Distribution of Irrigation Water from a Low Pressure, Lateral-Moving Irrigation System

FUNDAMENTAL considerations for irrigation water applications from lateral-moving irrigation systems are presented. The application dynamics are discussed relative to low-pressure, lateral-move irrigation machines. A prototype low pressure, lateral-move irrigation system was evaluated by testing several applicator systems for low volume, frequent irrigations. Results indicated that static uniformity coefficient exceeded 0.98. However, the dynamic uniformity coefficient was about 0.90. Pressurization requirements can be reduced to less than 200 kPa (possibly as low as 100 kPa) with little reduction in uniformity. The spray losses (both drift and evaporation) from the low pressure, overhead spray systems were about 10%. System alignment and, particularly, system speed control appear important to achieving uniform applications with low-pressure, lateral-moving systems. Additional research on speed control technology appears desirable.