Date of Award

2004

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Environmental Science

First Advisor

Dr. Ahmed AI-Massoum

Second Advisor

Dr. J. Scott Angle

Third Advisor

Dr. Ahmed EI-Tayeb Osman

Abstract

Experiments were conducted at the International Center for Bio saline Agriculture (ICBA) in Dubai to evaluate the growth and productivity of some locally grown grass species; Rhodes grass (Chloris gayana L.) var. Katambora, Pioneer, and Callide; and Panicum grass (Panicum maximum) var. Green, and Gatton over a range of irrigation levels (1 gal/hr and 1.3 gal/hr), and water salinity (5 dS/m, 10 dS/m and 15 dS/m). The effect of different quality of water in respect to the salinity levels would provide information about water use efficiencies and soil salinity over a period. Growth and biomass productivity of the test species were periodically monitored and measured for every harvest (plant height, total tiller no., leaf length, internodes length, total fresh weight per m2, total dry weight per m2, leaf dry weight per m2, leaf area per m2, stem dry weight per m2, leaves fresh weight per m2, stem fresh weight per m2, leaf area per m2, and fertile tillers no. per m2). Forage quality of these species were evaluated to determine organic (protein, ADF (acid detergent fiber) and NDF (neutral detergent fiber), dry matter, and ash) and inorganic contents (Ca, K, Na, Cl and Mg) of the harvested materials. In order to assess the effects of salinity irrigation water on salt accumulation, soil samples were collected at different depths of the soil (30 cm and 60 cm) from various sampling spots of the trial and analyzed for salt content, and correlated with forage productivity and quality. Results showed that some of the plant measurements were not affected by salinity, although it has shown resistance to salinity. For example, at cut no. 2, at irrigation 1.3 gal/hr, Rhodes grass (Callide) has a fresh weight of 1421 g per m2, 1205 g, 1086 g, at salinity levels 5, 10, 15 dS/m respectively. The above results showed that the plant was significantly affected by salinity (P>0.05) and slightly decreased its fresh weight while the salinity increased three times. In conclusion, plant was significantly affected by salinity, and in the meantime, it has produced a proper fresh weight. There was a significant difference between cuts, cultivars within the same cut or other cuts, according to interaction with the environment, or the implemented salinity or irrigation level.

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