Abstract:
Most of Ethiopian highlands are affected by severe top soil loss caused by soil erosion which
in turn resulted in the deterioration of soil properties. To reverse the situation, soil and water
conservation measures were widely practiced in these highlands. However, the effect of these
measures on soil properties is not well-studied and documented in the study area. Hence, this
study was conducted to evaluate the effects of soil and water conservation measures and slope
gradient on selected soil physico-chemical properties at Dawnt watershed, North Western
Ethiopia. Treatments were combinations of four Soil and Water Conservation measures (nonconserved,
stone-faced
soil
bund,
stone-faced
soil
bund with kidan grass and soil bund) and
three slope gradients (upper, middle and lower) laid out in a Randomized Complete Block
Design replicated three times. Disturbed and undisturbed soil samples were collected from
surface (0-20 cm) soil depth. Soil physico-chemical properties were determined following
standard laboratory procedures and the data were subjected to ANOVA using SAS software
9.1. Significant different means were separated using Least Significant Difference (LSD) at
5% significance level. Sand, bulk density, moisture, particle density, porosity, pH, organic
carbon, CEC, total nitrogen and available phosphorus were significantly (P<0.05) affected
by conservation measures, slope gradient and interaction. High organic carbon (2.44%),
CEC (45cmol (+) kg
-1
) and moisture (19.55%) were obtained from SFSBG and high available
phosphorus (7.83ppm) from SB while lower bulk density (1.13gm/cm
xvii
3
) from SFSBG. No
significant difference among conservation measures in total nitrogen except from the nonconserved
field. In addition, higher clay (41.67%) and moisture (19.81%) and lower bulk
density (1.14g/cm
3
) were obtained from lower slope. Higher pH (6.75) and organic carbon
(2.89%) were recorded at lower slope under stone-faced soil bund with kidan grass and lower
(6.03 and 1.02%) at upper slope with non-conserved. Soil chemical properties, except
available potassium showed an increasing trend down the slope. In general, even though soil
properties were improved due to conservation, some are by far below critical levels. Hence,
improving organic matter by integrating conservation measures with multipurpose plants and
soil properties through organic amendments should be high priority.
