Impacts of watershed management interventions on soil moisture potential, soil texture and soil bulk density in Yezat watershed, upper Blue Nile Basin, Ethiopia

Abstract

ABSTRACT In Ethiopia, watershed management interventions have been implemented since the 1980s to curb land degradation and improve soil moisture potential. Thus, this study was aimed at evaluating the impacts of watershed management interventions on the soil moisture potential, soil texture, and bulk density of the study area. A quasi-experimental research design was employed for this analysis. A total of 99 soil samples were collected for soil moisture, soil texture, and soil bulk density laboratory analysis at a depth of 0–20 cm. Moreover, a one-way ANOVA was used to evaluate the mean variances of soil moisture, soil texture, and bulk density attributes among each treatment group in the study area. Univariate analysis was also applied to evaluate the overall effects by following the General Linear Model (GLM). The results of the study showed that a statistically significant difference (P≤ 0.05) was observed in soil moisture status between the treated (physical and bio-physical) and untreated (controlled) farmlands in each cycle of soil moisture status. At each time of observation, bio-physical types of watershed management interventions had a high moisture status (43.6%), followed by physical types (38.63%) of watershed management interventions, while low amounts of soil moisture (30.16%) were observed in untreated (control) parts of the watershed. The correlation between soil texture and soil moisture content indicates that soil with a high moisture content has a fine soil texture. Whereas soil with a low moisture content has a coarser texture. Both soil moisture and soil bulk density were also significantly affected due to watershed management interventions in the study area (P ≤ 0.05). Therefore, the findings revealed that watershed management increased soil moisture potential and decreased the soil bulk density of the watershed. There is also a strong negative correlation between soil moisture and soil bulk density [r = −0.81, n = 27, p<0.005].