What are pivot irrigation systems and how do they work?

Pivot systems are rainwater circular systems for mechanized irrigation, which come as close as possible to the natural way of irrigation provided to us by nature through rain. The founder of mechanized sprinkler systems is the American company Valmont, which created the brand of irrigation systems Valley.One machine consists of a pivot center that feeds with the required amount of water to arms from pipes of different lengths and diameters, support towers allowing the shoulders to move, a transmission ensuring smooth movement and sprinklers, through which water is distributed evenly, covering wide watering limits. The arms move around the pivot center by setting a different speed of movement, the supplied irrigation rate is adjusted according to the needs of the plant in its different phases of development. The systems also offer zone control that allows stopping the supplied water in a certain area in which we do not want to be watered. This precession is recommended when we would like to grow different crops under one irrigation system, as well as when we have different soil characteristics that have different water needs. Some of the possibilities and advantages that such a system gives are: 1. uniform distribution of water not only horizontally, but also in depth, which is important for the proper development of the root system; 2. creation of an optimal water and air regime; 3. reduced consumption of water, energy and labor, due to the possibility of monitoring and controlling the system from a distance; 4. the possibility of equipping the system with a removable piping pivot center, and with a single pivot system it will already be possible to serve several fields; 5. depending on the shape of the field, it can be choose also a variety of pivot - the so-called linear ones, which cover as much as possible the dimensions of rectangular field.The pivot system is modular and allows greater flexibility and the possibility of configuring the pivot according to the characteristics of the field - geography, topography, shape and size, as well as relative to the crops grown on it. They can be fed from any water source such as a river, concrete or ground channels, a dam or a borehole, from which water is brought to the pivot center through a pipe. The pressure in the system required for spraying is created by a pump, and these systems, in comparison with tubular - roller rain machines and with drip irrigation, require a lower pressure - about 2-3 bar, which makes them also lower energy. When supplying the system with water from a pressure network and a hydrant, a pump is not even needed. The electricity of the system is provided by a diesel generator or connection to an electrical network, if available nearby.The cost of pivot systems can vary from 150-350 BGN/ha depending on the area it serves, and the larger the area the more profitable the system is. At the same time, the sturdy construction of galvanized steel and connections of the elements give the machine a long service life - about 20 years, which makes it even more profitable.Any farmer would like to be independent of climatic conditions and ensure a stable yield of his crop. With the opening of measure 121 “Modernization of agricultural holdings”, which is scheduled to open on 20.05.2013, it will be possible to finance projects for the implementation of mechanized irrigation systems.Combining the opportunities provided by the European Agricultural Fund, the desire of farmers and the professional attitude of representatives of manufacturers of mechanized irrigation systems, who will prepare the project and participate in installation, the construction of the systems becomes a desired and possible task to realize.