Spatial stoichiometric distribution trend of various nutrients around Lake Chamo basin, Ethiopian Rift Valley region in relation to wetland conversion to farm and grazing land sites

Lake Chamo riparian wetland is currently subjected to intensive farmland expansion and over grazing more than previously experienced. These coupled threats are escalating primarily riparian vegetation deforestation and resulted in pronounced nutrient imbalance and shrinking wetland size. The current study investigated spatial soil stoichiometric distribution of C, N, P, S, K and Ca in wetland, farm and grazing land around Chamo Lake riparian wetland, Ethiopian Rift valley. Farm and grazing lands are included as a study site because they were identified part of riparian wetland previously. The results showed high total nitrogen, sulfur, calcium and potassium concentrations in farmland. Grazing land showed high total phosphorus but soil organic carbon. In farmland, available phosphorus was revealed low that justify phosphorus scarcity as a result of crop harvesting for animal feed. The N: P exhibited low in wetland site that implies the effect of crop cultivation and livestock production in the surrounding catchment that increases N input in the wetland site. Soil organic carbon, total nitrogen and potassium were positively correlated with moisture content. Soil organic carbon, potassium, C: N, N: P and C: K was negatively correlated with pH. Total nitrogen, phosphorus, sulfur, potassium, calcium and available nitrogen were related positively with clay contents. We recommended that conservation activities such as participatory wetland management and promoting none agricultural economy to the unemployed youths and creating wetland reserved areas as a buffer zone of the study area could enhance the rehabilitation of the degradation wetland in this study area.