In order to reduce the high energy consumption of center-pivot irrigation systems, low pressure sprinkers are becoming more popular. Due to lower wetting diameter of these types of sprinklers they have high application rates which are more than infiltration capacity of most agricultural soils. This will lead to excessive runoff in sloping fields and considerable reduction in water application efficiency of this irrigation system. The problem is more sever near the end of lateral. A research study was carried out in Hamadan, Iran to assess the problem. In this study two types of parallel booms were used. one was 8 m long with 2 spray heads and the other was 13 m long with 3 spray heads. the booms were oriented perpendicular to the lateral. Three experimental plots with slopes of 1.07, 1.48 and 1.87 percent were used to quantify the amount of runoff. The results of this study showed that runoff under long boom system was reduced 73.1% and 69.1% at 20% and 40% speed, respectively when compared to single spray head system. Also, the short boom system reduced the amount of runoff by 5 1.9% and 45.8% at the mentioned operational speeds, when compared to single spray head system. The accuracy of these data was supported by the results obtained from the potential plot.
)