Effect of piospheres on physio-chemical soil properties in the Southern Rangelands of Kenya

Abstract

Abstract Introduction Water-based interventions haphazardly introduced in the drylands of Kenya have led to the introduction of piospheres used as concentration mounts. Not much is known about the effect of these piospheres on soil physio-chemical properties, especially in the Kenyan rangelands where the government and other development agencies have created piospheres aimed at curbing water shortages and sustaining livestock production. The study assessed the effect of piospheres on soil physio-chemical characteristics in the southern rangelands of Kajiado, Kenya, in order to provide evidence-based insights that will be useful in guiding future water interventions. Methods Soil samples were collected within 0.25-m2 plots at 20-m intervals along 100-m transects from three piospheres (a dam, a trough, and a seasonal river). Two-way ANOVA was used to determine if there were significant differences in soil parameters between piospheric distances. Results Soil bulk density significantly different between piospheric distances (F = 22.25, P = 0.001) and piospheres (F = 13.10, P = 0.002), being highest at 20 m from the trough (1.1–1.21 gcm−3) relative to a similar distance from the dam (1.01–1.20 gcm−3) and the river (1.1–1.17 gcm−3). On the other hand, mean soil aggregate stability significantly increased (F = 66.89, P = 0.001) with piospheric distance, being lowest at 20 m from the trough (43.9–46.2%), the dam (43.1–48.9%), and the river (46.6–47.5%). Conclusions High soil bulk density and consequent low soil porosity, hydraulic conductivity, and moisture content demonstrated that grazing was high near the piospheres. It is recommended that livestock should be herded away from the piospheres after drinking water to ensure that grazing livestock spend less time near the piospheres if reduced soil compaction is to be realized. Piospheres should also be better planned and placed at landscape level to exploit landscape heterogeneity.

Keywords

• Piospheres
• Grazing pressure
• Bulk density
• Hydraulic conductivity
• Rangelands