Effects of integrated land management technology adoptions on soil properties, evidence from the Goyrie watershed, Southern Ethiopia

Since 2008, integrated land management technology (ILMT) adoptions have been applied to minimize soil depletion and improve soil properties in the Ethiopian highlands, including the study watershed. However, the effect of combined technologies on soil properties was not investigated through standard laboratory procedures in the Goyrie watershed. Thus, the purpose of this study was to evaluate the effects of ILMTs on selected soil properties in the Goyrie Watershed of southern Ethiopia. A total of 27 composite soil samples (three replications, three farmlands per management category, and three slope positions) were randomly collected from the top soils at a depth of 0-20 cm. A one-way analysis of variance (ANOVA) was used to examine mean soil property variation between treated and non-treated farmlands and slope positions, while a two-way ANOVA was used to examine the interaction effects. The result showed that farmlands treated with soil bunds and desho grasses had significantly higher mean clay content (50%), total porosity (59.6%), soil pH (6.7%), soil organic carbon (SOC) (2,49%), soil organic matter (SOM) (4.29%), total nitrogen (TN) (.23%), available phosphorus (Av. P) (7.83%), cation exchange capacity (40.11%), and exchangeable basic captions compared to farmland treated with only single technologies and without conserved farmlands. Non-treated farmlands had higher sand (32.84%) and bulk density (1.38%) contents. Whereas lower landscape sites had higher mean value of clay (29%), K+ (.49%), Ca2+ (8.93%), and Mg2+ (2.23%) content than the middle and upper slope sites. Clay content, soil pH, SOC and SOM contents were statistically and significantly influenced by the interaction effects of management technologies and slope gradient. Overall, the three PCAs' contributed to 71.52% of the total variance. Adoption of soil bunds with multipurpose fodder species is a promising approach for improving soil properties and should be applied to the non-treated farmlands of the Goyrie Watershed.