Evaluation of the Nutrient Status of Some Hydrophytes in the Water Courses of Nile Delta, Egypt

Abstract

The nutritive values of three dominant hydrophytes along the water courses in Nile Delta, Egypt (Echinochloa stagnina, Eichhornia crassipes, and Ceratophyllum demersum) were evaluated in terms of estimating their phytomass, organic, and inorganic chemical compositions. Shoots were collected seasonally from 25 permanent stands representing the distribution of the three species along 15 canals and 10 drains distributed in 5 localities within the Nile Delta. Living and dead parts and total phytomass were estimated. Their inorganic (Na, K, Ca, Mg, P, Cu, Mn, and Pb) and organic (carbohydrates, total nitrogen, total protein, ether extract, digestible nutrient, digestible energy, metabolized energy, and net energy) contents were estimated. The vegetative phase of E. stagnina extended during winter, spring, and summer, while it is flowering and fruiting during autumn. On the other hand, E. crassipes and C. demersum attained their maximum flowering during spring and maximum fruiting during summer, while maximum vegetative phase during autumn and winter. E. stagnina had the highest mean annual phytomass, while C. demersum had the lowest. The living parts of C. demersum had the highest concentrations of Na, Ca, and Mg, while the living parts of E. crassipes had the highest of K and N. C. demersum had the ability to accumulate more concentrations of heavy metals than the other studied species. E. crassipes had the highest values of total carbohydrate and total proteins, while E. stagnina had the highest of crude fibers, and C. demersum had the highest of ether extract and ash contents. The living parts of E. crassipes and C. demersum were considered as excellent forages, while the dead parts of all species and the living parts of E. stagnina were evaluated as poor forage.