Comparison of biomass and nutritional value of different Salicornia spp. under irrigation

Due to the limitations of freshwater resources, using other sources, such as drainage and seawater, is inevitable for fodder production by halophytes. Salicornia species are the most salt-tolerant plants (Eu-halophytes) that grow directly in seawater. The plant shoots could be used with common fodder plants for livestock feeding. After oil extraction, Salicornia seeds contain 43% protein. The research objective was to select the most suitable Salicornia species in terms of yield and fodder quality in Bushehr Province.

To investigate the yield and nutritional value of Salicornia, this research was carried out on Salicornia bigelovii and four native ecotypes, including Bushehr ecotype (S. sinus persica Akhani), Central Plateau ecotype (S. persica Akhani subsp.Sersica), Urmiai, Gorgan and Markazi ecotypes at the Salinity Research Station of Bushehr Province. The area is characterized by a warm and wet climate with low annual precipitation (217 mm) and high annual average temperature (24.0 °C).A three-replicate randomized complete block design was used. The field was planted by seed sowing and irrigated with Persian Gulf water (60 dS m-1).Aerial plant samples were prepared at vegetative growth to determine the fodder nutritional value of different plant species and ecotypes. Values of aerial ash, crude protein, non-protein nitrogen content (NPN), acid detergent fiber (ADF), neutral detergent fiber (NDF), acid detergent lignin (ADL), and metabolizable energy were measured. At the end of the growing season, an area of one square meter was taken from each experimental unit to determine biomass dry weight. Data were analyzed using SAS software, and mean comparisons were performed using Duncan's test at the 5% level.

Results showed a significant difference in dry biomass between different Salicornia species and ecotypes. Bushehr, Central Plateau, Urmia, Gorgan ecotypes, and S. bigelovii dry biomass amounts were 18.29, 14.64, 4.22, 4.60, and 6.71 tons ha-1, respectively.The highest and lowest values of shoot ash were 54% and 46% of dry matter for Busher and S. bigelovii, respectively. There was no significant difference between species and ecotypes in crude aerial protein. The crude protein content of aerial varied between 6.9 in the Central Plateau and 8.6 in Bushehr ecotypes.The metabolizable energy of fodder was estimated between 5.17 and 5.74 MJ kg-1 of dry matter; the lowest and highest were attributed to the S. bigelovii and Urmia ecotypes, respectively. The highest and lowest cell wall indicators of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) were related to the Gorgan and Bushehr ecotypes, respectively. Fodder gas production for different Salicornia species and ecotypes was significantly lower than for alfalfa during incubation. Among different species and ecotypes of Salicornia, the highest and lowest gas production rates were related to S. bigelovii and Urmia ecotypes.

To provide livestock fodder on the province's coasts, the Bushehr ecotype (Salicornia sinus persica Akhani) is generally recommended for planting due to its high yield and adaptability to the region. However, due to the relatively high ash content of the plant, only a part of the livestock feed could be provided by the plant fodder. Therefore, to properly use the plant fodder in livestock feed, it is necessary to determine the daily consumption of fodder in the ration.