English abstract
Soil amendments are used to improve the water and nutrient holding capacity of coarse textured soils, and alleviate problems of infīltration and percolation in fine textured soils. The effects of a gel-forming absorbent copolymer and peatmoss as soil amendments, on intermittent evaporation, moisture distribution, and salt redistribution through saline-sodic fine textured soil columns, were investigated. Two water qualities (3,600 and 560 µS/cm), two intervals of water applications (5 and 10 days) and two application rates (3 and 6 mm d-1) were used in the study. The results indicated that after a threshold period which was longer for the lower rate of water application, the cumulative evaporation (E) increased with the decrease in irrigation interval and the type of soil amendments added in the order of control, pcatmoss, and the absorbent copolymer. The absorbent copolymer conserved 30% more water than the untreated soils. In accordance with previous findings, E was found to be a linear function of the square root of time (i.e., E = c/t0.5), where c under the experimental conditions was largely determined by the amount of water applied per irrigation and the type of soil amendment added. Salt and soil water distributions were governed by the amount of water conserved. Within the profile, peatmoss was significantly effective in leaching salts. The quantity of water applied at a time, rather than the cumulative amount, seemed to affect water conservation; whereas the cumulative amount of water applied during the span of study significantly affected EC and SAR re-distributions. The water quality had no significant effect on either evaporation or salt re-distribution under the experimental condition.
