsius, because trypsin inhibitors are highly heat-stable, and that prolonged heating has drawbacks of its own. The authors write that the cost of heat treatment can be saved, and sustainability improved, by using soybean varieties with reduced Kunitz inhibitor. That is the background to Professor Mannan's point that a low-trypsin bean is better suited to poultry feed.

Feed is where most of Bangladesh's own soybean goes. Reporting on the US Department of Agriculture's Oilseeds and Products Annual report on Bangladesh, The Daily Star wrote on 26 March 2025 that soybean meal was one of the key ingredients of the poultry and aqua feed industry and that poultry farms consumed about 70 per cent of total feed. The USDA report, as the paper summarised it, said domestically produced soybeans were primarily used in the feed industry and, because of their quality and lower oil content, were not used for oil production; locally produced soybeans met just 7 per cent of the country's demand for soymeal and edible oil. Bangladesh imported 22 lakh tonnes of soybeans in the 2024-25 marketing year, half of it from the United States and a third from Brazil, and the USDA expected soybean meal use in the feed industry to reach 29 lakh tonnes in 2025-26 as the poultry, aquaculture and dairy sectors expanded.

Soybean, Glycine max, is a bushy plant of the legume family that probably originated in China, Banglapedia notes; its young seeds are eaten as a vegetable in eastern Asia and its mature seeds are made into soy milk, curd and sauce. The encyclopedia records that soybean cultivation in Bangladesh started in 1978, mainly in Noakhali and Feni. Over the following decades the crop settled on the coast. An Australian Centre for International Agricultural Research (ACIAR) project note of August 2020 described the Noakhali and Lakshmipur districts as the country's main soybean-growing area, with 75,000 hectares of soybean grown each year.

Lakshmipur is the centre of it. Prothom Alo reported from the district in March 2025 that agriculture officials said 80 per cent of the soybean produced in Bangladesh came from Lakshmipur, which had become known as a "soyaland", and that soybean had been grown in many parts of the district for about two decades. The Department of Agricultural Extension (DAE) in Lakshmipur had set a target of 42,000 hectares for that season, and farmers had sown 1,660 hectares more than the target; officials expected at least 84,000 tonnes of soybean if all went well. Kamalnagar, Ramgati, Raipur and Lakshmipur Sadar upazilas grow the most, including chars of the Meghna such as Char Induria, Char Jalia, Char Ghasia, Char Kachia and Kanibaga in Raipur.

The same report described the season. Farmers sow soybean on land that used to lie fallow after the Aman rice harvest; December to January is the right time to sow, and the harvest comes around May. DAE officials told the paper that the loamy soil of the area suits the crop, that soybean, as a legume, needs little fertiliser, and that the crop is harvested within 130 days of germination. Haidarganj bazaar in Raipur had 45 to 50 wholesale soybean warehouses, and a trader there told Prothom Alo that 70 per cent of the soybean grown in the country was traded in that market.

The USDA report summarised by The Daily Star in March 2025 gives the national picture. It estimated Bangladesh's soybean production at 1.45 lakh tonnes for the 2023-24 marketing year and projected 1.55 lakh tonnes for 2024-25 and 1.60 lakh tonnes for 2025-26, with acreage growing steadily in the coastal districts because of favourable weather, better market access and higher profitability. Farmers typically do not need to irrigate soybean, the report said, because it is sown after the Aman harvest on residual soil moisture. The ACIAR note added that manual sowing delays planting, which raises the risk of damage from the early monsoon rain that is frequent in southern Bangladesh.

A char, Banglapedia explains, is land that rises from the water of a river or estuary: sand bars that emerge as islands within a channel (island chars) or as land attached to the riverbank (attached chars). Once vegetated, such land is commonly called char in Bangladesh, and it often opens new opportunities for settlement and farming. The encyclopedia divides the country's chars into five sub-areas: the Jamuna, the Ganges, the Padma, the Upper Meghna and the Lower Meghna, where the soybean districts of this story lie.

Banglapedia also sets out why chars are difficult farmland. Island and attached chars appear to be less productive than the adjacent mainland, mainly because of less favourable soil conditions in some chars and the uncertainty caused by erosion and frequent floods. Although river water and groundwater are abundant, irrigated crops are scarce in many chars, except those within the Upper Meghna; the chars are extremely vulnerable to erosion and flooding, and early floods can damage crops in the field. These are the conditions Professor Mannan referred to when he spoke of salinity, lack of rain and uncertain weather on the coastal chars.

The three districts where GAU Soybean 6 was evaluated all lie on this coast. Lakshmipur, 1,440.39 square kilometres in Chittagong division, has the Meghna on its west, and Banglapedia lists agriculture as its main source of income, at 47.51 per cent. Noakhali, 3,685.87 square kilometres, is bounded by the Meghna estuary and the Bay of Bengal on the south. Bhola, 3,403.48 square kilometres in Barisal division, is bounded by the Bay of Bengal on the south, by the Meghna and the Shahbazpur channel on the east and by the Tentulia river on the west.

GAU's roots go back to 1980. Banglapedia records that the government set up the Bangladesh College of Agricultural Sciences in 1980, transformed it in 1983 into the Institute of Postgraduate Studies in Agriculture (IPSA), which received technical cooperation from Japan's JICA from 1985 and from USAID from 1986, and in November 1998 established the university by redesignating IPSA under Presidential Order No. 16 of 1998, as Bangabandhu Sheikh Mujibur Rahman Agricultural University, on its campus at Salna in Gazipur. According to the university, it has been named Gazipur Agricultural University since 12 February 2025, under Ordinance No. 5 of 2025.

Jagonews24 reported that Professor Mannan's research team had already produced five other high-yielding soybean varieties, including ones with salt and waterlogging tolerance. The Department of Agronomy's list of released varieties describes them. BU Soybean 1 matures at least 15 days earlier than other varieties, depending on region and sowing time, runs less risk of drought damage during grain filling, stands 35 to 42 centimetres tall, needs less water and fertiliser than conventional varieties and can be intercropped with sugarcane, maize, sunflower, banana or papaya. BU Soybean 2 suffers much less from waterlogging and cyclone wind in the south, takes 100 days in the Rabi season and 90 in the Kharif season, has white flowers and oval seeds weighing 220 grams per 1,000, and yields 3.5 tonnes per hectare on average.

BU Soybean 3 and BU Soybean 4 are listed as saline-tolerant, high-yielding (3.0 to 3.8 tonnes per hectare) and large-grained, maturing in 80 to 85 and 85 to 90 days respectively in the Kharif-II season and 90 to 95 and 95 to 100 days in the Rabi season. BU Soybean 5 is listed as waterlogging-tolerant, yielding 3.5 tonnes per hectare in 75 to 85 days depending on the season. GAU Soybean 6 adds drought to the stresses the series is bred for.

The university's Vice-Chancellor, Professor Dr G K M Mostafizur Rahman, expressed satisfaction at the result. "GAU Soybean 6 is a landmark achievement in Bangladesh's agriculture," he said. "It can become a symbol of sustainable agriculture in strengthening the country's food security and bringing stability to farmers' lives." He thanked the research team and the laboratory and field scientists.

The germplasm came partly from the Asian Vegetable Research and Development Center (AVRDC), founded in 1971 with its headquarters at Shanhua in Tainan, Taiwan, and rebranded as the World Vegetable Center in 2008; the centre aims to reduce malnutrition and alleviate poverty in developing nations by improving vegetable production and consumption. Another part came from BARI, which Banglapedia describes as the autonomous institute under the Ministry of Agriculture responsible for research on all crops except rice, jute, sugarcane and tea; its central station is at Joydebpur in Gazipur, and it runs crop-based research centres including an Oil Crops Research Centre and a Pulse Research Centre.

Solidaridad Network Asia, which supported the field trials, is an international non-governmental organisation that, according to the ACIAR note, began promoting soybean in south-eastern Bangladesh at the beginning of 2018, working with 26,000 farmers through 15 lead farmers and five producer companies and providing technical support and market links. With Murdoch University and the manufacturer Hoque Corporation it piloted a two-wheel-tractor-driven Versatile Multi-crop Planter for soybean in Noakhali and Lakshmipur; farmers who used it reported a cost saving of A$165 per hectare and a grain yield about 600 kilograms per hectare higher. In May 2025 The Financial Express reported that Solidaridad had been working in the coastal regions to support soybean farmers through better seeds, training and market access, and that it had launched soy-based foods such as tofu with a local food producer.

The National Seed Board, which approved the variety, works under the Seeds Act 2018 (Act No. 6 of 2018, dated 28 January 2018), which replaced the Seeds Ordinance of 1977. The Act was made to regulate the production, sale, storage, import, export, exchange and other supply of the seed of any crop or variety and to set its standards; under section 8 the board issues registration certificates. With the board's formal approval on 11 November 2025, GAU Soybean 6 was released as a variety, after three years of selection and five years of trials on the coast.

Photo: United Soybean Board / Wikimedia Commons (CC BY 2.0)

Sources: Jagonews24 (1 March 2026), UNB (26 February 2026), The Financial Express (26 February 2026; 23 May 2025), Gazipur Agricultural University and its Department of Agronomy, Prothom Alo (5 March 2025), The Daily Star (26 March 2025, on the USDA Oilseeds and Products Annual), ACIAR South Asia Sustainable Development Investment Portfolio (12 August 2020), Food and Agriculture Organization of the United Nations (Irrigation Water Management Training Manual), Journal of Food Science and Technology (Takács et al., 2022), Banglapedia (Asiatic Society of Bangladesh), Seeds Act 2018, Wikipedia (World Vegetable Center)