Effects of Treatment Application Rates (FYM and Gypsum) and Pore Volume Leaching Water on Exchangeable Sodium and Saturated Hydraulic Conductivity of Saline Sodic Soils of Babile District, Eastern Lowlands of Ethiopia

Abstract

Incubation and laboratory experiments were conducted to evaluate the effect of FYM, gypsum and pore volume (PV) of water on ESP and Ksat of saline sodic soils. Factorial combination of three rates of FYM (0, 20 and 30 ton ha-1), four rat of gypsum (0, 50, 75, 100 and 125% GR) and three PV of water (1.0, 2.0, 3.0 and 4.0) were applied into the soil in complete randomized design with three replications. The soils were incubated using a plastic pot for a week followed by leaching with various PV of water. The data obtained subjected to analysis of variance. Results indicated that sole application of gypsum at different rates and their combination with FYM significantly decreased the ESP of the soil compared to FYM and the control. However, larger exchangeable Na released and then decreased the soil ESP with the use of combined FYM and gypsum treatments than sole application of gypsum for every increment in applied PV of leaching water. Similarly, the Ksat of soils was higher in combined than sole application of FYM and gypsum for all applied fixed PV of leaching water. On the other hand, increasing sole application of FYM and gypsum increased the Ksat of soil and the numerical values were significantly (P < 0.05) higher than the control but lower than the different combinations. Though, the Ksat of soil increased with increasing rates of applied FYM and gypsum; these values showed decreasing trend as PV of leaching water increased. In general, the interaction effects of different levels of FYM, gypsum and PV of water were significant (P < 0.05) in improving the ESP and Ksat of the saline sodic soils of Bisidimo. In conclusion, among the various treatments considered, combinations of 20 tons FYM ha-1 with gypsum (50, 75 and 100% GR) rates and leaching up to three PV of water are adequate to reclaim saline sodic soil to permissible limit and then theses combinations are recommended for resource poor farmers. The experiment was laid down in a completely randomized design with two replicates.