THE EFFECT OF ALTERNATIVE IRRIGATION WATER QUALITY IN VERTICAL SALINITY DISTRIBUTION IN THE SOIL GROWTH AND YIELD OF WHEAT (TRITICUM AESTIVUM L.)

A field experiment was conducted in the agricultural season 2019-2020 in one of the agricultural fields of the Irrigation Project Hilla - Kafel in (Babil province-Al-Hilla district-Sinjar village) in silty clay loam textured soil classified at Typic torrifluvent, to identify the possibility of using drainage water in the alternate and continuing irrigation with river water depending on the growth stages of wheat crop (class IPA 99) with the lowest effect on soil electrical conductivity (EC) and sodium adsorption ratio (SAR) values, the amount of freshwater saving with the least possible reduction in wheat crop were studied freshwater savings. Five irrigation treatments have been imposed: treatment continuous irrigation with riverwater for all stages of growth (C-1), treatment irrigation with Salinity Drainage Water for yield formation Stage and River water for rest growth stages (C-2), treatment irrigation with Salinity Drainage Water for flowering Stage and River water for the rest growth stages (C-3), treatment irrigation with Salinity Drainage Water for vegetative development Stage and River water for the rest growth stages (C-4), and treatment continuous irrigation with Salinity Drainage water for all stages of growth (C-5). The results of the study showed that there were significant differences for soil electrical conductivity (EC) and sodium adsorption(SAR) and reached the highest value of electrical conductivity at the treatment C-5 and the lowest value was under the influence of the treatment Irrigation C-1, and not significant differences between the averages of the values of the characteristic under study under the influence of irrigation coefficients C-3, C-2, C-1 and C-4 when compared with each other because all treatments were watered in the same quality of water (river water) but the treatment C-5 significantly exceeded on the rest of the transactions at the beginning of the growth season because it was watered with a salt drainage water. At the end of the growing season, there were significant differences between the quality of water for different irrigation coefficients, which is due to the different quality of irrigation water used between them during each stage, and the rate of increase in status under study at this stage compared to that at the beginning of the growth season was 23.77% and 51.37% for C-1 and C-5, respectively. Treatment C-4 had less significant effect on the amount of salt accumulation after the treatment of C-1 river water irrigation for all stages of growth and followed by alternating irrigation C-3, the depth factor, there has been an increase in soil salinity with increased salinity of irrigation water and frequency of irrigation with the same water quality with approaching of the surface. As for SAR it was consistent with the result of electrical conductivity and at the same growth stage, and this result confirmed the expulsion relationship between them. The results also showed that there were significant differences in the number of tillers, the grain yield and the biological yield of the wheat crop.