Abstract:
The nutrient supplying power of a soil depends on dissociation of the nutrients from the exchange
site, which is in turn dependent on the degree of saturation of the nutrients on the exchange site,
type of clay and complementary ion effect. The study was conducted in Kake kebele, Dalle
Wabera District, Kellem Wollega Zone, South West Ethiopia. The aim of the study was to assess
macro and micro nutrient status of soil in different land uses (Cultivated, Fallow and Forest lands)
on the magnitudes and directions of major soil fertility parameters and among land use types and
soil depths. Site selection, Sample collection, Sample preparation and Laboratory analysis are the
major methods of sampling technics. The results showed that the highest (5.56) and the lowest
(5.27) soil pH-H2O values were recorded under the forest and the fallow lands, respectively.
Electrical conductivity (EC) of soils was not significantly affected by land use types and by the
soil depth. Considering the main effects of land use types, the highest (1.02 dS/m) EC was
recorded under the cultivated and fallow lands whereas the lowest (0.96 dS/m) EC value was
obtained under forest land. The mean values of exchangeable calcium (Ca2+) under cultivated land,
the fallow and the forest lands were 2.20, 4.20 and 3.22 cmol(+) /kg, respectively. The contents
of available micronutrients (Fe, Mn, Zn and Cu) under the different land use types were
significantly different (P ≤ 0.01) and Cu showed reduction from the cultivated land to forest land
(2.91, 2.77 and 2.68 mg/kg) respectively. The results observed in this study revealed that the
average mean values of available Fe and Mn were in the adequate range for the production of most
crop plants. Available Fe under land uses and soil depths was positive and significantly correlated
with organic carbon (r = 0.373). The manner in which soils are managed has a major impact on
agricultural productivity and its sustainability. The contents of exchangeable bases will be reduced
because of leaching by erosion, removal of plant residue and burned for energy consumption and
will be used as food for animals. Therefore, to increase the pH and exchangeable bases lime should
be added and to increase the availa ble phosphorus, DAP should be added to the soil of the study
area
