KARACHI, Sept 9: The waterlogged and saline land of the country, especially that of lower Sindh, can be put to use and eventually reclaimed by planting halophytes.

Halophytes are plants adapted to growing in saline conditions.

Experts point out that land salination is one of the major desertification and degradation processes in Pakistan. About 6.3 million hectares are affected. About half of this lies in the Canal Command Area. Apart from a few localized areas, salt- affected soils are confined to the Indus plain.

Environmental biologist Dr M. Ajmal Khan of the botany department of the University of Karachi said that salinity in Sindh, as elsewhere in Pakistan, was high primarily because of two reasons. “First, our irrigation mechanism is faulty. The canals that criss-cross the landscape of Pakistan allow water to evaporate and seep through. Both evaporation and seepage lead to salinity. Second, base rocks in the country have a high composition of sodium chloride.”

Dr Khan said all over the world rainwater was collected in catchment areas and sent to other zones through either pipelines or cemented canals in a controlled manner. This method, he added, not only saved water from being wasted but also prevented salinity.

He said a shortage of freshwater had also disturbed hydrological balance at the seaboard, where sea intrusion was taking place fast. He added that sea intrusion was playing havoc with the highly productive land of lower Sindh.

When contacted, Dr Darrell J. Weber, professor of botany at the department of integrated biology in Brigham Young University, US, said that at first glance, saline land appeared to be worthless land. “Certainly the land is not usable by regular crops. Yet certain plants have adapted to growing on saline land. In fact some halophytic plants cannot grow without some salt in the soil. There is great potential for using saline land through the research and testing of high salinity plants on saline soils. The production of grass, and the extraction of seeds for cooking oil are examples of economic use of high saline plants grown on saline soils. The value of stabilizing the soil is another positive effect. This approach can have a huge impact in the world because it is estimated that one-third of the irrigated soil is becoming saline.”

Dr Khan enumerated the uses of halophytes. “Halophytes can be grown as forage for cattle in saline conditions. They can be employed to reduce of salinity of land. Apart from landscape gardening, they can be used as sand-binding plants, particularly in the wastelands of Balochistan. They can also be employed to generate oil seeds.”

The deputy director-general of the World Wide Fund for Conservation of Nature, Pakistan, Dr Ejaz Ahmad, said the halophytes could be used to plant as many mangroves as possible. “The area covered by mangroves in Pakistan has decreased over the years. At present, mangroves cover 160,000 hectares in the Indus delta and 7,500 hectares in three places in Balochistan. The major species of mangroves in Pakistan is Avicinna marina.”

Dr Khan stressed the need for funding research on halophytes in Pakistan. He said: “Botanists working on halophytes should be enabled to carry out research in the field in a more vigorous manner. They should also be allowed to set up a modern laboratory on the campus of Karachi University so that they could conduct tests.”