Considering that the pressure in drip systems should be between 0.5 and 1.5 atm, the system should not be installed with more than 10% sloping land with a single main pipe. This problem can be solved either by means of special drip pipes operating under high pressure or by using pressure reducing valves. On the other hand, on sloping land, drip pipes should be placed perpendicular to the slope, ie parallel to the curves of the spindle. In this way, the flow difference between the first drip head and the last drip head is avoided. Knowing the soil structure of the land on which the system will be built is also very important.
Because, the reaching time of the water, that taken from a dripper with constant flow rate per unit time, to the plant root area depends on the soil structure. This is an important criterion for knowing the minimum irrigation time.
b. Plant Type to be Planted: It is necessary to know the plant species, plant height and crown trace area to be planted in drip irrigation systems. The amount of pipe to be used, the dripper range and the dripline lengths can be determined in the light of this information.
c. Planting Range and Distance: Knowing the planting range and distance of the saplings to be planted is required to determine the pipe thickness, dripper spacing and line length to be used and to calculate the total amount of pipe that will be used.
d. Condition and Distance of Water Source: Before the installation of the drip irrigation system, the water to be used should be well water, open channel water or stagnant pool or pond water and it should be ensured that the water source is in sufficient flow. The location of the water source relative to the land is also important. If the water supply is lower than the field, the engine power to be used will be higher and if it is located higher than it the required engine power will be less. On the other hand, the distance of the water source to the land is also important for the calculation of the length of the main carrier pipe to be used.
e. Quality of Water: Water to be used in drip irrigation should not be too salty. If salt water is used in drip irrigation system, it causes salt accumulation in the vicinity of the plant and there is a danger of salting in the field. On the other hand, too much mossy, silty water should not be used in drip irrigation unless it is well filtered. Water used for irrigation purposes has more or less lime and can clog drip holes over time. Therefore, water should be prevented by adding acid in the amount of lime content of the water while watering.
f. Technical Specifications of Materials to be Used: Nowadays, drip pipes are made using the most point welded drippers. The dripping capacity of the drippers produced at constant pressure per hour is obvious and must be learned from the dealer. There are drip pipes with 2-4 liter / hour drip capacity on the market. When determining line lengths and dripper numbers, the pipe diameter and the dripping capacity of the drippers should be considered.
In addition, if the main pipe to be used will remain on the soil surface, it must be made of materials that are not affected by the harmful effects of UV rays. Besides, the filtration capacity of the filters to be used and the maximum flow rate of the main pipes should be known.
g. Economic conditions: Drip irrigation system is very high cost per decare considering the income level of our country. Before the installation of the system, the cost should be clearly determined and then the project should be implemented.
In drip irrigation systems, all pipes and drippers are asked to be black color except the main pipes. Thus, the positive effect of sunlight on algae growth is prevented. The algae formation in water flow paths is also prevented by this way. Lateral pipes are planned to keep the dripper flow differences along the lengths at acceptable levels. The main reason for the high efficiency of the drip irrigation system is that the fertilizer is applied together with irrigation water. Keeping the irrigation water in small amounts at frequent intervals rather than in large amounts, is of great importance to keep the soil moisture within the field capacity limits. Properties of Drip Irrigation Pipes. Drip irrigation pipes must be protected against natural conditions, especially sunlight (ultraviolet rays) Otherwise, dispersions may occur in the pipe. The dripper and the PE pipe must be properly connectedPE pipe wall thickness should be homogeneous, inner and outer surfaces should be smooth and shiny. Dripper flow rates must meet the pressure-flow-pipe extension distances given by the manufacturer. Otherwise, serious problems can arise between projecting and implementation. It can be tested in field conditions by using a scaled container. The drip irrigation pipes should be supplied to the market by the manufacturer after performing life (aging) tests. For this purpose, suitable PE raw material should be used with the appropriate mixture. PE round pipe must be resistant to events such as pulling, breaking, abrasion etc. This can be simply tested. Force is applied by holding the pipe at both ends. If there is rupture, we may say that there is not enough elasticity for the pipe. 100% elongation can be tested for a good PE pipe. There should be no cracking and breaking in the pipes. A new pipe can be tested like this: The pipe which does not break-crack even though it is bent and opened several times (can be 100 times) from the same point is the appropriate pipe. The same test also gives an idea for pipe surface wear. Determination of water requirements The number of drippers that a garden tap can feed; 300 drippers (2 lt/hour) of 16 mm diameter pipes and 180 drippers (4 lt/hour). Irrigation water requirements of the plant vary according to the plant type, plant growing area, length of the growing season, average temperature, rainfall and air humidity.
For the planning of the irrigation system, designing and achieving it is important to know the consumption of water requirements of the plants in different climatic areas. The most effective way to determine whether plants need water is to take soil samples from the root of the plant and canopies. When this pattern is squeezed between the fingers and the palms of the hand, the result is taken as a criterion in deciding whether the irrigation time has occurred. If the samples were extremely moist (if water or mud was released during pressing), this would mean that the irrigation should be delayed. If at the end of the compression process (squeezing) it does not see the age, or if after pressing the plant, a firmer stroke results in cracking and scattering, this means that there is a delay for irrigation and should be irrigated as soon as possible. Each soil has a different capacity for retaining water. The water retaining capacity varies depending on the soil structure. Water retention capacity affects the time of irrigation and the amount of water for irrigation. The most commonly used methods in our country are tansiometers and moisture meters along with observation detection. The most important thing to consider when using these methods is the fact that water retaining capacities are different.Sand soil holds less water than clay. Because of this, these types of soils shold be irrigated more offen and the water shold be decreased for each irrigation. Since clay soils have high water retention capacity and low water intake capacity, watering is done at longer intervals, and more water is used for irrigation. Cleaning and control of the drip irrigation pipeline In the drip irrigation systems, if you do not take care of the drippers, capacities, there may be a stoppage. The biggest problem of the drip irrigation system is the blockage of the emitters in the pipes. This problem is caused by poor water quality for irrigation. Especially in areas where saline water is used as irrigation, the drippers are clogged if the filter is not used. In order to clean the drip irrigation pipes and meet the requirements of nutrients, it is best to apply phosphoric acid or nitric acid during the watering season. During the watering season, the process should be repeated every 17 to 20 days, 1 liter per decares. Prior to giving the acid to the irrigation system, it is necessary to ensure that clean water is reached the necessary operating pressure. The acid is then given for half an hour, and then sufficiently pure water is used to prevent acidic water in the intestines. In addition, when you do not care, the dirt accumulates. To clean this waste, the end of the pipe should be opened and the water should be applied until it is cleaned. Measures to be taken against pests such as insects and rodents during the irrigation season should be applied to pesticides. Attention should be paid to insect protection, especially when irrigation is not required. Insect damage is generally increased when the tubes are not used for a long time. In addition, when the tubes are used, animals such as birds, crows and dogs damage places where the hoods are located. At the end of the season, when removing the hoses from the field, make sure that no damage occurs. Collected rollers should be protected from damage to rodents such as mice in the warehouses in which they are stored. Drip Irrigation Pipe Calculation Chart