VIETNAM – Flooding in the lower Mekong Delta is becoming more intense, frequent and complex to control due to climate change, say researchers. The 17 million farmers living on the Delta in Vietnam’s southern-most tip – where 60 percent of the country’s rice is produced – need solutions.
As the government contemplates costs of up to $2.1 billion to protect crops and people from weather extremes and salt water intrusion, rice researchers are trying to equip farmers with more robust rice varieties.
Rice farmer Ho Thai Benam’s crop was hit by disease earlier in the year. “I have children studying in the city and with low rice productivity I don’t have enough money for their tuition,” she said.
She is looking for rice that is disease-resistant, high-yielding and fetches a good price, she said. After a workshop in her community about improved rice varieties, she selected new seeds that should help her protect her crop from disease and flooding, and boost yields.
She is among hundreds of farmers targeted by an Australian Centre for International Agricultural Research-funded project investigating challenges facing farmers including lack of suitable rice varieties resistant to flood and salt water tolerance.
Climate Change Affecting Land Use in the Mekong Delta: Adaptation of Rice-based Cropping Systems (CLUES) is led by researchers at the International Rice Research Institute and part of global efforts to tackle climate change in the region under the international agricultural research group CGIAR’s Research Program on Climate Change, Agriculture and Food Security (CCAFS).
RICE TO BEAT EXTREMES
Using a scientific process known as marker assisted back-crossing, researchers identified favorable traits in well-adapted rice varieties, such as high yield, and combined them with other favorable traits to create hardier rice varieties.
In total, 36 single and multiple crosses have been made to combine ability to withstand being submerged and salinity tolerance with high grain quality. So far 2,768 kilograms of the new seed have been released to farmers.
Professor Nguyen Thi Lang, at the Delta’s Cuu Long Rice Research Institute, explains: “We release the improved rice varieties to local breeding and agricultural extension centres, which multiply and provide them to farmers in their areas.”
According to Ngo Dang Phong, a coordinator of CLUES, “flooding and sea water intrusion are two of the biggest threats to rice producers in the lower Mekong Delta.”
It is projected that by 2030, salt water could contaminate 41 percent of the Delta.
Such changes “threaten farming and social systems now more than ever,” he added.
CLUES researchers have mapped hot spots of flooding and salinity intrusion, and assessed the impact of infrastructure development on the lower Mekong River since 2011.
They have advised farmers to intercrop rice with crops like cucumber, which cope well with different soil types, have low water requirements and grow quickly, to provide income between crops.
Experiments on different management techniques also revealed that alternatively flooding and draining fields can slash water use by about 20 percent and save irrigation-associated fuel and labor costs of about $120 per hectare. The changes also can cut methane emissions from continuous flooding rice production in half.
Such climate-smart practices are more realistic than just switching crops, which is not an option for many farmers like Ho Thai Benam. Rice has been grown for generations and is a central food security crop and export earner in Vietnam, fetching around $2.9 billion in earnings in 2013.