What issues should be paid attention to when using drip irrigation?

Drip irrigation is a localized drip irrigation method that irrigates crops more precisely according to their needs. It generally saves 30%–50% more water than surface irrigation.  Drip irrigation systems can fertilize while irrigating, and can precisely and balancedly fertilize according to crop nutrient requirements and soil nutrient conditions. Simultaneously, drip irrigation fertilization can directly deliver fertilizer solution to the range of the main crop root activity layer. Crops absorb nutrients quickly without leaching losses, reducing groundwater pollution. Therefore, drip irrigation systems not only increase crop yields but also significantly reduce fertilizer amounts and improve fertilizer efficiency.

       Drip irrigation systems consist of three parts: a filtration system, a water conveyance pipeline, and a field water supply system. The main function of the filtration system is to filter the water, remove wastewater, control the water flow, automatically release the pressure in the system, calculate the water volume, inject fertilizer into the water supply, remove air from the system, and switch water sources. According to the function and different water sources and water quality conditions, it is divided into disc type, net type (controllable filter), and centrifugal type, media filter, or a combination of the above. After filtration, the water is input into the water conveyance pipeline. The water conveyance pipeline is mainly composed of PVC pipes and various PVC pipe fittings and its main function is to convey water. The field water supply system is the part closely related to users, and it is also the most easily worn and damaged part, consisting of field laterals, drain valves, field valves, ends, blind pipes, and drip irrigation pipes. The main function of the field system is to convey water, control the water volume, regulate pressure and switch water sources with field valves, and discharge wastewater to supply water to crops.

       Although drip irrigation systems have many advantages and can improve crop yield and quality, if used and managed improperly, they may not achieve the expected results or may even cause the system to malfunction. Below is how to properly use and manage a drip irrigation system:

     1: Develop a reasonable irrigation regime.   Drip irrigation has a low flow rate, so users often cannot see the irrigation process. If the irrigation time is too long, deep seepage will cause waste. If the irrigation time is too short, the root system will experience water stress. Understanding the irrigation system's irrigation intensity, plant water requirements, and soil field water holding capacity allows for better irrigation according to plant needs. Remember that the irrigation cycle and amount should be adjusted according to the climate and different growth stages of the plant and should not always use the same irrigation regime.

　2: Reasonably select emitters.   Emitters are usually divided into two Models: pressure-compensating emitters and non-pressure-compensating emitters. Although pressure-compensating emitters are more expensive, they are more effective. First, pressure-compensating emitters ensure that each emitter delivers water uniformly, making fertilization and irrigation uniform. Second, some pressure-compensating emitters can flush out debris from clogged emitters, and some pressure-compensating emitters have large flow channels, reducing the possibility of emitter clogging.

   3: The head of the drip irrigation system must be equipped with filtration equipment.    Many users mistakenly believe that well water does not need to be filtered, but in fact, well water often contains coarse sand, fine sand, and some chemicals that clog emitters. Common filters include mesh filters, disc filters, and gravel filters. If the water contains sand, a centrifugal filter should be used. Before installing the filtration system, analyze the physical and chemical composition of the water quality and use appropriate filtration facilities according to the water quality and select emitters with anti-clogging properties.

 4: Fertilize through the drip irrigation system.    Simultaneous water and fertilizer application is the biggest advantage of drip irrigation. Plant roots have hydrotropism and chemotropism, and the fertilizer application efficiency is highest when fertilizer is applied with irrigation water. However, a fertilizer irrigation system should have a device to prevent backflow of fertilizer to prevent fertilizer from contaminating groundwater and other water sources.

 5: Daily maintenance.    Drip irrigation systems require careful maintenance to perform optimally. Units with the capacity should regularly flush the drip irrigation pipes to ensure smooth water flow. Depending on the actual needs, consider periodically using effective chemical treatments. ① Laying of drip pipes: When transporting drip pipes, care must be taken to prevent wear and tear. Lay the drip pipes regularly around the center without tangling them. After laying a roll, connect the next roll with a connector and lay it to the end of the field. After laying a drip pipe, straighten and round any folds and twists slowly, restore the pipeline shape, cut the damaged parts, and connect them with connectors. After laying the drip pipe, cut it the next day (to prevent thermal expansion and contraction, causing the pipeline to shorten), and cut it from the middle of the two laterals and at the laterals. The drip pipes in the middle of the two laterals are overlapped by 3-5cm. ② Testing and flushing: Flushing of the water conveyance main pipe and main and branch pipes: The system design must meet a flushing flow rate of no less than 0.50 m/s during flushing. The system must be flushed according to the following steps: The system is filled with water and the correct working pressure is reached; flush the main pipe, after the drain valve water is clean, close the drain valve; flush the branch pipes and drip irrigation pipes, after the end water is clean, install the end caps. Flushing of drip irrigation pipes: There is no chemical that can solve this problem. Connect the drip pipe and the blind pipe. When the water reaches the end of the drip pipe, the end of the drip pipe can be opened and closed three times to generate pressure fluctuations and flush out mud and sand and production waste in the pipeline. After the water flow is clean, block the end of the drip pipe to prevent water from flowing out, and do not use wire or other hard objects to tie it. ③ Regular flushing: After a drip irrigation system operates for a week, open the end of the drip irrigation pipe once to remove the fine particles accumulated at the end. The pipes must be opened one by one to ensure normal system pressure. Once a month, open the end plugs of each irrigation group in turn and flush the main and branch pipes with high pressure. ④ Rain flushing: When it rains heavily, mud and sand will enter the emitters. After drying, the dirt in the flow channel will precipitate and clog the emitters. To prevent clogging, irrigation should be carried out after the runoff is discharged, usually 1-2 days after rain, which is called technical irrigation because it is only for flushing the drip irrigation system and not for actual water shortage.

 6: Install pressure gauges and flow meters.   These simple devices can help users “take the pulse” of the irrigation system to solve problems that cannot be accurately judged with the naked eye. Using a pressure gauge to check the pressure at the head, middle, and tail of the drip irrigation tube and comparing it with the design pressure or historical water pressure can determine problems with the drip irrigation system. A flow meter can help users quickly determine the flow rate of the water source. In addition, flow data can help calculate the actual flow rate and the historical flow rate of the irrigation system.

 7: Correctly understand the quality of pipe materials.   Different drip irrigation pipes have different raw material qualities, production processes, and patented technologies. More importantly, the emitter structure design of different Brand pipes is different. Drip irrigation pipes that can provide uniform water and fertilizer, have anti-clogging performance, long lifespan, and are easy to install and maintain should be selected.

 8: Long-term running costs    Drip irrigation systems are often used for more than ten or twenty years, irrigating millions of cubic meters of water and fertilizer. Therefore, it is crucial to consider the uniformity of irrigation, the running costs of the pump station, and daily maintenance costs. A well-designed system can reduce later running costs through its good uniformity or energy efficiency. In addition, some suppliers have extensive experience and proprietary technologies that can guide users in selecting the right irrigation system and provide assistance in operating and maintaining the system.