The main technical details of water-saving irrigation in China are elaborated
Channel water transport is currently the main mode of irrigation for farmland irrigation in China. The water utilization coefficient of the traditional canal canal system is generally 0.4-0.5, and the difference is only about 0.3, that is, most of the water is lost through leakage and evaporation. Channel leakage is the main aspect of farmland irrigation water loss. After adopting the channel seepage prevention technology, the canal water utilization coefficient can generally be increased to 0.6-0.85, which is 50%-70% higher than the original earth canal. Channel seepage control also has the advantages of fast water transport, favorable season for agricultural production, land saving, etc. It is currently one of the major measures for water-saving irrigation in China.
According to the materials used, the canal seepage can be divided into: 1 seepage prevention of the three-dimensional soil protection surface; 2 masonry stone (pebble, block stone, piece stone) anti-seepage; 3 concrete impermeable; 4 plastic film seepage prevention (after lining the film With earth, concrete or stone protection) and so on.
Pipeline water transfer is the use of pipelines to send water directly to field irrigation to reduce the leakage and evaporation loss of water during open channel transportation. The irrigation water transport in developed countries has adopted a large number of pipelines. At present, the transmission of water from pipelines in well irrigation areas in northern China is also popular. Commonly used pipes include concrete pipes, plastic hard (soft) pipes, and metal pipes. Pipeline water delivery has the advantages of rapid water delivery, water saving, land saving, and production increase compared to the channel water supply. The benefits are: water utilization coefficient can be increased to 0.95; electricity saving is 20%-30%; provincial land is 2% -3%; increase rate by 10%. At present, if low-pressure plastic pipelines are used to transport water, excluding investment in water project construction (the same below), the investment per mu is 100-150 yuan.
Where conditions permit, it should be combined with the actual development of pipelines to actively transport water. However, water transport in pipelines only reduces water loss in the process of transporting water, but in order to achieve efficient water use, field-saving measures such as spraying and drip irrigation should also be provided. At present, there is no place for supporting spraying and drip irrigation equipment. The requirements for the development of spraying and drip irrigation should be considered for the layout of pipelines and the pressure capacity of pipes, so as to avoid waste.
Sprinkler irrigation is the use of pipelines to send pressurized water to irrigated areas, and dispersed into small droplets through sprinklers, and evenly sprayed into the fields to irrigate crops. As an advanced mechanized and semi-mechanized irrigation method, it has been widely used in many developed countries.
The main advantages of sprinkler irrigation are as follows: (1) The water-saving effect is significant, and the utilization rate of water can reach 90%. In general, sprinkler irrigation can be used as 2 cubic meters of water compared to surface irrigation. (2) Larger crop yields, generally up to 20%-40%. The reason is that the agrarian canals, furrows, irrigation trenches and ridges in the fields have been abolished, and the planting area has increased by 15%-20%; the irrigation is even and the soil is not compacted, which is favorable for rushing seasons and keeping seedlings; and the microclimate and agriculture in the fields have been improved. ecosystem. (3) The workload of field canal construction, management, maintenance, and land consolidation has been greatly reduced. (4) Reduced farmers' expenses and labor for irrigation and increased farmers' income. (5) It will help accelerate the realization of agricultural mechanization, industrialization, and modernization. (6) Avoid secondary salinization of soil due to excessive irrigation. Commonly used sprinkler irrigation pipeline, translation, center fulcrum, reel type and light small units.
The mobile pipeline sprinkler usually fixes the water main pipe underground, and the field branch pipe and sprinkler head can be dismantled, moved and used, thus reducing the investment. This form of irrigation is used in tens of thousands mu of grain fields in the county of Shunyi County in Beijing. More than 10 years of practice has proved that mobile pipeline irrigation has the advantages of simple equipment, easy operation, and low investment, in addition to the advantages of general sprinkler irrigation and water saving, production increase, labor saving, peasant burden reduction, and benefits to agricultural mechanization, industrialization, and modernization. It is adaptable to the size and shape of the field, and can be used by a household or a joint household. It is a micro-sprinkler irrigation system that is more suitable for China's national conditions and can be widely promoted. It can be applied to field crops, vegetables, etc. It is 200 yuan to 250 yuan.
Fixed-pipe sprinkler irrigation is to install pipelines and nozzles in the field and it is fixed. It has high irrigation efficiency and simple management. It is suitable for irrigation of vegetables, fruit trees and cash crops. However, the higher investment (mu investment is generally around 1,000 yuan) is not conducive to mechanized farming.
The central pivoting and translating large-scale pivots can only walk within a predetermined range. There can be no tall obstacles in the walking area and the land requirements are relatively flat. Its high degree of mechanization and automation is suitable for large-scale farms or farms with higher-scale operations. With domestic equipment, the investment per mu is 300-400 yuan.
The winch-type sprinkler, which is driven by the hydrodynamic pressure inside the pipe, has the advantages of flexible maneuverability, adaptability to large and small fields, and low investment in equipment, compared to central pivot and translating large-scale sprinklers. At present, the investment per mu for imported equipment is about 50 yuan. After the localization of the equipment, the investment can be further reduced. This is a form of sprinkler irrigation suitable for China's national conditions and development prospects. It can be applied to field crops and vegetables. The winch-type sprinkler has two types of spray guns and folded racks. The latter has the advantages of good atomization and low energy consumption. Light and small unit sprinkler can be hand-lifted or mounted on a cart or tractor. It has the advantages of flexibility, adaptability, and low price. It is usually used for drought-resistant sprinkler irrigation on small plots. Each mu of investment is 100 yuan -200 yuan.
Micro-spraying is a new form of sprinkling irrigation. Micro-spraying is divided into hanging micro-spraying and micro-spraying. It is particularly suitable for use in agricultural greenhouses. It is more water-efficient and more evenly sprayed onto crops than general sprinkler irrigation. It transports water through PE plastic pipes and sprays them locally through microsprays. It can be expanded into an automatic control system. At the same time combined with the application of chemical fertilizers to improve fertilizer efficiency. A standard greenhouse micro-spray system equipment investment is generally around 800 yuan.
Drip irrigation is the use of plastic pipes to send water through holes or drips on a capillary tube approximately 16 mm in diameter to the root of the crop for local irrigation. It is the most effective water-saving irrigation method in arid and dry areas, and its water utilization rate can reach 95%. Drip irrigation has higher water-saving and yield-increasing effects than sprinkler irrigation, and it can combine fertilization and increase fertilizer efficiency by more than double. It can be applied to the irrigation of fruit trees, vegetables, cash crops and greenhouses. It can also be used for irrigation of field crops in drought-scarce areas. The disadvantage is that the dripper is susceptible to fouling and clogging, so the water source must be subjected to strict filtration. At present, domestically produced equipment has basically passed, and areas with conditions should actively develop drip irrigation.
According to the degree of fixed pipe, drip irrigation can be divided into three types: fixed, semi-fixed and mobile. For stationary drip irrigation, the location of pipes and drippers at all levels is fixed during the irrigation season. The advantages are simple operation, labor saving, time saving and good irrigation effect. Domestic investment in mu equipment is about 700 yuan (fruit trees) - 1400 yuan (shelf vegetables). For semi-fixed drip irrigation, the stem and branch pipes are fixed and the capillary tube is moved manually. Mu investment is 500-700 yuan. In mobile drip irrigation, dry, branch, and capillary tubes are all moved by hand. The equipment is simple, saving more investment than semi-fixed drip irrigation, but it has more labor. Mu investment is 2 yuan to 500 yuan.
The semi-fixed and mobile drip irrigation system researched and developed based on the specific conditions of China's large labor force and lack of funds has greatly reduced the construction cost, creating conditions for the promotion and application of drip irrigation in field crops and economically underdeveloped regions.
Storage drip irrigation is achieved through rainwater harvesting or by citing other surface runoff into water cellars (or other micro-impurity projects), or by using water storage tanks as a small mobile water source, coupled with drip irrigation to solve arid and dry areas. Farmland irrigation. It has the characteristics of simple structure, low cost, and can be adopted by every household. For the drought-poor mountainous areas, it is important to solve the food and clothing problem and develop courtyard economy for each farmer who has half a mu to one mu of farmland for drought and flood protection, and it should be vigorously promoted in drought- and water-scarce mountainous areas. Subsurface drip irrigation is the embedding of drip irrigation pipes into the underground active layer of root crops. Irrigation water penetrates into the soil through micropores for crop absorption. In some places, a small hole is drilled at a certain distance from the plastic pipe and buried near the roots of underground plants for irrigation. The people are commonly called "infiltration". Subsurface drip irrigation has the advantages of less evaporation loss, water saving, electricity saving, fertilizer saving, labor saving and significant yield increase benefits. Fruit trees, cotton, and food crops can all be used. The disadvantage is that 2, the irrigation water is not uniform enough when the distance between the pipelines is large, and it is not suitable to be used in places where the soil permeability is large or the slope of the ground is steep. Mu investment is 400-1000 yuan. The benefits are: saving 50%-60%; saving 40%-50%; increasing production by 30%.
Irrigation on membrane
The mulch covers the bottom of the ditch in the field. The introduced irrigation water flows over the mulch and penetrates through the small holes in the membrane to infiltrate the soil near the root of the crop. This method is called membrane irrigation and has been widely used in Xinjiang and other places. Promotion. Membrane irrigation, deep leakage and evaporation loss, water-saving significantly, on the basis of mulch cultivation does not need to increase the cost of materials, and can play a role in the soil warming and conservation. In arid regions, drip irrigation tubes can be placed under the membrane, or irrigation can be performed through capillary holes in the membrane. This is called submembranous irrigation. This irrigation method not only has the advantages of drip irrigation, but also has the advantages of mulching, and the effect of saving water and increasing production is better.
In areas where water resources are scarce in China, drip irrigation pipes can be placed under the membrane, or capillary tubes can be used for irrigation through small holes in the membrane. This is called drip irrigation under the membrane. This irrigation method not only has the advantages of drip irrigation (increasing the utilization of water), but also has the advantage of covering the plastic film (increasing the accumulated temperature), especially in the northern water-saving production increase.
According to the different demands of water for different growth periods of rice, "thin, shallow, wet, and sunny" control irrigation is carried out, which not only saves water, but also helps the growth of crops, changing the old habits of rice flood irrigation and string irrigation. It does not require additional investment in the project, as long as it is watered according to a water-saving irrigation system. "Thin, shallow, wet, and sunny" (thin rice seedlings, shallow water seedlings, early wetting of tillering, late sunning of tillering), and "drought of drought and cultivation and thinning" (drought cultivation of drought, rare planting, and proper replenishment) are all technologies A category has been widely promoted in more than 10 provinces and autonomous regions such as Guangxi and Jilin in recent years. In general, 100m3 of water can be saved per mu, and 25kg of rice can be added to increase yield. Rice water-saving irrigation technology has won the first prize of national scientific and technological progress and should be vigorously promoted in the rice area.
In areas with good economic conditions such as Jiangsu, Shanghai and Zhejiang, the laying of underground pipe systems for controlled irrigation and field drainage is conducive to saving water, fertilizer, and crops, creating favorable conditions for high yield, high efficiency, and high quality agriculture.
Sitting water species
In some places where water is scarce, spring sowing often fails due to spring drought or emergence. In order to preserve seedlings, mechanical or animal power tanks and water bags are used to pull water, and point irrigation is performed during sowing to solve the spring drought, commonly known as "sitting water species." This method is less investment, simple and easy, is an effective way to increase water production. When sowing, the water consumption per mu is only 5m3; -10m3;, the annual output of Fengshui can be increased by 10%-15%, and the drought year can increase production by 60%-70%. Sitting water species are currently widely used in Heilongjiang and Jilin, and where appropriate conditions should be actively promoted.
By leveling the land, we will improve the irrigation gully specifications (such as large tampers, small rakes, and long gulches to short ditch) and other comprehensive measures to make irrigation more uniform so as to save water.
According to the crop water requirement, timely and appropriate irrigation, advanced scientific and technical means to monitor the soil moisture content and the water conditions of the irrigation and distribution system of the irrigation area, data collection and computer processing, can scientifically and effectively control the soil moisture content, and carry out reasonable scheduling It is planned to use water and optimize water distribution so as to achieve both water saving and production increase. At the same time, it is necessary to attach importance to and strengthen water-saving management, change the current situation of low water prices for agricultural water, and unfavorable conditions for water conservation, and implement policies such as cost-based charges and over-planned water price increases. It is necessary to establish a sound water-saving management organization and technical extension service system and improve the rules and regulations for water-saving management.
The main technical details of water-saving irrigation in China are elaborated 2016-12-2 ±¾ÎÄ±»ÔÄ¶Á 604 ´Î