Soil acidity is one of the chemical soil degradation problems that affect the productivity of the soil in Ethiopian highlands. The purpose of this research was to study the influence of lime and P fertilizer on the acid properties of soils under the Barley crop grown in the Loya southern region of Ethiopia. A field experiment was conducted at Loya Woreda for three consecutive seasons. The experiment comprised the following treatments; Five levels of Lime (0,58.5,117,175.5, and 234 kg/ha-1) and Four Levels of phosphorous (0,23,46, and 69 kg/ha-1) and was Laid out in a Randomized complete block design with three replications. The pooled mean analysis result showed that above ground, biomass was significantly (p>0.05) influenced by the application of phosphorus fertilizer, lime, and their interaction. The maximum and minimum above-ground biomass is 16840 kg/ha and 9920 kg/ha. They obtained at 46 kg P ha-1 and control treatments, respectively. Amongst the liming treatments, liming at 117kg/ ha gave significantly (P < 0.05) the highest above-ground biomass of barley. Similarly, the grain yield of barley was significantly influenced by applying different phosphorus fertilizers; the highest gain yield was obtained at 46 kg P ha-1. However, grain yield was not significantly affected by applications of different levels of lime but numerically highest grain yield (2320 kg/ha) was obtained at 117kg/ha of lime. In all harvesting seasons, and pooled mean of TSWT did not show significant variation among different levels of phosphorus and lime. Hence, for sustainable and higher productivity, barley production in Loya southern Ethiopia should be 117 kg ha-1lime and46 kg P ha-1. However, the effect of lime application on soil reaction and exchangeable acidity was not properly discussed in this particular study due to a lack of soil laboratory results.