Environmentalists have warned that vast stretches of coastal arable land in Bangladesh may become barren because of an alarming rise in salinity due to a climate change-triggered rise in sea level.
Researchers say none of the existing varieties of salinity-tolerant rice can stand the level of salinity that has affected some of the coastal districts. In fact, the best salinity-tolerant variety that could be developed was nowhere near the level already reached, scientists said. Bangladesh Rice Research Institute (BRRI) and Bangladesh Institute of Nuclear Agriculture (BINA) have invented seven varieties of rice that can stand salinity of up to 8 deci Siemens per metre (dS/M).
However, studies have shown that salinity in more than half of the arable lands in five coastal districts have gone well past that level. According to a study conducted by the Soil Resource Development Institute, the level of salinity in 79,000 hectares of affected land in the Khulna district was identified as S3 – meaning the salinity ranged from 8.1dS/M to 16dS/M. Similarly, 62,000 hectares in Patuakhali, 99,000 in Satkhira, 62,000 in Bagerhat and 38,000 hectares of salinity-affected lands in Barguna were also tagged S3. The study also showed that in 1973, some 8.33 lakh hectares of land in 19 coastal districts were salinity-affected. Now, the figure stands at 10.2 lakh hectares.
Jiban Krishna Biswas, director general of BRRI, said paddy can be made tolerant to 12dS/M of salinity, at best. Moreover, the salinity-tolerant breeds developed by the BRRI and BINA have failed to gain popularity among the farmers because of their low productivity and high irrigation dependency. Agricultural Economist Prof Shamsul Alam, a member of the Planning Commission, said: “Farmers opted for those varieties that were comfortable to produce and rejected those that were substandard in quality and lacked financial viability.” He also said: “BRRI 28 and BRRI 29 have been the most popular [non salinity-tolerant hybrid] varieties for the last 20 years because they were farmer-friendly and ensured more production for less irrigation.” Jiban Krishna suggested that coastal growers should change their paddy farming habits and opt for crops such as soybean, maize, barley and sugarcane.
The traditional varieties of most crops can withstand salinity of up to 0.7dS/M. Dr Atiq Rahman, executive director of the Bangladesh Centre for Advanced Studies, said current trends indicate that salinity is going to affect bigger stretches of coastal lands with higher degreesof intensity. He said: “Because of global warming, sea levels have been rising. Since Bangladesh is a delta, the salinity of sea water is pushing up the rivers, making the adjacent lands highly saline.” The situation is nothing short of a disaster, said Atiq, who worked as a climate scientist with the International Panel on Climate Change (IPCC).
Specialists also said the situation in Bangladesh is unique. Other major rice-producers such as the Philippines are mostly affected by harsh weather conditions – another effect of the global climate change.
Written by Abu Bakar Siddique, collected from the Dhaka Tribune
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