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

Abstract

Pressurized irrigation technologies of course have the potential to raise the productivity of land and water; but, these technologies could no t popularize among the smallholders who own millions of farms worldwide. In developing pressurized irrigation technologies, particularly for field crops irrigation, researcher s and manufacturers have developed more specialized and expensive technologies with so phisticated and intricate hardware. These new technologies have benefited only the larg e and wealthier farmers leaving the smallholders to remain confined with conventional m ethods of irrigation. This paper discusses the design, performance, and applicabilit y of a low-pressure water sprinkling nozzle, named LERN. This nozzle can be operated sat isfactorily 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 s eed etc. can be irrigated quickly and efficiently even at small plots, where available options such as impact sprinklers are, in general, neither feasible nor ap plicable 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 r equirement at the nozzle head reflects overall cost of a pressurised irrigation s ystem, LERN holds greater promise in development of a cost effective pressurized irrigat ion system for irrigating field crop even at small plots. Keywords: Coriolis force, Developing world, Jet breaking, Op erating pressure, Smallholders.