M.Y. Helmi’s scientific contributions

A pot experiment was conducted at the greenhouse of Soils, Water and Environment Research Institute, Giza, during the two winter seasons of 2007/2008 and 2008/2009. The study aimed to evaluate the effect of different strategies of reuse of low quality drainage water (drainage water, alternating, blended with Nile water), some, amendments application either to the soil (gypsum) or to the irrigation water (Ammonium Thio Sulfate ; ATS) and small split application of fertilizers through irrigation water at high rates on both soil properties and wheat crop response to water salinity. The irrigation water salinity levels were, 0.36, 4.42 and 2.34 dSm-1 for Nile water (control), drainage and blended water, respectively. The NPK fertilizers were applied at the rates of 0, 100 % and 125 % from the recommended doses, the high rate was applied to alleviating soil salinity stress. The obtained results indicated that soil salinity (EC e), sodicity (SAR and ESP) tended to increase with increasing salinity levels of irrigation water, i.e., from 5.41 to 6.00, 7.22 and 9.87 dSm-1 in the first season and from 5.62 to 6.64, 7.69 and 12.74 dSm-1 in the second season for Nile, alternating, blended and drainage water, respectively. The values of soil SAR and ESP took place similar trend for EC e values. Application of gypsum and ATS led to reduce the hazardous effect of irrigation water salinity and sodicity. These favourable soil amelioration were positively reflected on wheat yields of grain and straw and NPK uptake. These benefit effects were maximized by increasing the NPK doses from 100 % to 125 %.