Abstract

This study intended to characterize the physicochemical characteristics of soils and irrigation water qualities under four land use types of Babile low lands in eastern Ethiopia. Four profiles opened from non-cultivated (profile 1), two irrigated cultivated (profile 2 & 3) and none irrigated cultivated lands (profile 4) for laboratory analysis. The results revealed relatively variation in morphological and physicochemical properties of soils. The soils are clay to sandy in texture with bulk density values ranging from 1.12 to 1.32gcm-3 and the clay contents significantly affected both by land use type and profile depth. The basic infiltration rates and saturated hydraulic conductivities of the soils were moderately slow. The soils were moderately alkaline to alkaline in reaction (pH 7.89 to 8.54), the mean soil electrical conductivity of saturated pest (ECe) were greater than 4dSm-1 and significantly affected by land use type and profile depth. The exchangeable cations determined had clear distinctions on the distribution of adsorbed cations; adsorbed Na+ was higher on the exchange site of the irrigated soils than the non-irrigated soils. Medium to very high cation exchange capacity (34.26 to 38.92cmol (+) kg-1) was recorded. Exchangeable cations (Na, K, Ca, Mg), Exchangeable sodium percentage (ESP), sodium adsorption Ratio (SAR) and Cation Exchangeable Capacity (CEC) were significantly (P<0.05) affected by land use types and profile depth. In line with this, two irrigation water sources were analyzed, the result revealed that both water sources contained medium to very high dissolved salts. On the other hand, the residual sodium carbonate (RSC) of Errer River (1.25 to 2.50meqL-1) and ground waters (>2.50meqL-1) were marginal and unsafe for irrigation, respectively. It could therefore be generalized that, beside to natural conditions, irrigation water could be the main source for the occurrence of saline sodic soils in the irrigated lands of the area. Hence, introduction of locally available organic and inorganic reclaiming materials may improve the productivity of the saline sodic soils of the study area for the resource poor farmers.

Keywords

electrical, conductivity, saturated, pest, sources, exchangeable, sodium, percentage, sodium, capacity, atomic, ultimately, organic, salinity, soil