Evaluation of the nutrient status and forage quality of the hippo grass (Vossia cuspidata (Roxb.) Griff.) along Ismailia canal, Egypt

Abstract

The present study aims at investigating the potential of the hippo grass for sequestering inorganic and organic nutrients in its biomass, in addition to its forage quality along Ismailia Canal, Egypt. Eight sites including 6 polluted and 2 unpolluted were selected for a seasonal plant, water and sediment investigations. The nutrients and nutritional value of the plant tissues were estimated. The highest aboveground biomass was recorded during summer, while the lowest was in winter. The plant had the highest contents of Na, K, N and Mg during winter, while P and Ca during spring and autumn, respectively. Also, Na, K and P had the highest concentrations (176.7 mg kg−1, 206.9 mg kg−1 and 1.1%) in the belowground, while N, Ca and Mg (0.9, 1.6 and 0.5%) in the aboveground organs. The contents of the investigated elements (except Na) were comparable in polluted and unpolluted canals with no significant differences. The aboveground parts had the highest values of ether extract (1.1%) during summer, crude fibres (60.2%) during spring, and total proteins (5.6%) during winter. The belowground tissues had the highest values of metabolized, digestible and net energy (2.4, 2.0 and 1.0 Mcal kg−1) during winter. In contrast, the aboveground shoots had the highest amounts of digestible crude protein (1.7%) during winter and gross energy during spring. The nutritional value of the hippo grass from unpolluted canals were greater than polluted ones for both above- and belowground parts. Hippo grass can sequester large amounts of nutrients. Consequently, this plant can be used in restoring eutrophic water through harvesting the aboveground biomass during the growing season. Besides, the aboveground shoots of the hippo grass could be used as a forage for dairy cattle, goat, beef cattle and sheep.