Abstract:
Use of emerging technologies and developed models are now replacing the highly expensive,
unsafe, time consuming and the outdated wet chemistry method of analyzing soils. In relation
to this, pedotransfer functions (PTFs) have recently become a popular topic in soil science to
predict physical and/or chemical soil properties. In this study, an attempt was made to relate
the measured values with pedotransfer function models estimated selected soil water values
across different soil types in the command area of Megech Irrigation development Project,
East Dembiya district, northwestern Amhara. In addition, a change in selected soil properties
with respect to changing land use types and soil types were also evaluated. For this, about 30
disturbed and 30 undisturbed soil samples were collected from two soil depths (0-25cm and
25-50cm), and three land use types (eucalyptus plantation, grazing land, and cultivated
lands). To capture the influence of soil type differences on the status of identified soil
properties, samples were collected from cultivated lands represented by three dominant soil
types in the command area namely Vertisols, Luvisols, and Fluvisols. Soil analysis activities
were performed in Gondar and Bahir Dar soil laboratories following the routinely used
laboratory procedures. The soil analysis results indicated that the studied land use types have
clay textural classes; neutral to moderately alkaline pH (6.7-7.66) and low OC values. The
soil BD value was different for different soil types studied and ranged from the lowest 1.16
gm/cm
3
for Vertisols to the highest 1.44 gm/cm
3
for Fluvisols. Similar to land use types, the
OC content of studied soils is generally found in the low range (0.5-1.5%). This can be
considered as an indicator of the poor fertility level of the study area soils. From different
pedo-transfer function models tested, model 6 was found to be a better estimator of FC and
PWP values for the identified soil types in the study area. Therefore, for the study area soils,
use of model 6 to estimate FC and PWP values, closer supervision of soil pH when the
irrigation project becomes operational and addition of organic fertilizers are generally
recommended
