Seasonal chemical composition of saltbush in semiarid grasslands in Jordan

Abstract

Saltbush (Atriplex halimus L.), a native shrub which is adapted to arid rangelands, was transplanted to the semiarid grassland at Jordan University of Science and Technology Campus in 1986. Our objective was to determine the seasonal changes in the chemical composition of the annual growth of leaves and stems of saltbush (Atriplex halimus L.) during 1995-96 and 1996-97. A strong positive correlation was found among P, Ca, crude protein, and nitrogen free extract and a strong negative correlation was found between fiber and P, Ca, crude protein, and nitrogen free extract. Nitrogen free extract (NFE) had a strong positive linear correlation with P, Ca, and crude protein. P, Ca, Ca:P ratio, crude protein, and NFE contents were found to be higher in leaves than in stems on all the occasions. Leaves had relatively higher concentrations of P, Ca, crude protein, and NFE during the growing season (February to April). Crude protein of leaves reached its maximum in March (22.7% ). The concentrations decreased, however, to 15% during the dry period (June to October). Crude protein content of stems ranged from 11.3 to 12.2%. Fiber content of leaves was lowest during February and March (16.9 to 18%), and reached maximum values during August and October. Saltbush is a good protein source for sheep during the dry season; however, P content would not meet nutritional requirements of ewes.