ASSESSMENT OF SOIL QUALITY UNDER DIFFERENT GRAZING INTENSITIES IN THE RIMA RIVER FLOODPLAIN, KWARE LOCAL GOVERNMENT AREA OF SOKOTO STATE, NIGERIA.

ENIOLORUNDA Nathaniel Bayode

The Rima River floodplain is reportedly overgrazed but effects of grazing on soil quality is yet to be investigated. Thus, the study examined soil quality across grazing intensities. Three juxtaposed grazing intensities namely Dense Grassland (Low), Grassy Fallow (Medium) and Grazed Open Grassland (High) were identified based on an existing Land-Use/Land-Cover (LULC) map. From each treatment, soil sampling was carried out at 15 randomly selected 10m *10m quadrats. Also, 4 subsamples were augered to 0-30cm depth at the corners of the quadrat after which the subsamples were bulked and homogenized. Four bulk density (δB) subsamples were also taken at the sides of the quadrat using a core sampler, the readings of which were averaged for the quadrat after the laboratory test. Samples were analyzed using standard laboratory procedures. Descriptive statistics of soil properties were calculated, while ANOVA was used to determine grazing effect on soil quality. Duncan Multiple Range Test (DMRT) was used for a post-hoc test on the treatments for each of the soil properties. Results showed that Soil Organic Carbon (SOC), Total Nitrogen (TN), Available Phosphorous (P), Potassium (K), Cation Exchange Capacity (CEC) and δB significantly differed (p<0.05) across grazing intensities with exception of pH. All properties decreased with increasing grazing intensity except δB which increased with increasing grazing intensity. pH did not exhibit a predictable pattern across treatments. The study concluded that grazing negatively affected the soil quality of the Rima river floodplain. Establishment of grazing areas within the floodplain was recommended for sustainable soil management.

Key words: Floodplain, Grazing, Rima, Soil quality, Sokoto.