SOIL ACIDITY STATUS AND DETERMINATION OF LIME REQUIREMENTS UNDER DIFFERENT LAND USES: THE CASE OF KOFELE DISTRICT, WEST ARSI ZONE, OROMIA, ETHIOPIA

ABSTRACT   Soil acidity is a serious problem to agricultural output in Ethiopia's highlands, particularly in Kofele District, West Arsi Zone, Oromia Region. This study was conducted to assess soil acidity status and determine lime requirement under different land uses. Three kebeles, Guchi, Wolabara, and Wamanye Abosa, were chosen randomly from a group of twelve identified as potentially acidic by preliminary surveys. A total of 42 composite soil samples were collected from cultivated and grazing lands across the kebeles, and 42 undisturbed samples were taken using a core sampler for bulk density analysis. Soil samples were analyzed at Kulumsa Soil and Plant Analysis Laboratory for physical and chemical parameters such a soil texture, moisture content, bulky density, electric conductivity, pH, organic carbon, organic matter, available phosphorus, total nitrogen, exchangeable acidity and cation exchange capacity. The results revealed that the soils in the study area are highly acidic. The average pH of cultivated land was 4.44, while the average pH of grazing land was somewhat higher, at 4.76.This results are classified under strongly acid (pH 4.1–5.5). Lime need analysis utilizing the Shoemaker-McLean-Pratt (SMP) buffer method revealed that all kebeles require liming to achieve a soil pH target of 6.0. The average lime requirement for cultivated land and grazing land across the study area was calculated at 3.78 t/ha and 3.1t/ha respectively, confirming that soil acidity is a uniform and common problem in the district. These results highlight in order to improve the productivity of the soil and restore soil health by applying agricultural lime as part of a coordinated soil management approach. Farmers, development agents, and policymakers can use the study as a guide when creating practical strategies to reduce soil acidity in Kofele district and similar agro-ecological zones  4