The conventional surface irrigation systems, border, level basin and furrow bed, are inherently inefficient in Pakistan,
while the suboptimal field sizes (length and width) are considered as one of the main reasons of poor performance.
Addressing these issues, the three surface irrigation systems were evaluated on thirteen fields under routine farmer
management in Pakistan. Irrigation performance including application efficiency (AE), Potential Application Efficiency
(PAE), Adequacy (AD) and distribution uniformity (DU), of 17 irrigation events were evaluated and further potential
for improvement by optimising field sizes were identified using surface irrigation evaluation Model WinSRFR 4.1.3.
The study revealed poor irrigation efficiencies, AElq (41% to 82%), PAEmin (43% to 95%), ADlq (1.16 to 2.29)
and DUlq (80% to 99%), on farms. The average AElq on farm was in the order of; level basin (58%) < border
(65%) <furrow bed (68%). Simulation modelling indicated that there is further potential to increase average PAE
up-to 94%, 87% and 96% for level basin, border and furrow bed irrigated fields respectively, by optimising field
length and width. The analysis demonstrated increased understanding of the interactions of field sizes and irrigation
efficiencies, which may support irrigators’ decision making for enhancing irrigation performance at no significant
cost to infrastructure, machinery or labour.