Effect of Compost, Lime and P on Selected Properties of Acidic Soils of Assosa

Abstract

A three-factor-experiment was conducted in the acidic soil of Assosa for two main growing seasons (2014-2015) to identify the effect of integrated application of compost, lime and phosphorus on selected chemical and physical properties of soil using maize as a test crop. The treatments consisted of compost (0 and 5 t ha^-1), lime (0, 1.5 and 3 t ha^-1) and phosphorus (0, 20 and 40 kg P ha^-1). Randomized complete block design with three replications was used. The analysis showed that there was significant (p<0.01) difference due to main and interaction effects of treatments on soil pH, OC, CEC and available P, total N, exchangeable acidity and exchangeable Al. Thus, the first season compost applied at 5 t ha^-1 increased the soil pH to 6.23, while the main effect of lime at 3 t ha^-1 increased the pH to 5.95. The interactions of the first season compost at 5 t ha^-1, lime at 1.5 t ha^-1 and P at 40 kg P ha^-1 showed the highest available P (15.04 cmolc kg^-1). The interactions of the first season lime (1.5 t ha^-1) with P at (40 kg P ha^-1) reduced the exchangeable acidity (0.36 cmol_c kg^-1) the highest, while the exchangeable Al was highly reduced by the main effect of compost at 5 t ha^-1 (0.32 cmol_c kg^-1) and interaction of first season with lime at 3 t ha^-1 (0.05 cmol_c kg^-1). The study suggested compost was as important as lime in increasing the soil pH and reducing exchangeable Al.

Keywords: soil pH, available P, exchangeable acidity exchangeable Al