Effect of Bypass-Flow on Leaching of Salts in a Cracking Soil in the Nile Delta

Salinity is a major threat to the sustainability of irrigated agriculture in arid and semi-arid regions. Leaching primary measure for removing excess salts from root zone, but not all water applied soil surface contributes removal salts. In clayey soils, bypass flow along cracks can occur without being mixed with saline pore matrix. To present field dataset quantitatively evaluate contribution leaching salts, sampling monitoring groundwater discharge tile drain were carried out farmland having cracking Nile Delta. The electrical conductivities 1:2 extracts measured salinity soil. first evidence occurrence significant through was water, which nearly triple that shallow outflow drainage. Second, difference zone before after paddy rice cultivation significant. Third, gradient table very small. spite low saturated hydraulic conductivity. Fourth, dropped just irrigation or rain. These results indicated played role drainage process soil, half bypasses