Intensification Strategies for Small-Scale Irrigation Systems in Urban Areas: Case Study of Bamako District

Small-scale irrigation in urban and peri-urban areas plays a key role in food security and livelihood improvement in Bamako, Mali. This study evaluates the performance and constraints of 10 irrigated market gardening sites using field surveys, soil and water analyses, and crop water requirement assessments. The objective was to assess the current status of irrigation practices, identify the main agronomic and environmental constraints, and propose feasible strategies for sustainable intensification in these production systems. Results show that soils are predominantly sandy (78–98%) with low organic matter (0–2%), making them poorly fertile and highly water demanding. These soil conditions reduce water retention capacity and increase the need for frequent irrigation, which may further aggravate inefficient water use. Irrigation water quality remains generally acceptable, with no significant heavy metal contamination (<0.01 mg/L), indicating that water sources are suitable for vegetable production under the studied conditions. However, irrigation practices were found to be inefficient, with applied water exceeding crop requirements by 2 to 8 times. Irrigation efficiency is estimated at 40–50%, reflecting substantial water losses and poor control of water application at field level. Correlation analysis indicates that crop yield is more related to water application than to irrigation efficiency, suggesting that farmers tend to compensate for low efficiency by over-applying water. While this practice may help maintain production in the short term, it is neither economically nor environmentally sustainable. Excessive irrigation may also contribute to nutrient leaching and long-term soil degradation.