Groundwater salinlty and depth effects on soil salinlty in a furrow lrirrigated area in Kenya

Abstract

The effect of groundwater salinity and depth on soil salinity was investigated in a furrowirrigated area of Kenya dqring consecutive wet and dry seasons. The groundwater salinity was significantly (P < 0.05, R2 = O.75-O.88) related to soil salinity when the groundwater depth fluctuated within O-1 m depth in both seasons. When the groundwater remained below I m, the relationship was not linear. This meant that when saline groundwater existed within I m from the soil surface, soil salinity ensued even when low salinity (electrical conductivity = O.2a dS m-l in the dry season) irrigation water was used. The depth of the groundwater table was different in each season. In general, deep levels occurred during the dry season while shallow water tables existed during the wet season. Thus, leaching of excess salts by rainwater was likely to be compounded by the shallow saline groundwater table and therefore not feasible if the saline groundwater table was <1 m regardless of season.