Advanced technologies applied to hose reel rain gun machines: new perspectives towards sustainable sprinkler irrigation.

The paper describes some outstanding technological innovations and improvements of hose reel rain-gun machines related to working characteristics, application efficiency, distribution uniformity, energetic performance and economic profitability. During time, electronics and control units evolved, and the improved quality of polyethylene enables the industrial production of bigger and longer pipes. Increased efficiency of pumps, hydraulic turbines and transmission systems, result in substantial reduction of energy requirement per unit of irrigated land and supplied water. New rain-gun sprinklers allow high water distribution uniformity and minimal effects of drops on crop and soil. Operating capacity of modern medium-high machines allows to irrigate 50 ha and more of horticultural and industrial crops during peak period under sub-humid climate. Comfort and safety of labour take advantage of the remote control of several operations. Machine handiness is facilitated by hydraulic control systems, resulting in time and labour saving. Fertigation can be practised, allowing significant crop yield increases. Interfacing transmission control of pipe rewinding, field mapping, Global Positioning System (GPS) technology, sprinkler rotation speed and wetting angle, gives the possibility of precision agriculture, also increasing irrigation efficiency. The latest rain-gun machines can practice precision farming, having the chance to irrigate irregular field shapes. The expected step in next future is to practice precision irrigation.