Description
Cactus Opuntia stricta primarily invades arid and semi-arid lands (ASALs), which form more than 80% of Kenya’s landmass. The ability of the plant to tolerate poor soils and accumulate biomass under low precipitation has resulted in studies into its potential use by pastoral communities for biofuel and livestock feed. However, few studies have assessed the below-ground benefits associated with cactus under rangeland conditions. In this study, we evaluated the root contributions of the invasives cactus Opuntia stricta under rangeland conditions in Laikipia, Kenya. The experiment was laid out in a randomized complete block design with ten (10) replicates, each measuring 30 × 30 m. Each block was further subdivided into three plots of 10 x 30m Three clusters were randomly selected from each plot for roots and soil samples starting from the center of the cluster (C) to the outside in a gradient of three radii, R1, R2 and R3. Data was collected for root (dry root biomass, % carbon and % nitrogen) and soil (pH, bulk density, % moisture and % nitrogen) characteristics. Significant differences in total root mass, root carbon, and root nitrogen were observed under varying cluster gradients. Root mass ranged from 4527.0 to 9242.0 kg/ha for the outermost radius (R3) and the cluster’s center, respectively. Similarly, except for the soil nitrogen, statistical differences were observed for soil bulk density, percent soil moisture and percent nitrogen along the different cluster gradients. The soil bulk density ranged from 1.2±0.02 (center) to 1.5±0.01 g cm3 (radius 2). Findings from this study demonstrate the important contribution of the invasive cactus species in sustaining the ecological functions of rangeland soils such as those found in Laikipia, Kenya.
Citation
Oduor, K. T.; Dubeux, Jose C. B.; Owino, W. O.; Ruiz-Moreno, M.; Queiroz, L. M. D.; and Bretas, I. L., "Below Ground Benefits of Cactus Opuntia stricta Under Rangeland Conditions in Laikipia, Kenya" (2024). IGC Proceedings (1993-2023). 7.
https://uknowledge.uky.edu/igc/XXV_IGC_2023/Policies/7
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Below Ground Benefits of Cactus Opuntia stricta Under Rangeland Conditions in Laikipia, Kenya
Cactus Opuntia stricta primarily invades arid and semi-arid lands (ASALs), which form more than 80% of Kenya’s landmass. The ability of the plant to tolerate poor soils and accumulate biomass under low precipitation has resulted in studies into its potential use by pastoral communities for biofuel and livestock feed. However, few studies have assessed the below-ground benefits associated with cactus under rangeland conditions. In this study, we evaluated the root contributions of the invasives cactus Opuntia stricta under rangeland conditions in Laikipia, Kenya. The experiment was laid out in a randomized complete block design with ten (10) replicates, each measuring 30 × 30 m. Each block was further subdivided into three plots of 10 x 30m Three clusters were randomly selected from each plot for roots and soil samples starting from the center of the cluster (C) to the outside in a gradient of three radii, R1, R2 and R3. Data was collected for root (dry root biomass, % carbon and % nitrogen) and soil (pH, bulk density, % moisture and % nitrogen) characteristics. Significant differences in total root mass, root carbon, and root nitrogen were observed under varying cluster gradients. Root mass ranged from 4527.0 to 9242.0 kg/ha for the outermost radius (R3) and the cluster’s center, respectively. Similarly, except for the soil nitrogen, statistical differences were observed for soil bulk density, percent soil moisture and percent nitrogen along the different cluster gradients. The soil bulk density ranged from 1.2±0.02 (center) to 1.5±0.01 g cm3 (radius 2). Findings from this study demonstrate the important contribution of the invasive cactus species in sustaining the ecological functions of rangeland soils such as those found in Laikipia, Kenya.