Nozzle selection and management of pivot irrigation - taking into account the soil infiltration capacity

Abstract

Centre pivots or moving laterals are able to perform a very uniform irrigation. One of the obstacles to the extension of such systems is the very high intensity of the irrigation they distribute . It can exceed some soil infiltration capacity. The main factors that characterize pivot irrigation for a given plot are reviewed: types of sprinklers, nozzles, functioning pressure range, wind resistance, droplet diameters. These elements allow to compute the maximum value of the applied watering intensity by a given sprinkler type. The water application curves obtained are then compared to the soil infiltration curves to select the appropriate types of sprinkler. The influence of the daily application and sprinkler range on watering intensity is illustrated and discussed. A graphical method is proposed for assessing the maximum amount of irrigation water avoiding runoff. Additional information is given on water application intensity calculation, standardisation, market evolution, system cost, and on the WPDiBus software, used to compute and diagnose the functioning of devices designed by Cemagref. A brief literature review is provided.