In general, it is a difficult task to make the sprinkler irrigation system on the slope zone meet the water requirements of the crop and to manage it easily. Effectively addressing the water requirements of slope crops is a challenging task, too little water affects crop growth, and too much water creates many other problems.

The main challenge is how to avoid surface runoff without eroding crops and the ground while meeting crop growth requirements. The following 10 design, product selection and installation techniques are used to effectively solve the ground runoff problem in slope irrigation:

1. In order to reduce surface runoff, the system should choose an irrigation timer that can control the irrigation time, ie controller (such as Rain Bird E-Class, ESP-LX+ controller, etc.). Each program should have at least 4 different start-up times, first determining the time required for each station to generate surface runoff, thereby adjusting each irrigation time. If necessary, different start-up times can be used to change the ground runoff caused by the long running time of the solenoid valves of each station, or to select a high-grade controller (such as the Rain Bird ESP-MC controller), which can provide intermittent irrigation. That is, the total irrigation time is divided into several cycles, and sufficient time is left between the cycles to allow water to penetrate into the soil to avoid surface runoff.

2. Use the main valve and flow sensor equipment to increase the system insurance factor. When irrigating the slope, it is important to use the main valve and flow sensor. The main valve is installed in front of the solenoid valve of each station and around the slope to reduce the pressure on the main pipe. A closed main valve supplies water to the main line only when it receives a controller signal. This equipment reduces the chance of nozzle damage, pipe rupture and solenoid valve damage.

The flow sensor detects changes in flow when problems occur. If properly calibrated, the sensor and main valve will work together to shut down the system in the presence of additional flow to protect the slope crop and ensure system safety.

3. Use the reverse diaphragm solenoid valve to reduce the problems caused by the diaphragm damage of the solenoid valve. The internal structure of the valve is different from that of a general solenoid valve, and when the diaphragm of the solenoid valve is damaged, the water flow can be effectively cut off. In other words, the reverse diaphragm valve is effective because it can shut off the water source when it is not "off" when it is not working. In general, the solenoid valve is in the "open" state when the diaphragm is damaged, and the water will continuously erode the crop before it is effectively repaired.

4. Use pressure-compensated or pressure-regulating equipment to achieve the best spray results. When the pressure regulator model matches the performance on the manufacturer's instructions, the pressure regulator mounted on the solenoid valve adjusts the downstream working pressure. At the optimum working pressure, the nozzle is most likely to achieve an effective and uniform spray effect. If the nozzle pressure is lower or higher than the working pressure, the spraying effect is not good, and as a result, the crop is damaged and there is a possibility of erosion.

The use of a nozzle with built-in pressure compensation or pressure regulator is the best way, because the appropriate working pressure is directly applied to each nozzle (such as the optional rain bird 1800 with pressure adjustment function, UNI-Spray series nozzle). The rotor pump is beneficial to eliminate the atomization generated by the pressure and reduce the airflow caused by the wind, and can provide an optimal water drop displacement condition to protect the growth of the crop.

5. Adjust the branch pipe spacing to compensate for problems caused by the slope. For example, for a slope of 1:2, the spray radius can only reach 80% of its range above the nozzle installation site, while the spray radius below the nozzle can reach 120% of the range. This concept is difficult for many people to understand because the area covered by the slope on the irrigation project design plan is smaller than what they actually do, and the slope effect cannot be correctly reflected from the map.

Therefore, the nozzle spacing should remain constant along the direction of the branch pipe. In the direction of slope, from the bottom of the slope to the top of the slope to the top of the slope, the distance between the branches should be small to large, and the spacing between the top nozzles should be the range of the nozzle.

6. Arrange the branch pipes along the contour line. When installing the branch lines, make sure they are arranged along the contour line. If the branch pipe is incorrectly installed along the slope direction, an imbalance of pressure due to the change in the height difference will occur, causing a change in the uniformity of the irrigation.

In addition, the high pressure zone at the bottom of the bevel reduces the life of the sprinklers and tubing.

7, each round irrigation area, the number of nozzles can not be too much to reduce potential hidden dangers. When you increase the number of nozzles in a certain area, the system piping and engineering structure will change, and when the system is shut down, damage may occur due to other reasons (such as water hammer). Therefore, it is generally not recommended to enlarge the system unless the system is equipped with other protective equipment (such as pressure reducing valves, intake and exhaust valves, etc.) to avoid some potential hazards.

8. Limit the number of nozzles in each wheel irrigation area to improve the spraying effect. Considering the effects of plant species, rainfall, sunshine, wind direction and other meteorological factors on different areas of the slope, the slope is divided into multiple irrigation areas to fully meet different requirements. If you mix different plants in one irrigation area, it is difficult to make the crop grow healthily.

9. The full-circle nozzle and the adjustable-angle nozzle are divided into different wheel irrigation areas. The adjustable angle nozzles are arranged in a separate wheel irrigation group, so that the irrigation time can be adjusted to make the rainfall uniform with the full circle nozzle wheel irrigation group. A better method is to choose a nozzle with matching rainfall intensity, that is, when the different spray angles are changed, the rain intensity of the nozzle remains unchanged (such as the Rain Bird 1800 series MPR nozzle), which ensures that all the nozzles have the same rainfall and uniform irrigation. High degree.

10. Install the spill valve to avoid erosion. Make sure that the spill valve is properly installed. When the terrain height difference is changed, when the zone solenoid valve is closed, the water in the high pipe can be prevented from flowing out from the lower nozzle. This will reduce the erosion of green areas or crops around the slope. Before installation, check that the nozzles have a built-in anti-overflow valve, which reduces the need to install a separate relief valve under each nozzle.

Note: Because many slope greening does not use lawns to plant other vegetation, it is recommended to use 6" (15cm) or 12" (30cm) lifting nozzles instead of rocker nozzles with risers, not only because the lifting nozzles improve working conditions. And it is concealed and not subject to human damage.

Effective slope irrigation includes pre-planning, proper installation and reliable maintenance and maintenance techniques. If these three can be solved very well, many of the problems of use, maintenance, and capital can be reduced, and the crops on the slope can grow healthily.