Abstract:
Traditional irrigation schemes constitute about 40% of the total irrigated land in Ethiopia. Despite this, the sector has been overlooked and not supported by improved water management technologies. A survey conducted on one of the schemes, Godino, indicated that farmers apply the same amount of water regardless of crop type and growth stage. In view of this, an experiment was established at the Debre-Zeit Research Centre in Ethiopia with the objective of comparing the performance of two traditional irrigation management practices to two scientific scheduling methods namely an Irrigation Calendar generated with the Soil Water Balance (SWB) model and a neutron probe (NP) based scheduling method. The four irrigation regimes were applied to furrow irrigated potatoes. Plant sampling for dry mass determination was undertaken on a weekly basis. Results of leaf, canopy and total dry matter, as well as fresh tuber yields, indicated that the NP and SWB schedules were superior to the traditional scheduling methods. Leaf dry matter was the most responsive parameter to irrigation treatments. The overall results revealed that traditional irrigation practices did not meet the full potato crop water requirements to ensure acceptable yield, which emphasized the need for introducing better and more efficient practices. Since the best performing treatment, NP, is capital and skills intensive, site specific SWB calendars, which performed similarly to NP and are simpler to use, are to be recommended for farmers at the Godino scheme.
