Some Physico-Chemical and Mechanical Properties and Workability of Bilecik Şeyh Edebali University Campus Soils

Abstract

In this study, some physico-chemical and mechanical properties and appropriate moisture levels for workability of soil series in Bilecik Şeyh Edebali University Campus area in Turkey were determined. Soil samples were taken from 0 - 20 cm depth of 20 different points in Gülümbe and Aşağıköy series. Soils in the Gülümbe were clay (C) and clay loam (CL) in texture with a mean bulk density of 1.05 g cm-3, saturated hydraulic conductivity of 0.66 cm h-1, slightly alkaline (pH=7.74), medium soil organic matter (SOM) (2.01%), high lime (17.08%), insufficient available phosphorus (1.92 kg P2O5 da-1), sufficient available potassium (88.54 kg K2O da-1), cation exchange capacity (CEC) of 37.71 cmol kg-1, insufficient available Fe (2.35 mg kg-1 ) and available Mn (5.18 mg kg-1 ), sufficient available Zn (1.81 mg kg-1) and available Cu (1.00 mg kg-1) contents. Soils in the Aşağıköy were loamy (L) and sand-clayloam (SCL) in texture with a bulk density of 1.31 g cm-3, saturated hydraulic conductivity of 2.32 cm h1, slightly alkaline (pH=7.74), low organic matter (1.81%), medium lime (6.75%), high available phosphorus (18.76 kg P2O5 da-1 ), sufficient available potassium (133.94 kg K2O da-1), CEC of 25.26 cmol kg-1, sufficient available Fe (5.67 mg kg-1) and available Cu (2.57 mg kg-1), insufficient available Mn (3.21 mg kg-1) and available Zn (0.66 mg kg-1) contents. While the highest liquid limit (LL) (68.17%) and plastic limit (PL) (31.49%) values were determined in Gülümbe series with the highest clay content and the lowest LL (46.50%) and PL (24.80%) values were in Aşağıköy series with the lowest clay content. Plasticity index (PI) of the soils in Gülümbe and Aşağıköy series respectively varied between 32.73 - 40.26% with a mean of 36.17% and between 21.70 - 28.0% with a mean of 24.73%. Based on LL and PI values, Gülümbe soils were classified as “highly plastic inorganic clays” and Aşağıköy soils were classified as “moderately plastic inorganic clays”. LL values of the soils had significant correlations with clay (0.88**), sand (-0.71*), PL (0.75**), PI (0.89**), consistency index (0.57*), SOM (0.62*), CEC (0.75**) and available K2O (0.54*). The upper and lower moisture limits for optimum tillage were recommended as 29.15 - 23.50% for Gülümbe series and as 24.95 - 21.24% for Aşağıköy series. It was concluded that campus soils could be cultivated at field capacity without any structural deformations because of the consistency index values were between 0.75 - 1.00.