Inmpact of Land use and management practices on Chemical properties of some soils of Bako area, Western Ethiopia.

Information on the effect of land use and management practices on soil chemical properties in the country, particularly the Bako area (in western Oromia), is generally very little. Therefore, the influence of three different land-use systems (farmer's field, research field and virgin land) on relevant chemical properties of soils in Bako area was investigated through laboratory analysis of soil samples collected from soil profiles representing different land-use systems. The results revealed that the soil reaction (pH in H2O) of the top soil was strongly, moderately and slightly acidic in the research filed, farmer's field and virgin land, respectively. The lowest values of organic carbon (1.24%) and total N (0.08%) were observed in the top soil of the research field whilst the highest (5.90 and 0.33%, respectively) were found I the top soil of the virgin land. Considering the top soil, the lowest CEC (11.00 cmolc kg-1), exchangeable Ca (2.30 cmolc kg-1), exchangeable Mg (1.08 cmolc kg-1) and base saturation (35%) were observed on the research field whereas the highest values of 36.00 cmolc kg-1, 16.41 cmolc kg-1, 4.50 cmolc kg-1 and 62%, respectively, were recorded on t he virgin land Exchangeable K, CEC and ECEC also followed similar trend with the above parameters. On the contrary, the contents ob both total exchangeable acidity and exchangeable all were highest in the research field. The findings demonstrated that land use and management practices have markedly influenced all of the soil chemical properties studied. In summary, the values of all soil chemical parameters studied except that of exchangeable Al and available P decreased in the research field as compared to their respective values in the other two land-use types due to intensive mechanized cultivation and continuous use of inorganic fertilizers for over three decades. Hence, although these soil test results need to be verified by plant tissue tests in order to draw firm conclusion, the results of the present study indicate that frequent monitoring and proper management of some soil chemical properties deserve special attention for he sustainable productivity of the soils of Bako under different management practices. Reducing the intensity of mechanized farming and adopting integrated soil fertility management may reverse the present situation and replenish the degraded chemical properties of the soils in the fields under the research field.