Focus on foreign agricultural water-saving irrigation design

Micro-irrigation technology is the first in Israel. The most representative countries in the world for the development of micro-irrigation technology are the first to push Israel. The greenhouse cultivation of all countries uses micro-irrigation, mainly drip irrigation. Israel has a number of world-renowned irrigation companies, such as Neftem, Plasto, Metz, and Ray Gull.
The highest water utilization rate of drip irrigation water in Israeli greenhouses is 95%, and its drip irrigation products fall into two categories: one is dropper type and the other is drip emitter type. Currently popular is the integrated drip irrigation pipe (band), that is, the combination of dripper and drip irrigation pipe is complete, and installation and use are very convenient. Dripper spacing is generally 30,50,75,100 cm, wall thickness from 0.15 to 2 mm, and some use, some life can be as long as 20 years. The latest products are pressure-compensated insert-type pipettes, which effectively improve the uniformity of irrigation and facilitate the distance-to-mechanical laying. There are many types of drippers, such as pipe-type drippers, detachable drippers, and pressure-compensated drippers. Its newly developed pressure compensated dripper can adjust the flow rate by changing the length of the water flow channel, and the state of entering the pressure compensation is faster and the uniformity is higher, and a filter device is also installed at the inlet of the water flow. The self-rinsing function at the beginning and end of the operation reduces clogging.
Israel has developed a series of micro sprinkler products for greenhouse irrigation. Each nozzle consumes about 30 to 300 liters of water per hour, with a spray radius of 1 to 6 meters. This irrigation method can make the effective utilization of water reach 85%. Israel has developed a series of slit type, refractive type, rotary micro sprinkler and connector products, good material, wear resistance, spray effect. The pulsed micro-irrigation technology introduced by Israel in recent years represents the application of a new irrigation method, which has better water-saving effects but at a relatively high cost.
The adoption of the micro-irrigation method has brought great changes to the fertilization technology. It has led to a completely new concept - the rise of water and fertilizer irrigation, drip irrigation system for fertilization, direct contact with the roots of plants, can avoid waste, which is the general fertilization Methods do not have. The application of automatic fertilization system has been very extensive. Fertilizers are controlled by computers or small controllers to realize precise fertilization. There are mainly pump injection method, Venturi type, differential pressure type, water-driven mixed injection type, etc., in which water-driven mixed injection. The application of type is more and more extensive.
Israel has many manufacturers specializing in the production of filters. According to the needs of users, it can provide filter stations composed of several to several tens of filters. It is specially used for the treatment of micro-irrigation water sources and has a high degree of automation. It uses solenoid valves to control switches and backwashes. . The main products are mesh, laminated, centrifugal, sand filter. The new laminated filter features: First, the lamination flow channel design uses a curved surface to increase the transition area, expanding the water flow, reducing the head loss; Second, the design of the backwash flow channel, does not need to open under normal working conditions The backwashing dirt can be easily realized by rotating the shell only at a certain angle, which is very convenient.
The micro-irrigation method is generally controlled by computers. The humidity sensor under the cultivated land can transmit information about the soil moisture, and another sensor system can determine the irrigation interval of the plant by detecting the diameter change of the stem and the fruit of the plant. In greenhouses and other facilities, more use of small irrigation controllers, this equipment can usually control a few or more than a dozen roads.
In Israel, there have been farmers who use computers to control the irrigation process at home. In addition, Israel has also developed several series of matching valves for agricultural automatic irrigation. Such as electric and hydraulic remote control solenoid valves, pressure reducing valves, pressure regulators, safety or check valves, check valves and flow control valves.
The number of areas in the United States of micro-irrigation The United States is currently the world's most promoted micro-irrigation area in the country, in 1991 it has exceeded 600,000 hectares. It accounts for about 3% of the total irrigated area in the United States. The turbulent pressure compensating drip irrigation belt developed and produced by Rain Bird Company has good anti-clogging performance, and the pressure compensation function makes the water even and can be buried underground to reduce the evaporation loss. Micro sprinklers are rich in varieties, mainly refraction type and rotary type, each series has a variety of nozzles and a variety of spray forms, and can be easily installed and disassembled and cleaned. The supporting products are also well-developed and include a series of strainer filters, pressure regulators, fertilizer-agricultural injectors and various types of controllers. Fertilizer-Pesticide Injector is a special device that pumps continuous injection of solution into micro-irrigation pipelines. It has 1 to 4 flow paths, injection flow rate is 0 to 57 liters per hour, and each channel is equipped with a flow meter and a regulating valve. Solenoid valve products are also very rich in product specifications, some products with a filter function, can be cleaned under operating conditions, and some products with pressure regulating components to ensure constant pressure. The controller has mechanical and electronic and electronic AC and DC controllers and can control up to 120 solenoid valves. Four kinds of control programs can be set, one station can be opened multiple times in one day, which is suitable for frequent micro irrigation. The use of automatic irrigation control in the greenhouse is particularly effective.
Australia is also good Australia is one of the countries in the world that promotes micro-irrigation. The base manufactured thin-wall drip irrigation dripper affixed to the inner wall of the drip irrigation belt, with multiple inlet inlet filtering, turbulent flow channels and laser throat outlets, improved the anti-blocking capability and reduced the invasion of rhizomes. Australia has also developed a number of compensating drippers and micro sprinklers. The microsprayer uses a flow equalizer to make it pressure compensating. When the pressure changes, it keeps the water even, and can meet various irrigation patterns and the irrigation needs of different crop growth periods.
France leads the new trend France's fertilizer and pesticide mixer represents the current international advanced level. Its working principle is: water flows into the mixer, drives the main piston, and the injector piston connected with it moves up and down to inhale the fertilizer to be injected ( The pesticide solution enters the mixing chamber. Its characteristic is that it does not rely on electric power and it is driven by hydraulic pressure. It can regulate the concentration and has a high precision control capability, which greatly improves the fertilization accuracy of conventional differential pressure fertilisers.