Low Energy Rotary Nozzle: An Energy and Water Saving Device for Field Crop Irrigation

Pressurized irrigation technologies of course have the potential to raise the productivity of land and water; but, these technologies could not popularize among the smallholders who own millions of farms worldwide. In developing pressurized irrigation technologies, particularly for field crops irrigation, researchers and manufacturers have developed more specialized and expensive technologies with sophisticated and intricate hardware. These new technologies have benefited only the large and wealthier farmers leaving the smallholders to remain confined with conventional methods of irrigation. This paper discusses the design, performance, and applicability of a low-pressure water sprinkling nozzle, named LERN. This nozzle can be operated satisfactorily over the operating pressure range of 79-117 kPa. The water application rate of LERN is reasonably high, i.e. 20-23 mm h-1; therefore, field crops such as rice, wheat, oil seed etc. can be irrigated quickly and efficiently even at small plots, where available options such as impact sprinklers are, in general, neither feasible nor applicable due to high pressure requirement (196 - 294 kPa), non-divisibility over small plots, and relatively high cost of pumping and system networking. Since the pressure requirement at the nozzle head reflects overall cost of a pressurised irrigation system, LERN holds greater promise in development of a cost effective pressurized irrigation system for irrigating field crop even at small plots.