Abstract:
In most developing countries, including Ethiopia, the amount, rate and intensity of land use
changes are very high. This study was conducted in Mere watershed; northwest Ethiopia with
the objective of analysing land use land cover change and investigate the effect of different
land use types and soil depth on soil properties. Land cover maps of 1990 and 2018 were
interprated and analyzed within GIS to quantify the land cover change in the study area. Four
major land use types: natural forest, grazing land, cultivated land and plantation forest lands
were selected. While undisturbed core and disturbed composite soil sample were collected
with three replications for each land use types at two depths (0-20 cm and 20-40 cm).
Standard soil analytical procedures were followed in carrying out soil analysis. The soil
physicochemical properties were analyzed at Amhara Design and Supervision Works
Enterprise, Bahir Dar. The statistical results revealed that variations due to land use types
and soil depth. sand, clay, bulk density, pH, organic matter, total nitrogen, available
phosphorus, cation exchange capacity and exchangeable Ca, K, and Na were significantly (p
< 0.05 and/or p < 0.01) different. In contrast, silt, carbon to nitrogen ratio and exchangeable
Mg were not significantly (p > 0.05) affected. The highest value of all soil chemical
properties except exchangeable Na and C: N ratio were recorded under natural forest and the
lowest value except CEC, Na and C: N ratio was found under plantation forest. With soil
depth, the higher mean value of organic matter, total Nitrogen and cation exchange capacity
were recorded in the 0-20 cm than 20-40 cm depth and the higher mean value of pH and
exchangeable Na was recorded in the 20-40 cm than 0-20 cm depth. Texture, bulk density,
available Phosphorus, C: N, exchangeable bases (Ca, Mg and K) were not significantly (p >
0.05) affected by soil depth. The changes of natural forest to other land use types were one of
the impacts of soil fertility that contributed to low agricultural productivity. Therefore, the
study is suggesting the need for intervention to sustain and optimize the soil quality.
Key Words: cultivated land, natural forest, grazing land, Soil depth, Soil physico-chemical
properties
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Chapter 1. INTRODUCTION
1.1. Background and Justification
In most developing countries, including Ethiopia, the amount, rate and intensity of land use
changes are very high. The out come of these changes are deterioration of soil physico
chemical properties (Rao and Pant, 2001). Ethiopia is gifted with potential r