Uniform water supply during the growing season significantly impacts the successful cultivation of carrots. At the germination stage, it is essential to ensure optimal moisture in the soil’s seeding layer; otherwise, germination may be difficult and uneven.
The beginning of the root thickening phase is critical concerning water needs, so adequate soil moisture must be ensured at this time. Depending on the cultivar, this phase occurs 50 – 70 days after sowing. If rainfall does not provide sufficient moisture, irrigation (20-30 mm) is necessary.
During the maximum growth phase of the thickened root (80 – 100 days after sowing), the roots may crack if irrigation is excessive.
Carrots are irrigated using sprinklers.
This irrigation method distributes water over the soil surface in the form of natural rain.
Advantages of Sprinkler Irrigation:
- Usable in various topographical conditions.
- Minimal or no preparatory work on the land.
- Does not occupy arable land.
- Does not hinder the use of machinery.
- Allows economical use of available water due to precise dosing.
- Less exposure of soil to physical degradation.
- Suitable for irrigating newly sown fields and young plants.
- Allows fertigation (fertilization through irrigation).
In sprinkler irrigation, the system takes water from a source, presses it through pipes, and distributes it over the irrigated surface in the form of natural rain using sprinklers.
The irrigation system can be portable, semi-stationary, or stationary.
In the portable system, all parts are movable, and the pipes are connected using quick-connect couplings.
The semi-stationary system has a fixed water intake device and main pipeline, while the sprinkler wings and sprinklers are movable. The main pipeline is usually installed underground, with hydrants extending to the surface for connecting the sprinkler wings.
The stationary system has all parts fixed. The sprinklers are connected to a pipe network usually installed underground.
Each sprinkler irrigation system consists of a water intake, pipe network, sprinklers, and fittings. The water intake can be gravitational or use a pump unit. In pump unit water intake, water is drawn from the source and pressured through the pipe network to the sprinklers. The pump unit consists of a drive motor and a pump, most commonly centrifugal pumps. It is crucial to match the power of the drive motor with the pump’s requirements.
The pipe network serves to convey water from the source to the sprinklers. This network consists of suction pipes, the main pipeline, and sprinkler wings. Sprinkler wings have outlets at certain intervals for connecting sprinklers.
Sprinklers play a final role in the sprinkling system. They spray (distribute) water over the soil surface in the form of droplets. Given their crucial role, they must operate correctly and efficiently. Sprinklers can vary according to water pressure, throw distance, water output, sprinkling area, sprinkling intensity, type and number of nozzles, driving method, and sprinkling method.
Selecting the right sprinklers is essential for irrigation. Light sprinkling is most favorable for vegetable crops, making low-intensity and short-throw sprinklers ideal.
One of the most important features of sprinklers is uniform sprinkling. Wind blowing during irrigation disrupts ideal sprinkling. Typically, most water falls around the sprinkler, decreasing towards the end of the throw range. To achieve more uniform sprinkling over the entire area, sprinklers are appropriately spaced across the irrigated surface.
Besides sprinklers, the optimal arrangement of the entire system is crucial for effective irrigation. The position of the water intake, main pipeline, and sprinkler wings can vary. Choosing the right setup depends on the water source, topographical conditions, and the size and shape of the plots. Therefore, for each plot, it’s necessary to consider natural, technical, technological, and economic factors before deciding on the placement of the system’s components.
In sprinkler irrigation, knowing the duration of sprinkling from one sprinkler position is crucial. If sprinkling lasts longer than necessary, it will add an excessive amount of water to the soil (crop), potentially causing several issues: soil physical degradation, nutrient leaching, erosion, and salinization.
In the case of shorter-than-necessary sprinkling, the soil will not be saturated to the required depth at the field water capacity.
The irrigation dose will depend on soil characteristics, the crop, and the current soil moisture condition.
Proper water dosing is very important in irrigation practice.
The irrigation dose is the amount of water applied in one irrigation event (m3/ha or mm). The dose should saturate the soil to the field water capacity, which means the irrigation dose depends on the soil type. To determine the irrigation dose, it’s essential to know the soil moisture before irrigation and the soil’s water properties. The difference between the field water capacity and the current water content in the soil represents the irrigation dose.
The start of irrigation marks the precise moment for applying the irrigation dose, which is one of the conditions for successful and efficient irrigation. If the irrigation start time is determined “by eye,” irrigation becomes inefficient and can be harmful.
To determine the optimal irrigation start time and set the irrigation dose, thus enabling economical and efficient water use, soil moisture meters are necessary.
