Fruit tree drip irrigation is a special equipment that filters pressurized water (pressure that can be pressurized by the water pump or use the topographical drop) and pass through the various water distribution networks (including the main pipe ,supervisor, branch pipe, capillary tube and the gate valve, etc.) to the dripper, the water is dripped directly from the dripper into the rhizosphere soil of the crop. After the water drops into the soil, a small saturated zone is formed under the dripper by means of vertical force infiltration, and then gradually spreads to the developed areas of the crop roots.
The drip irrigation technology uses a series of plastic pipes with different calibers to directly transport water and fertilizer dissolved in water from the water source to the root of the crop through the pressure pipeline. The water and fertilizer are supplied at regular intervals as needed.
Introduction of composition
The drip irrigation system consists of four parts: water source engineering, first hub (including water pump, power machine, filter, fertilizer injection device, measurement and control instrument), water distribution pipeline at all levels and full head, etc. The main components of the system are as follows.
1.Power and pressure equipment. These include pumps, electric motors or diesel engines and other power machinery. These devices are the power and flow source for micro-irrigation systems, except for self-pressure systems.
2.Water purification equipment. There are sedimentation tanks, primary trash racks, swirling splitter splitters, screen filters and media filters. A combination can be selected according to the water quality conditions of the water source. The main function of the screen filter is to filter out suspended matter in the irrigation water to ensure that the entire system, especially the dripper, is not blocked. Screens are made of nylon or corrosion-resistant wire.
The size of the mesh depends on the size of the dirt particles to be filtered. Generally, the sediment of 75 microns in diameter is removed. A 200-mesh screen is required. The gravel filter is made by washing and sorting sand gravel and sand, and is filled into the metal cylinder in a certain order. It has good filtering effect on various organic or organic sewage and suspended algae. . The cyclone splitter splitter separates the sand with a specific gravity greater than water from the water by centrifugal force, but does not remove the organic matter.
3.The water flows from the capillary into the dripper, which injects the irrigation water into the soil at a certain working pressure. It is the heart of the drip irrigation system. The water is dripped or exuded through a dripper at a constant low flow rate and diffused in the soil in the form of a non-saturated stream under the dripper. At present, the dripper used in the actual drip irrigation project mainly includes two types of dripper and drip irrigation belt.
4.Fertilizer and pesticide injection devices and containers. Including differential pressure fertiliser, venturi injector, diaphragm or piston injection pump, fertilizer or pesticide solution storage tank. It must be installed in front of the filter to prevent the last dissolved fertilizer particles from clogging the dripper.
There are three ways to inject fertilizer: one is to use a small pump to hydraulically feed the fertilizer into the main pipe; the other is to use the pressure difference caused by the flow regulating valve on the pipe to inject the fertilizer into the main pipe; the third is the jet. injection.
5.Control and measurement equipment. Including water meters and pressure gauges, various manual, mechanical or electric operated gate valves, such as hydraulic automatic control valves, flow regulators, etc.
6.Safety protection devices such as pressure reducing valves, intake and exhaust valves, check valves, drain valves, etc.
Introduction of two drops of water
The dripper is the core of the drip irrigation system and meets the following requirements：
1.There is a relatively low and stable flow rate within a certain pressure range, and the outlet flow rate of each dripper should be between 2 and 8 liters/hour. The flow path of the dripper is small, the diameter is generally less than 2 mm, and the precision of the flow channel manufacturing is also high. The small flow path difference will have a great influence on the outflow capacity of the dripper.At the same time, the frictional resistance of the water flow in the flow of the capillary reduces the pressure of the water flow, thereby reducing the flow rate of the tip dripper.
In order to ensure sufficient irrigation uniformity of the drip irrigation system,the flow difference in the system is generally limited to 10%.
2.Large flow cross section In order to generate a large pressure loss and a small flow rate at the dripper section, the minimum dimension of the water flow passage section varies between 0.3 and 1.0 mm. Due to the small flow path of the dripper, it is easy to cause blockage of the flow path. If the dripper flow path is increased, the flow path needs to be lengthened. For this purpose, various drip devices have been developed.
Introduction to the classification and characteristics of the dripper
According to the connection method of the dripper and the capillary tube
1.Inter-tube dripper: Install the emitter in the middle of the two-stage capillary so that the dripper itself becomes part of the capillary. For example, a barbed joint at both ends of a tubular dripper is inserted into a two-stage capillary tube, so that most of the water flows through the body cavity of the dripper to the next section of the capillary tube, and a small part of the water flows through the side hole in the dripper body. In the dripper flow channel, the dripper flows out after the flow channel is dissipated.
2.Tube Top Dripper: A dripper that is directly inserted into the wall of the capillary tube, such as a side-drip type dripper, an orifice type dripper, etc.
According to the energy dissipation method of the dripper
1.Long-flow type energy-dissipating dripper: The long-flow type energy-dissipating dripper mainly relies on the frictional energy between the water flow and the flow channel wall to adjust the amount of water discharged from the dripper, such as micro-tubes, internal threads and labyrinths. Tube type dripper, etc.
2.Orifice energy-dissipating dripper: a dripper that dissipates energy by local head loss caused by orifice outflow, such as orifice type dripper and porous capillary tube, all belong to orifice type dripper.
3.Vortex energy-dissipating dripper: the water flows into the edge of the flow chamber of the dripper, and a low-pressure zone is generated in the center of the vortex, so that the pressure at the outlet of the center is low, and thus the discharge flow of the dripper is small. The flow rate of a well-designed vortex drip is less sensitive to changes in working pressure.
4.Pressure-compensated dripper: The pressure-compensated dripper changes the shape of the elastomer component or the flow channel by the pressure of the water flow, so that the surface area of the water-passing section changes, and the dripper flow is small and stable. The significant advantage of the pressure-compensated dripper is that it can automatically adjust the water output and self-cleaning, and the uniformity of the effluent is high, but the manufacturing is more complicated.
5.Drip irrigation or drip irrigation drip: The dripper and the hair control are integrated. The tube (or belt) with both water distribution and dripping function is called drip irrigation tube (or drip irrigation belt). According to the structure of the drip irrigation pipe (belt), it can be divided into two types: the inner drip irrigation pipe and the thin wall drip irrigation zone .
The configuration of the drip irrigation system can generally be to lay a capillary tube between the rows of fruit villages. The dripper with a flow rate of 4 liters/hour is installed at intervals of 1 meter on the capillary tube. The dense planting garden can be placed at a distance of 0.5 meters before and after the fruit trees. head. In general, the orchard will have 1 dripper or 1 dripper around the plant at 1 meter on both sides of the tree before the result (1 meter from the trunk), and 5 to 6 trees or sticky soil. In the absence of rain, the interval between two drippings is 3 to 4 days.
Precautions for using a drip tape
1.It is easy to block the pipe and dripper of drip irrigation, and the water quality is high, so the filter must be installed;
2.It is drip irrigation that cannot adjust the field microclimate. It is not suitable for irrigation during the freezing period. In the irrigation of vegetables, the drip irrigation system cannot be used to apply manure.
3.It is a high investment in drip irrigation, and it is necessary to consider the economic benefits of crops;
4.Burning of the drip irrigation belt Pay attention to compacting the mulch film when laying the drip irrigation belt so that the mulch film is as close as possible to the drip irrigation belt, and no space is created between the mulch film and the drip irrigation belt.
Avoid the focus of sunlight formed by water droplets. Before planting, it is necessary to level the land and reduce the phenomenon of multiple pits. Prevent the clump of weeds from the soil to hold up the mulch, causing water vapor to form a lens effect under the mulch and burn the drip irrigation belt. The drip irrigation belt can be buried while laying to avoid the focus burn.
When using drip irrigation, fruit trees should pay attention to purifying water quality, prevent dripper clogging, and filter with 80-100 mesh nylon sieve water filter made of PVC material that is not easy to rust. The dripper should be cleaned and overhauled frequently.