Effects of Irrigation Systems on Physicochemical Properties of Soil at Different Depths: A Case Study at a Farm Near Ziway Lake, Ethiopia

Abstract

AbstractIrrigation, regardless of its possible negative impacts on the environment, is the prime choice to combat poverty and sustain food security. Changes in soil physicochemical properties and subsequent loss of productivity are the main challenges associated with irrigation practices. This study investigated the effect of furrow and basin irrigation systems on surface and subsurface soil physicochemical properties in comparison with properties in non‐irrigated fields. The soil properties were analysed as repeated measures using appropriate covariance structure. The results showed significant interaction between irrigation and depth on electrical conductivity, pH, Na+, Ca2+, Mg2+, soluble cations and organic carbon; but only the main effect of irrigation system was significant on K+, HCO3−, Cl−, SO42−, soluble anions and sodium adsorption ratio. Both irrigation systems had lower soluble salt content on the surface than at the subsurface layer with basin irrigation having slightly higher, but the non‐irrigated fields showed the opposite. The soil pH was high, particularly in the non‐irrigated fields, which could affect the availability of important soil constituents like Ca, Mg, Co, Cu, Fe, Mn and Zn, and increase Na hazard and boron (B) toxicity that would impair crop productivity. Therefore, the effects of the irrigation method on the soil properties should be well understood and appropriate precautions should be taken when choosing irrigation methods. © 2018 John Wiley & Sons, Ltd.