EFFECTS OF SALINE WATER FLUX ON CHANGES I EFFLUENT QUALITY, LEACHING FRACTION, EVAPO - ATION AND SALT LOAD IN COARSE - TEXTURED SOIL

TwO laboratory experiments were conducted on sandy soil columns tp
quantity the dynamic changes of effluent salinity (Ee) and sodium adsorption ratip
(SAR) as well as leaching fraction (IF) and salt load as a result of using water with E<i:
0.5. 1.2.1.8.2.37. and 3.6 dS.m·^'. Downward Aux simulates normal surlace irrigatio
while upward flux simulates subsurface irrigation. The results indicated Ihat (herr
were polynomial relationships between EC and SAR of leachate and elF) and lim!
when the EC values of applied mixing water were> 0.5 ds.m". Exponential relation
between EC. SAR and IF wilh time were obtained when the EC of applied water wa
0.5 dS.m·^l. Linear regression equations between the cumulative evaporation and the
lime of upward nux were obtained under different salinity levels of applied water. The
contribution of upward and downward saline water to build up salt load in soil column$
was clear. The maximum values of osmotic potential in the surface layer were 0.83
and 0.58 bar as 8 result of upward and downward nux of saline water (3.6 dS.m·\
respectively. Thus the adverse effects on soil properties as a result of increased salt
concentration can be minimized by controlling the mixing ratio. It was concluded that
the use of poor quality water in irrigalion. particularly in coarse - textured soil.
becomes an efficient means in a scare resource without risks due to mismanagement
this requires appropriate sa Unity by mixing agricultural drainage water with canal
water. Best soil and water management practices and aoequate leaching are also
required 10 keep suitable sail balance in a given soil depth. I