Adapting rice to saltier water

How rice farmers are coping with rising sea levels

Salt water in coastal rice fields is a problem that is certain to get worse as sea levels rise.

Sri Lanka has experienced an increase in temperatures and relatively low rainfall for an extended period over the last 20 years, leading to a decrease in ground water levels. At the same time, increased sea levels have also caused sea water intrusion into coastal lagoons and estuary systems, causing the destruction and slow change of existing habitats.

Practical Action's work has included farmer-led trials of traditional and modern rice varieties which are saline-tolerant, temperature-resistant and pest-resistant.

Indigenous rice

Forgotten types of indigenous rice can offer a home grown solution to the increasing soil salinity. There are around 2,000 traditional rice varieties in Sri Lanka. Many are very high in nutritional value and have medicinal properties, and most are resistant to extreme drought conditions, diseases and pests.

These varieties were traditionally grown using natural inputs such as organic manure, and no chemical fertilisers or pesticides were used. Farmers with Practical Action have worked on a number of trials on various rice varieties to see if they could withstand salinity.

Dehigahalanda, southern Sri Lanka

For rice farmers in Dehigahalanda, in the Hambantota district of southern Sri Lanka, increased salinity in their water-logged fields was a grave problem, with yields dropping steeply. Some were getting less than half the expected yield. The farmers could not find a viable solution for the creeping salinity - aggravated by the 2004 Indian Ocean tsunami and a lack of fresh irrigation water - and feared that eventually their fields would be left barren.

40-year old S. Ranjith was one such farmer. Nearing desperation, his local farmers' organisation tried to appeal to various government institutions about their plight, but with little success.

Today Ranjith has managed to reverse his destiny. He is even producing seed paddy out of his one and a half acre field. The secret of his success does not lie in complicated engineering feats or advanced science, but in long-forgotten traditional rice varieties that have age-old ability to resist high salinity in soil and water.

Together with 16 other local farmers, Ranjith trialled ten different varieties of traditional rice through a programme of the National Federation of Traditional Seeds and Agri Resources and supported by Practical Action. For the first time, the farmers were given the choice of 'variety selection' and asked to score the different rice types according to duration of crop, plant height, grain quality and yield. Out of the ten, four varieties scored highest and were then promoted through farmer organisations as hardy, saline tolerant and high quality rice that were suited for coastal rice paddies.

Ranjith has cultivated his field for the third time with traditional varieties, shunning the hybrids promoted by the country's agricultural departments. His inputs are low-organic manure and less chemical pest control. Although traditional rice does not produce the yields of hybrid varieties, his profits remain high. Traditional rice is purchased at a higher price by the Federation and there is high consumer demand today for these rare rice types.

What's more, the application of organic fertilizer has begun to ease the soil salinity problem as well. "We were on the verge of abandoning our fields. The introduction of traditional rice has given a new lease of life to us and these fields," said Ranjith who is now a certified traditional rice grower and seed producer.

You can download further information on agriculture from Practical Answers, the technical information service of Practical Action, or you can ask a technical enquiry to the Practical Action staff via the online form.

Adapting Rice to Saltier Conditions

This brief outlines the approach of using indigenous verities of rice to develop salt tolerant crops for areas where soil salinity is an increasing problem.

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