Farmers' practices in on-farm irrigation management in the Gezira Scheme, Central Sudan

摘要

After a general introduction and descriptions of how irrigation water is carried to the fields, we review problems with the management of Nile water for irrigation in the Gezira Scheme, Central Sudan. Subsequently the methodologies used in an on-farm experiment are described. From the results of a questionnaire, the farmers' present irrigation practices are discussed. Field data show that unattended, day and night, continuous flow irrigation of sorghum (dura) and groundnuts uses more water, and particularly so in drier years, than attended daytime watering (and night-time storage). This is mainly due to greater evaporation from water standing on the surface, because percolation is negligible. In this case study, in the order of 20-40% of used water was wasted on-farm. It is deduced that farmers evolved their present practice of watering groundnuts and sorghum out of the sheer necessity of engaging sharecroppers who themselves have to leave irrigation unattended because of their own need for additional off-farm income. Finally, some conclusions and recommendations are derived for a dialogue between authorities and tenants on more efficient water use. The new situation of tenants as "cost-sharing partners" could lead to better watering practices if they would pay for the water they use by volume and if the authorities would carry out maintenance to the full satisfaction of the tenants.