JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, cilt.166, sa.5, ss.621-624, 2003 (SCI-Expanded)
The objective of this study was to determine the effects of consecutive application of gypsum dissolved in leaching water on hydraulic conductivity of a saline-sodic soil. Drainage type plastic columns with a 10 cm diameter were used in this laboratory experiment. Soil depth within columns was 30 cm with an average bulk density of 1.38 gcm(-3). Leaching water was applied in six equal portions. Total gypsum was applied at 1, 3, and 5 portions after dissolving in leaching water. In dissolution, equal (1.273 + 1.273 + 1.273 Mg ha(-1)), increasing (0.637 + 1.273 + 1.910 Mg ha(-1)) and decreasing (1.910 + 1.273 + 0.637 Mg ha(-1)) quantities of gypsum were used. Results were compared with the control treatment, in which total amount of gypsum were mixed with surface layer of soil column before leaching. Hydraulic conductivity of soil increased in all treatments. The maximum hydraulic conductivity value was obtained at consecutive application of gypsum at decreasing quantities.