Use of Sea-Water Dilutions for Irrigation in Sand Dunes in the Northern Coasts in Libya

Abstract

An experiment was conducted to investigate the possibility of growing some crops in sandy soils irrigated with sea-water dilutions, plant species tested were: alfalfa, barley, beets, flax, safflower, and wheat. Sea-water dilutions employed were: 10, 20, 30, 40, 50, 70, and 100 % besides the control in which fresh water was used. The experiment included lysimeters, pots, and nursery plots. Plants were grown in a highly permeable sandy soil taken from Tajora sea shore.The experiment was carried out for a period of 78 days during which the growth of plants was observed and recorded. At the end of the experimental period, samples were taken from beets only. These samples were then properly dried and analyzed for Na, K. P, Ca, and Mg.Growth observations showed the thresholds to salinity in irrigation water to be: 4.150, 12,300, and 21.000 ppm. of T.D.S. for flax and safflower, alfalfa, beet and wheat and barley, respectively.The dry weight of beet plants increased by the use of sea-water dilutions. Maximum increase was obtained at the 107o dilution ratio. This was attributed to the probable presence of ions of certain elements at a higher concentration in sea-water than in fresh water.The plant contents of almost all nutrients tested were increased when sea-water was included in irrigation. However, the concentration of the same nutrients was not materially affected. Despite the presence of sodium at a high concentration in the sea-water dilutions, no corresponding increases were shown in the plant uptake of that element. Potassium behaved in a reverse manner. Although its concentration in sea-water dilutions was low. the plant uptake of K was relatively high.
These findings may be considered promising in using sea-water dilutions for the irrigation of some agricultural crops in Libya.