Application of Compost, Lime and P Fertilizer on Selected Soil Properties and P Use Efficiency of Maize in Acidic Soil of Assosa, Western Ethiopia

Soil fertility loss due to soil acidity is a major constraint for crop production in western Ethiopia. A study was conducted in the acidic soil of Assosa for two main growing seasons (2014 and 2015) to assess the effect of integrated application of compost, lime and phosphorus on selected properties of soil and P use efficiency of maize. The treatments were factorial combinations 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) in randomized complete block design with three replications. The combined analysis of the two season data showed, significant (P<0.01) interaction effects of season with compost and season with P on soil pH; compost with P; and lime with P on apparent P recovery and utilization efficiency; season, lime and P on exchangeable acidity; and interactions of season, compost, lime and phosphorus on the available P. The highest soil pH (6.23) was observed due to compost (5 t ha-1) in the first season (2014) and the highest reduction in exchangeable Al (0.05 cmolc kg-1) was due to lime (3 t ha-1) in the first season (2014). The highest P apparent recovery (6.29%) and utilization efficiencies (169.12 kg kg-1) were observed due to combination of compost (5 t ha-1) with P (20 kg P ha-1). The exchangeable acidity was highly reduced due to combination of lime at 1.5 t ha-1 with P at 40 kg P ha-1 in the first season; while the highest available P (15.04 and 14.65 cmolc kg-1) was observed due to combination of compost at 5 t ha-1, lime at 1.5 t ha-1 and P at 40 and 20 kg P ha-1 in the first season. Therefore, combination of compost with P or combination of compost, lime with P could be helpful treatments in reducing the exchangeable acidity and increase the available P use efficiency, respectively.