Salicornia brachiata – a boon to saline soils
By: G.M. Narasimha Rao*
Mangroves are evergreen tidal forests between land and sea. While Sunderbans are the second largest mangroves in the world, Godavari mangroves are the second largest mangrove ecosystems in India. In mangrove forests there are three different groups of communities coexisting with each other; those are true mangroves, associated mangroves and halophytes. Halophytes are a group of salt tolerant, drought resistant plants which grow in transitional zone in between terrestrial plants and mangrove plants. Halophytes are used as food, fodder, fertilizer and have several medicinal applications by the local communities since long back. Among these halophytes Salicornia brachiata is one of the most important plant materials for various applications in daily life. Plants, popularly known as Sea asparagus are cooked and eaten or pickled. It is also a good fodder for cattle, sheep and goat. Plant material is also used as raw material in paper and board factories. Its seeds yield high quality edible oil which is highly poly-unsaturated and similar to safflower oil. Recent investigations revealed that this halophyte is one of the potential plants for extraction of bio-fuels. Salicornia brachiata is a halophyte which occurs along the estuarine habitats of the tropical and temperate water of the Globe. In Andhra Pradesh abundant biomass was reported in the estuarine regions of the Godavari estuary. Department of Science and Technology, Government of India, sponsored a project entitled “Distribution, cultivation and conservation of Salicornia brachiata: A potential halophyte for the bio-fuels. Aqua culture in coastal regions of Andhra Pradesh was instrumental for changing the life styles of local communities, but on the other hand there was a problem with intrusion of salt water into the paddy fields. During this period due to wide spread viral diseases in shrimp cultivation some of these aqua cultural units were closed. Besides, there is plenty of saline soil resources which are available along the estuarine habitats of the Andhra Pradesh. Land, which had been unused will be reclaimed allowing for new coastal communities, more jobs and with benefit the environment. Salicornia brachiata is able to grow and give good return in saline soils only. Cost of its cultural operations is significant and no technical guidance is needed for its commercial cultivation. With minimum manpower, one can get good results with support of the companies for buying this product. The commercial production of Salicornia brachiata with sea water can contribute towards balancing the Earth’s carbon dioxide cycle having impact as the ‘Green house effect.’ During our investigations we have conducted the hydrographical studies, sediment analysis and cultural investigations on this halophyte to understand the suitable environmental parameters for maximum productivity of this plant in commercial scale. Soil samples were collected from different stations of the estuary to collect the information on soil salinity, soil pH and ratios of silt, clay and silt content in the sediments. Soil salinity varied from 24 to 34 ppt in all stations, pH of the soil samples varied from 7.6 to 7.9. Soil analysis shows the sand content varies from 9.0 to 18, silt 46 to 61 and clay 28 to 38. Salicornia brachiata is seasonal herb which completes its life cycle in eight to nine months. Maximum productivity was reported when salinity was in between 23 to 35 ppt, minimum percentage of sand and silt content was more than 50%. In the Godavari estuary maximum density (2884 plants/hectare) was reported for Salicornia populations in the Chollangi station followed by Pandi (2446 plants/hectare).In cultivation, biomass productivity was 15,000 to 19,000 kgs per hectare and seed production 1200 to 1800 kgs per hectare.
*Department of Botany, Andhra University, Visakhapatnam-530003