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.

摘要

本研究的目的是调查河马草除其在埃及伊斯梅利亚运河沿线的草料质量外，还可以隔离其生物质中无机和有机养分的潜力。选择了八个地点（包括6个受污染的地点和2个未受污染的地点）进行季节性植物，水和沉积物调查。估算了植物组织的营养成分和营养价值。夏季记录到的地上生物量最高，而冬季记录到的最低。在冬季，该植物的Na，K，N和Mg含量最高，而在春季和秋季，其P和Ca含量最高。此外，钠，钾和P具有最高浓度（176.7毫克千克^-1，206.9毫克千克^-1和地下的器官中的N，Ca和Mg（分别为0.9％，1.6％和0.5％）和1.1％）。被调查元素（Na除外）的含量在受污染和未经污染的运河中是可比的，没有显着差异。地上部分在夏季的乙醚提取物含量最高（1.1％），在春季的粗纤维含量最高（60.2％），在冬季的总蛋白含量最高（5.6％）。地下组织具有最高的代谢能，可消化能和净能（2.4、2.0和1.0 Mcal kg ^-1） 在冬天。相比之下，地上枝条在冬季的可消化粗蛋白含量最高（1.7％），在春季的总能量最高。无论是地上部分还是地下部分，未经污染的河马草的营养价值均大于受污染的河马草的营养价值。河马草可以隔离大量的养分。因此，该植物可通过在生长季节收获地上的生物质来恢复富营养化的水。此外，河马草的地上芽还可以用作奶牛，山羊，肉牛和绵羊的饲料。