Assessment of the Existing Irrigation Scheduling Practices and Performance of Scheme: Case of Tana‐Beles Sugarcane Irrigation Scheme, Northwestern Ethiopia

The productivity of sugarcanes in the Tana Beles irrigation scheme are significantly constrained by poor irrigation scheduling, improper irrigation water management, and deteriorating irrigation infrastructure. The study aimed to analyze irrigation scheduling practices and assess key performance indicators of the scheme. Soil physical properties, such as texture, field capacity (FC), and permanent wilting point (PWP), were analyzed in the laboratory. Flow along the canal and field inlet was measured using V‐notch weirs with a maximum and minimum discharge capacity of 13.2 and of 0.18 L s ⁻¹ , respectively. Irrigation intervals for each sugarcane growth stage were estimated using CROPWAT 8 and compared with the existing practices. Application, conveyance, and storage efficiencies, percolation losses, water surface elevation ratio (WSER), infrastructure effectiveness, irrigated‐area sustainability, and infrastructure condition were evaluated. The existing and calculated irrigation intervals are 8 and 5 days for the germination stage, 8 and 9 days for the initial stage, 15 and 10 days for the development stage, 20 and 13 days for the mid stage, and 20 and 22 days for the late stage, respectively. The mean application efficiency, storage efficiency, and percolation ratio (PR) were 71.7%, 89.5%, and 28.3%, while the average conveyance efficiencies for the tertiary and field canals were 79.1% and 70.2%, respectively. In terms of physical condition and functionality of infrastructure, the mean values for WSER, infrastructure effectiveness, and irrigated area sustainability were 74.0%, 72.7%, and 89.8%, respectively. Seepage and sedimentation affected about 76.9% of the unlined canal length, while 78.6% of hand‐lifted gates had deteriorated. Generally, improvements in irrigation scheduling are needed to better align intervals with crop water requirements. The canal maintenance should be strengthened to reduce seepage and sedimentation and rehabilitation of deteriorated gates is also essential to ensure reliable operation. Future work should prioritize optimizing irrigation intervals by integrating real‐time soil moisture monitoring and localized climate projections, and evaluating the efficiency of main and secondary canals (SCs) to strengthen the long‐term functionality of the scheme.