Intensifying agriculture in Africa has been shown to degrade water quality in rivers and lakes. In consequence, pollution and eutrophication can pose a threat to local water resources. Water pollution is caused by increased deforestation and severe erosion rates, as land degradation leads to over-utilization of inorganic fertilizers.
Unfortunately, there is a lack of attention towards environmental issues during the intensification of agriculture. Source-based intervention mechanisms are needed to reduce pollution of water resources. Strategies for soil erosion and nutrition management should be put in place to alleviate the challenge. To develop efficient strategies against pollution, a thorough understanding of the situation is crucial. This can be provided by research on pollution sources.
In their work, which is highlighted on the June cover of CLEAN – Soil, Air, Water, a group of researchers in Ethiopia with a focus on hydrology and water resource engineering analyzes non-point source pollution of an agricultural watershed near Lake Tana. The phosphorous concentration in groundwater is measured in the Awramba watershed and reasons for increased phosphorous content are explored. Mamaru A. Moges and colleagues found that periodically saturated and reduced bottomlands are a main source of phosphorous, whereas mid-slope maize fields only contribute to pollution in high-flow events. These results suggest that converting bottomlands to buffer zones will prevent further pollution and help to preserve Laka Tana as a valuable water resource in Ethiopia.