Irrigation system, water from the source, the area to be irrigated and distributed to the necessary structures, vehicles, machines and so on. elements. Each irrigation method has its own irrigation system. For this reason, firstly the most suitable irrigation method is selected by considering the existing water source, soil, topography, plant, climate, economic situation, social and cultural situation, and then the irrigation system required by this irrigation method is planned and the system elements are dimensioned (projected). installed and operated.
A-SURFACE IRRIGATION METHODS In surface irrigation methods, water is taken from the field head channels or lateral pipelines to the field plots and proceeds with the effect of gravity on a certain slope on the land surface. During this progress, water enters the soil with the infiltration of the soil and the plant is stored in the root zone. In areas where surface irrigation methods are applied, the transmission and distribution of water to the field parcels are generally done with open channel systems. However, low pressure pipe systems can sometimes be used due to topographic conditions. Surface irrigation methods; release, pans and furrow irrigation.
1-Keel Irrigation (Wild Irrigation) Method In keel irrigation method, water taken from field head canal to field parcel is left to spread randomly along the parcel. As water proceeds on the soil surface, it also enters the soil by infiltration. In this application, the slope in the irrigation direction should not exceed 3%, should not be perpendicular to irrigation and the field should be leveled. A different application of the release irrigation method is to inflate the water from the field canal by inflating it and spread the overflowing water along the field parcel. Theoretically, it is envisaged that water will flow by covering the soil surface in a layer. However, in practice this condition does not usually occur. The water moves irregularly in the direction of the slope, resulting in a water distribution that is often unequal. In other words, more water is required in certain parts of the field parcel and less water is required in certain parts of the field parcel. Therefore, water application efficiency is extremely low. The only advantage of the release irrigation method is that the initial plant cost is very low. On the other hand, this method is not recommended when taking into consideration the disadvantages such as lack of uniform water distribution throughout the field plot, extremely low water application efficiency and the possibility of salinity and sodium problems in the soil.
2-Pan (pond) Irrigation Method In the pan irrigation method, the field parcel to be irrigated is surrounded by soil sediments and divided into sloping lower parcels. These sub parcels are called pans. Water is taken from the field head channel or lateral pipeline to the pans in one or more places. The pan flow is high enough to allow the water to pond in the pan as soon as possible. The water that is ponded in the pan enters the soil when the soil absorbs water (infiltration) and is stored in the plant root zone. The facility cost of the pan irrigation method is as low as the keel irrigation method. Water can be controlled better than the release irrigation method, but the irrigation efficiency is also low in this method. In addition, the pans should be sloped and require land leveling. Since the pan flow is high, special structures may be required to prevent erosion at the beginning of the pan, requiring controlled irrigation to prevent deep infiltration, otherwise an underground drainage system may be required, which increases the cost.
3-Furrow Irrigation Method In furrow irrigation method, small canals called furrow are opened between the rows of plants and water is given to these furrows. As the water travels along the furrow, the soil is stored in the plant root area by infiltration. During irrigation, a large number of furrows are fed simultaneously. The number of furrows given at the same time constitutes a furrow irrigation group. In furrow irrigation systems, there is a need for sloped distribution channels or perforated furrow irrigation pipes that serve each furrow irrigation group after the field head or lateral pipeline. These pipes are portable and are transported to another group when irrigation of one furrow irrigation group is completed. Among the advantages of furrow irrigation method; Although the initial plant cost is higher than other surface irrigation methods, it is still low, a good land leveling and irrigation plant can be considered to achieve a good irrigation efficiency, can be safely applied in heavy soils. The factors limiting the application of the method are; surface drainage canals may be required to remove water from the furrow, a good land leveling is required to provide an acceptable level of uniform water distribution, salt that may accumulate on furrow ridges may be a problem for soil salinity sensitive plants, falling rainfall surface flow o