Abstract
The present study aims to assess the role of Phragmites australis in the accumulation of elements and nutritive value to test its suitability to use as a potential forage plant for cattle, goats and sheep in lake Burullus, Egypt. Different plant organs were collected from the sampling sites for estimating seven heavy metals (Mn, Pb, Co, Cu, Cd, Zn, and Fe) and six nutrients (Na, K, Ca, Mg, P and N) as well as the physical and chemical characteristics of water. In addition, seven organic constituents (total ash, carbohydrates, total lipids, crude fibers, crude protein, digestible crude protein and total digestible nutrients) were estimated, and three nutritive values (digestible energy, metabolized energy, net and gross energy) were calculated. The results revealed that an increase in heavy metals accumulation in the rhizome and decreased in the order of rhizome > stem > leaves. Moreover, positive linear relationships were found between these heavy metal concentrations in plant organs and those in water. Thus P. australis can serve as a good accumulator and bioindicator of heavy metals in the polluted water bodies. On the other hand, the nutrients are decreased in the order of stems > leaves > rhizomes. The leaves had the highest total ash, crude protein, digestible crude protein, digestible energy, metabolized energy and net energy, while the stems had the highest total carbohydrates and crude fibers. Therefore, the results revealed that the underground rhizomes had the ability to accumulate heavy metals and thereby used as a phytoremediator; while its aboveground parts had the highest nutrient and nutritive values, which consider the plant as good forage for animals.