Irrigated lands around the world occupy about 19% of the cultivated area, but provide as much agricultural products as non-irrigated ones. Irrigated agriculture accounts for 40% of world food production and 60% of cereal production.
Irrigated agriculture has historically been an alternative to traditional crop production, which directly depends on the soil and climatic conditions of the region and meteorological factors. Irrigation (or irrigation) is the main type of reclamation measures, which consists in creating and maintaining such a water regime of the soil, which is necessary for plants to grow and mature.
Thanks to artificial irrigation, it is possible to cultivate crops that naturally lack moisture, to organize sowing in arid areas in such a way as to obtain guaranteed high and stable yields.
The yield of agricultural crops grown in irrigation agriculture (such as wheat, rice, sugar beets, etc.) is 2-5 times higher than the results of traditional crop production. In combination with irrigation, technologies of repeated and compacted sowing are used. This allows you to use the land productively, collecting up to 3 crops per year from the fields. Experts say that irrigated farming increases the profitability of an agricultural business from 12% to 20%.
Irrigated agriculture in our country
The origins of water management in Russia are associated with the reign of Peter I. And the first domestic state institution in charge of issues of watering land, as well as problems of drainage of swamps, was created at the end of the 19th century by the Department of Land Improvement of the Ministry of Agriculture. As a result of the ongoing work on the regulation of water intake from rivers and the construction of wells, 3.8 million hectares of land were irrigated in Russia.
Land reclamation, which had been suspended in connection with the revolutionary events of 1917, was resumed by the Soviet state during the first five-year plans. By 1941, the area of irrigated land was 11.8 million hectares. In the post-war years, the destroyed hydraulic structures were intensively restored. The great achievement of the Soviet period was the construction of unique irrigation and drainage systems. These are the Volga-Don and Kuban-Yegorlyk canals, hydraulic structures of the Barybinsk steppe in Western Siberia, and the Saratov irrigation canal. The main suppliers of moisture to the fields were such waterways as the Bolshoi Stavropol and North Crimean canals.
The peak of achievements in domestic irrigation falls on 1985, when about 20 million hectares were irrigated in the country. By the beginning of the 90s, the area of reclamation lands accounted for almost 10% of the total arable land. But the collapse of the USSR and the land reform carried out in those years had a negative impact on the formation of the reclamation complex. Work on the creation of hydraulic structures was practically stopped. The reduction to 4.5 million hectares of the area under irrigation agriculture was critical.
According to experts, in order to ensure food security of our country, the minimum area of irrigated land should be at around 10 million hectares. That is why the Ministry of Agriculture of the Russian Federation, based on the developments of the All-Russian Research Institute of Hydraulic Engineering and Land Reclamation, created the state program "Fertility", which was in effect until 2013. Then it was replaced by a new federal targeted state program "Meliration", designed for the period until 2020. The purpose of the current measures is to ensure the necessary increase in irrigated land, as well as to reduce by 20% water consumption for the needs of irrigated agriculture.
The relevance of irrigation is obvious, since a shortage of precipitation in Russia is observed in 80% of all arable land. The main areas of irrigated land are concentrated in the arid regions of the country: the Lower and Middle Volga regions, the Trans-Volga region, the North Caucasus and Krasnodar Territory, the Crimean Peninsula, Western and Southern Siberia, Transbaikalia and the Far East.
- The traditional regions of irrigation agriculture include Saratov, Volgograd, Astrakhan regions, Tatarstan and Kalmykia. Dry summers have been and remain the norm here.
- Farming in the North Caucasus and Krasnodar Territory is unthinkable without irrigation due to the insignificant amount of precipitation falling there.
- Irrigation of the Crimean steppe zone is relevant today in connection with the problems of water intake from the North Crimean canal.
- In addition, vegetable, fruit, fodder crops, meadows and pastures in areas that have not previously experienced drought require irrigation. These are the Altai Territory, the Central Black Earth Region and some territories of the Non-Black Earth Region.
According to statistics, today in Russia, reclaimed land accounts for 8% of the total arable land. And they give about 15% of the gross production of goods. About 70% of vegetables, 100% of rice, more than 20% of fodder crops are produced using the irrigation system of agriculture. Under irrigation, they grow mainly cereals (wheat, corn, millet, rice, etc.), legumes, industrial crops (sunflower, cotton, etc.), vegetables, fruit, as well as various types of coarse and succulent fodder.
Hydraulic systems in irrigated agriculture can be classified according to the type of openness and the method of irrigation. In open systems, water is supplied through canals, trenches and trays. Systems that use piping are called closed systems.
Depending on the method of supplying water for irrigation (by ground, underground or by air), all irrigation systems are divided into groups.
For surface wetting, so-called furrow irrigation, a simple method of pumping water through ditches, trenches or pipelines is used.
The water supplied in this way to the fields is retained by means of valves. This irrigation system is used, as a rule, in small areas where exclusively moisture-loving crops are planted. The distribution of water in the ditches between the rows is required for sugar beets and vegetables. Rice is grown by flooding the area. The disadvantages of this irrigation technique include high water consumption.
Humidification of large areas is carried out using mobile irrigation units. At the heart of such a device is a drum mounted on a tractor, on which a flexible hose is wound. Driving across the field, the tractor lays out a pipeline into which water is pumped with the help of a pump. Watering is carried out through outlets made in the pipeline at a distance of about 20 m from each other.
Due to the simplicity and mobility of the system, this type of irrigation is quite common in modern crop production.
The most efficient and economical irrigation machines for crops such as alfalfa, corn, grapes are sprinklers.
The design is based on a truss, which most often has the form of a triangle. Water supply to the unit is carried out using a water intake device called a "frog". Irrigation using self-propelled and non-self-propelled systems of a circular or frontal type is called "sprinkling".
- The principle of root irrigation consists in spraying water from specially laid underground or above-ground perforated pipes. Irrigation from stationary pipelines directly moisturizes the root system of plants. Drip irrigation systems significantly save water and are used for watering vegetables (in particular, tomatoes and cucumbers), as well as melons and gourds.
- Humidification of the surface atmospheric layer with the smallest drops of water is called aerosol irrigation. By adjusting the temperature and humidity, you can create comfortable conditions for plants to grow and develop.
- Aerosol irrigation is widely used in orchards, citrus groves and vineyards. This type of finely dispersed irrigation is convenient to use in areas with difficult terrain.
Gardening today is carried out using a high-tech method of growing plants in artificial environments without soil, called hydroponics. All the plants need are obtained from the nutrient solution that surrounds the roots. This gives good results and significantly reduces water consumption.
Thus, the type of irrigation devices and structures used depends on the type of crops grown. Vineyards, corn fields cannot do without sprinkling. For pastures and grasses, natural irrigation methods are acceptable. Rare watering is sufficient for cereals and forage crops. Irrigation methods with an optimized water consumption are recognized as the most effective for orchards and vegetable gardens.
The use of this or that form of irrigation agriculture depends on the natural zone in which it is carried out. After all, the characteristics of water sources, and the organization of water intake, and the size of the canals on the plains, in the foothills or in mountainous terrain are significantly different. Therefore, for each zone, a specific configuration of the irrigation network, the most suitable water regulating devices, etc.
- In flat areas, large flood irrigation systems are most often used, and flood floods are embanked.
- In the valleys of large rivers, irrigation is carried out using dams and dams. Often it is combined with the methods of rainfed sowing of spring crops on spring-winter precipitation.
- One-time spring deep soil moistening on floods of rivers and streams of local runoff is called estuary irrigation or swamp farming.
- In mountainous areas, terraced irrigation systems are used, in which complex artificial hydraulic devices are used.
But whatever zonal form of irrigation agriculture is used, irrigation is based on the principle of metered water supply. After all, any plant is harmed by both a lack of moisture and its excess.
Agriculture is the most significant consumer of fresh water reserves. World agriculture annually consumes more than 2, 8 thousand cubic meters of water. Almost the entire volume is used for irrigation of 290 million hectares of land. This is 7 times more than the water consumption of the entire world industry. Sources of moisture required for the cultivation of crops are surface or groundwater. For irrigation in the dry season, the water of rivers, lakes and streams accumulated in reservoirs or artificial lakes is used. Wells are built for the intake of groundwater. In coastal areas, water for fields is obtained by desalination. However, water scarcity in many countries is a factor limiting the development of irrigated agriculture.
The approximate amount of water used only for cultivation (not including processing or preparation) of food crops, which one person consumes daily, is about 17 liters.
The average consumption of water by different crops to obtain high yields is characterized by very impressive figures.
Therefore, in addition to choosing the optimal technology for the cultivation of irrigated plants, the tasks facing irrigation agriculture include the use of economical methods of spending water resources.