Effect Of Watering Points On Vegetation And Soil Physio-Chemical Properties And Community Based Water Resource Conservation In Kajiado County, Kenya

Abstract

Water crisis in the Kenyan rangelands threatens the sustainability of pastoral livelihoods. The Water Act of 2002 created the Water Resource Users’ Associations (WRUAs) to enhance water resource conservation and enhance water access at the local level. Yet, environmental degradation has increased in many areas, further exacerbating water crisis and threatening livelihoods. This study therefore assessed community based water resource conservation in the Southern rangelands of Kajiado, Kenya through a survey. Results showed that access to information on water resource management was significantly associated (χ2=0.56, p≤0.05) with membership to the WRUA. The main challenge facing the WRUA was lack of funds (93.2%). Public awareness campaigns aimed at increasing WRUA membership should be done to boost water resource conservation. The government should also increase WRUA funding in order to facilitate its conservation efforts. Water shortage in Kenyan rangelands has also led to introduction of watering points as an intervention measure by government agencies and other stakeholders. This has adversely impacted on vegetation due to increased animal grazing around these watering points. In this study, the effect of watering points on Shannon-Wiener’s diversity index, species richness and Pielou evenness in the southern rangelands were also evaluated. Vegetation sampling was done during both the long rains (April) and the dry season (August). Three watering point types (dam, trough and a seasonal river) were studied using 0.25 m2 quadrats to sample vegetation at intervals of 20 m along 100 m transects. Two-way ANOVA was used to determine if piospheric distance had effect on Shannon-Wiener’s diversity index, species richness and Pielou evenness using GenStat 15th edition. A total of 22 grasses and 29 forbs were recorded in the study area. The most abundant grasses near the watering points were Eragrostis tuneifolia (12.9%) and xiv Cynodon dactylon (10.6%) while the most abundant forbs were Crotolaria brevidens (37.5%). Shannon-Wiener diversity index significantly increased (F=25.07, p=0.001) with distance from the three watering points and was significantly different between them, being higher (F=10.05, p=0.001) at 20m from the river (1.2±0.1) compared to a similar distance from the dam (0.9±0.1) and the trough (0.8±0.2). We recommend reseeding degraded watering points with perennial species tolerant to high intensity utilization. Further, animals should be herded to reduce grazing near the watering points and allow for plant species regeneration. In order to provide more insights to guide future water interventions, we also determined the effect of watering points on soil physio-chemical characteristics. Soil samples were collected within the 0.25m2 plots along the 100 m transects and bulk density, porosity, hydraulic conductivity, moisture content, aggregate stability, soil texture, organic carbon, total nitrogen and pH determined. Data was analysed using GenStat 15th edition. Soil bulk density was significantly different between piospheric distances (F=22.25, P=0.001) and watering points, (F=13.10, P=0.002), being highest at 20 metres from the trough (1.1-1.21gcm-3) relative to a similar distance from the dam (1.01-1.20gcm-3) and the river (1.1-1.17gcm-3). High soil bulk density signified high compaction near the watering points. It is recommended that herding and rest periods be instituted in order to minimize compaction and allow for soil generation near these watering points. Watering points should also be better planned and placed at landscape level to exploit landscape heterogeneity. Key words: Piospheres, Diversity, Soil Bulk density, Rangelands.