Tillage operation aims to create a favorable environment for seed germination of agricultural crop production practices. Physio-mechanical properties of soil directly affecting soil behaviors and determinants in initial conditions affecting soil failure. An absence in understanding how soil physio-mechanical properties affect agrotechnical operations at different tillage depths, especially in study area, and lacks insights into their associations and practical implications for optimizing tillage and soil health. This study presents an experimental investigation of the physio-mechanical properties of agricultural soil in Bukito Kebele, Loka Abaya woreda of Sidama Regional state, Ethiopia. The objective was to identify these properties under varying agro-technical soil depth conditions. Randomized Complete Block Design (RCBD) field experimental design was spotted to take soil samples using appropriate sample equipment and further lab analysis was conducted. Loka Abaya farm soil is loam, offering balanced texture for drainage, water retention, and nutrient availability. Moisture content reaches a maximum of 24.36%, with a linear relationship between soil depth and moisture content. The Atterberg limits of the soil (LL: 37.5-40%, PL: 25-27.5%, PI: 10-15%) indicate low plasticity and low clay content, consistent with loamy or silty soils. The results also show that soil cohesion is low in the topsoil (surface layers) but increases significantly at depths of 10-15 cm. Soil resistance decreases with depth due to reduced compaction and increased pore space in subsurface layers. Bulk density peaks at 1.28 g/cm3 at 10 cm depth due to high organic matter decomposition, then decreases to 1.20 g/cm3 at 15-20 cm, likely from reduced organic matter and root activity in subsurface layers. Correlations analysis reveals that soil moisture strongly increases with depth (r = 0.99, p < 0.01), indicating that deeper tillage may be necessary in arid regions to access moist soil layers. Sandy soils, which show a strong link between plastic limit and sand percentage (r = 0.97, p < 0.01), require adequate moisture during tillage to prevent erosion. Moist, cohesive soils are less compacted (r = - 0.92, p < 0.05) and easier to till, while cohesive soils resist penetration (r = - 0.90, p < 0.05), highlighting the need for efficient tillage equipment to minimize energy use. Overall, soil moisture, texture, and cohesion are critical factors for optimizing tillage practices and enhancing soil health. The study's site-specific nature limits its broader applicability, its focus on physical properties few mechanical property, overviews chemical and biological aspects, and further research is required to understand the long-term impacts of tillage on soil structure and productivity.

Exploring the relationship between the physio-mechanical properties of the loess-paleosol sequences and the paleoclimate can help provide essential references for engineering construction in the Chinese Loess Plateau, revealing the vital application value of Quaternary climate research. Continuous loess-paleosol sequence in the central Loess Plateau was selected to determine its physio-mechanical and chemical characteristics. The main results show: (1) During the interglacial period, the East Asian summer monsoon intensified, and the cementation of clay minerals made the soil structure dense under more precipitation, increasing soil cohesion. During the glacial period, the East Asian winter monsoon was stronger, and the loess's unstable microstructure was formed under the weak pedogenesis, increasing the compressibility and collapsibility. (2) The alternation of cold-dry/ warm-humid climate in the Quaternary is the fundamental reason for the differences in physio-mechanical properties and structural strength between loess and paleosol; pedogenesis plays a direct decisive role. The impact of compaction after burial on the physio-mechanical properties of loess-paleosol sequences is less than that of pedogenesis. (3) Precipitation plays a dominant role in the shear strength and compressibility of loesspaleosol sequences, while precipitation and temperature jointly affect the collapsibility. A quantitative relationship between paleoclimate and physio-mechanical properties was established.