Mekong Delta revives orchards as saltwater intrusion recedes

Thursday, 2020-07-09 11:35:25
 Font Size:     |        Print
 

A water saving irrigating model for dragon fruit in Long An Province. (Photo: NDO)
 Font Size:     |  

NDO – Local orchards in the Mekong Delta provinces have been revived after the prolonged drought and saltwater intrusion that severely affected local growers.

During the 2019-2020 dry season, the delta suffered severe damage to a vast area of fruit trees due to drought and saltwater intrusion. However, as the drought and salinity have decreased due with rains occurring in multiple localities, the restoration of affected fruit gardens is a top priority of local farmers.

At the start of this year’s dry season, it was forecast that about 130,000 hectares of fruit trees in the Mekong Delta (accounting for about 39% of the total) would likely be affected by drought and salinity, with the most affected being orchards of mangoes, bananas, dragon fruit, pineapples, citrus, longans, rambutans, durians, jackfruits and star apples. However, having anticipated such risks, the relevant ministries, agencies, local authorities and people deployed multiple measures to protect orchards and minimise the damages caused by drought and salinity. Therefore, the damage to fruit trees was very significant compared to that during the drought and salinity in 2015-2016.

To date, drought and salinity have affected the growth and development of about 80,000 hectares of fruit trees, concentrated mainly in the provinces of Long An, Ben Tre, Tien Giang, Tra Vinh, Vinh Long and Soc Trang. In some localities, due to fierce drought and salinity, thousands of hectares of orchards have been damaged. Chau Thanh District (Ben Tre Province) has lost about 50% of its rambutan, green skin pomelo and durian farming areas, of which, nearly 3,000 hectares have suffered damages of 30-70% while more than 1,200 hectares suffered damages of over 70%. In Tien Giang Province, there are about 4,799 hectares of durian, of a total of more than 13,500 hectares, have been affected during the last drought and saltwater intrusion.

After the drought and salinity, many farming areas of fruit trees have been depleted, posing a risk of tree death and reduced productivity as the orchards and soil have previously been contaminated with salinity. Therefore, experts have suggested that local farmers continue following information on drought and salinity to take a proactive response and apply recommended technical measures by functional agencies to restore plant growth and development.

A farmer in Tam Binh Commune, Cai Lay District, Tien Giang Province, irrigates with fresh water to save his durian trees during the recent drought and saltwater intrusion in the region. (Photo: NDO)

According to forecasts, due to climate change and water shortages, drought and saltwater intrusion in the Mekong Delta will continue to be unpredictable in the near future, affecting fruit production in Vietnam’s key farming region. Therefore, along with updating information on the drought and salinity situation to promptly stockpile fresh water and prevent saline intrusion, Mekong Delta localities need to continue investing in dike and irrigation systems to combat drought and saltwater, as well as protecting fruit-tree growing areas.

It has been suggested that the region should promote research on new crop varieties that are resistant to drought and salinity, while assessing the impact of climate change to propose directions to crop restructuring to adapt to drought and salinity.

From the practices of each locality and the whole region, local authorities should strengthen communication and dissemination of knowledge to farmers on adjusting the fruit-growing areas based on the salinity tolerance characteristics of each fruit, for example, the salt-sensitive susceptibility group, including avocado, banana, longan, papaya and durian, can suffer low salinity concentration from 0.5‰ to under 1‰, while the fruit group including citrus and guava has an average salinity tolerance ranging from 1-2‰, and the group with quite high saline tolerance, such as jackfruit, mango and soursop, can endure salinity ranging from 3-4‰.

Besides, it is necessary to store fresh water in canals and ditches. In some places, local farmers have stored fresh water in thick plastic bags and placed under the trees during the salty months. This model has shown its effectiveness. It is also important to apply economical irrigation models to minimise water loss and ensure water supply for plants when drought and salinity occur.

In fact, during the recent drought and salinity, local farmers applied such models as mentioned above, which helped to minimise damages to their orchards. In Soc Trang Province, local people have renovated freshwater storage ponds and covered grapefruit trees’ roots with straw and leaves to preserve moisture, helping to both prevent salinity intrusion and ensure water supply for the plants. In Hau Giang, many orchards have applied cost-effective irrigation systems that not only reduce labour costs but also save fresh water in canals for agricultural production.