Strategies to Improve the Irrigation Efficiency of Raised Beds on Small Farms

The suboptimal irrigation management on small raised beds farms in the Indus Basin is considered to reduce irrigation efficiency and exacerbates waterlogging and salinity. Addressing this issue, farmer managed irrigations on commonly used Narrow Bed (NB) with furrow spacings 66 cm and newly introduced Wide Bed (WB) with furrow spacing 130 cm on sandy clay loam, were investigated using the irrigation modelling software, WinSRFR, to explore irrigation management strategies for improving irrigation eficiency. The study revealed existing average application efficiency of low quarter (AE lq) 71%, 87%, distribution uniformity of low quarter (DU lq) 70%, 80% and adequacy of low quarter (AD lq) 100 %, 90% for NB and WB, respectively. Majority (67%) of WB irrigations monitored were under irrigated while large number (50%) of NB irrigation were over irrigated. Simulation modelling showed that achievement of above 90% Potential Application Efficiency (PAE) is possible by improving operation (inflow rate and time to irrigation cut-off) and field design (field length and width/number of furrows per set). This work raised the prospects of improved irrigation efficiency of raised beds in Indus Basin, which may be possible without incurring any costs associated with altered infrastructure, new or modified machinery, or increased labour.