Irrigation technology refers to the use of artificial means to supplement water to crops such as farmland, orchards, and flowers. Its development process can be traced back to the ancient civilization period, passing through stages such as natural irrigation, water diversion irrigation, gravity irrigation, and pumping irrigation, and ultimately developing into modern irrigation technology. In the future, more digital irrigation technologies that fully utilize big data for intelligent decision-making will be applied to traditional irrigation projects in farmland water conservancy.
Development history of irrigation
The struggle for water is an extremely important chapter in the thousands of years of human civilization history. For example, the Zhengqu, Lingqu and Dujiangyan Irrigation Project canals in China, and the irrigation projects on both sides of the Nile River in Egypt with a long history are good examples.
In ancient times, about a few centuries ago, Middle Eastern farmers invented an effective method of irrigating trees in desert soil with the least amount of water. If water is poured directly onto the ground, a large amount of water will flow out of the plant and seep out to places beyond the reach of the roots. In order to control the water flow, farmers buried some special unglazed jars near the trees and regularly filled them with water. The water slowly penetrated through the clay wall, forming a wet soil around the tree. Trees planted using pot irrigation method grow well just like orchards irrigated with ditches. This is the ancestor of modern garden irrigation.
Before the 20th century, after centuries of exploration, humans learned the techniques of blocking rivers for water storage, building canals for water diversion, and opening borders for irrigation. However, low water efficiency limits the expansion of irrigation area. People are striving to produce enough food to provide food for the rapidly growing population, and how to improve water utilization has become a major challenge in the 21st century.
In 1871, J Lessler applied for the first patent for a water driven lawn sprinkler in the United States. Fixed spraying devices were quickly invented by rotating nozzles, rotating nozzle models, rocker nozzles, hoses, and nozzles.
In 1894, an Iowa native named Charles Skinner invented a very simple sprinkler system, pioneering the use of mechanical facilities for water-saving irrigation by humans. In the 20th century, nozzles were made of aluminum tubes, plastic, and rubber, and sprayed water in a parabolic shape. The adjustable swinging nozzle has a metal arm that can spray a fan shaped water curtain within a range of 600 square feet (55.7 square meters). The water rotates the spray arm of the sprinkler through an elliptical cam, while a gear set slows down the speed of the water to one mile per hour. In the 20th century, it became common for gardens to use sprinkler systems in private residences and public parks. At this time, due to their connection to the municipal water supply system, hoses could be used to connect to automatic sprinkler systems for irrigation. In 1933, a farmer named Otten Ingerhart from California, USA, invented the world's first rocker nozzle and registered a patent. The emergence of this new type of nozzle has played a revolutionary role in promoting water-saving irrigation in agriculture. After using the rocker arm sprinkler system, the water utilization rate is greatly improved, which can be increased by more than 50% compared to flood irrigation. In this way, the same amount of water can be applied to an additional 50% of the area.
After World War II, the economy and technology of the United States developed rapidly. Irrigation companies led by Pierce manufactured various quick connect aluminum alloy joints that were connected to thin-walled aluminum pipes, resulting in semi fixed and fixed thin-walled irrigation systems, making it possible to use irrigation systems on a large scale. The advantage of a semi fixed system is its low cost and no impact on field cultivation. The disadvantage is that manual handling is labor-intensive. The advantage of a fixed irrigation system is that it has low labor intensity but high cost, which has an impact on field cultivation and is suitable for irrigation of perennial plants.
In the 1950s, due to rapid economic development, labor costs in the United States rapidly increased. Farmers urgently need machines that have lower labor costs than rolling irrigation machines.
In 1952, a farmer named Frank from Colorado invented a hydraulically driven, self rotating, and sprinkler mounted irrigation machine called the Center Pivot. Later, the production rights of this machine were sold to the Valley Company in Nebraska (now Vimont). Its advantages are high automation program and very low irrigation labor cost; Strong terrain adaptability, no need for flat land. The disadvantage is low land use efficiency (approximately 78%). After the 1960s, this type of machine was widely promoted in the sparsely populated and uneven central agricultural areas of Colorado, Nebraska, and Kansas in the United States.
In the 1970s, due to the impact of the oil crisis, the nozzle of the central pivot irrigation machine was changed from a rocker arm nozzle to a low-pressure micro nozzle, in order to achieve the goal of energy conservation. Afterwards, hydraulic drive gradually changed to electric drive, with increasing reliability. Currently, about 31% of the total irrigation area in the United States is irrigated using a central pivot system. In order to improve land use efficiency, a lateral moving irrigation machine was later developed, but it was not widely used due to its high cost, inconvenient maintenance, and high energy consumption.
Although the water efficiency of irrigation is significantly higher than traditional surface irrigation techniques, it is still unsatisfactory for areas that are very dry and have little rain. Because irrigation requires full wetting, evaporation between plant seeds is essentially an ineffective water loss.
The predecessor of today's drip irrigation system appeared in the late 19th century, when Afghans conducted experiments using unglazed clay pipeline systems. In 1913, a study conducted by E.B. House at Colorado State University showed that slow irrigation could be applied directly to the root area of plants. In Germany in the 1920s, researchers designed controlled irrigation systems based on porous pipes, which were predecessors of modern drip irrigation technology. In the late 1940s, an Israeli agricultural engineer named Symcha Blass invented the drip irrigation technology in Britain. In the 1950s, he brought this technology back to the Negev Desert in Israel and applied it for irrigation in greenhouses. Since the early 1960s, drip irrigation has been widely promoted in Israel and California, mainly used for fruit and vegetable irrigation. The water efficiency of drip irrigation is over 90%, mainly due to no water loss. If managed well, there is no deep leakage, no surface runoff loss, and direct infiltration into the root zone makes the evaporation loss between plants very small. In addition to very high water efficiency, the use of drip irrigation systems for fertilization has a better effect. According to the fertilizer requirements of different growth stages of plants, different fertilizers can be accurately applied with irrigation water, which can enable plants to grow in the optimal water and fertilizer environment. After using water-soluble fertilizers, drip irrigation not only increases plant yield and saves water resources, but also greatly improves plant quality.
In the 20th century, irrigation and drip irrigation techniques were not only unprecedentedly developed in agriculture, but also widely used in courtyard landscaping. Lawn irrigation often uses buried irrigation technology, mainly for the purpose of landscaping.
Since the 1980s, many enterprises and researchers have begun to explore underground drip irrigation technology (SDI), maximizing the advantages of drip irrigation technology (without ground evaporation loss). SDI has also been applied to lawn irrigation, but there are few reports of achieving good results and its promotion is relatively slow.
China began developing fixed irrigation systems in some suburban vegetable fields in the early 1950s. In the early 1970s, small irrigation machines (artificial rainfall machines) and rotating nozzles were developed. In 1978, we completed the development and production of two series of products: rocker arm sprinkler and irrigation pump. We also developed light, small, medium, and large irrigation machines. Afterwards, we successfully developed full jet sprinkler and clockwise (circular), translational, winch, and rolling irrigation machines. At the same time, low-pressure sprinkler and micro sprinkler also appeared one after another. In the mid-1980s, irrigation and drip irrigation techniques were rapidly developed in China. After years of effort, many drip irrigation production lines have been introduced, digested, absorbed, and imitated. The product quality has made great progress compared to the 1980s. After the diligent exploration of predecessors in the last century, the utilization technology of irrigation water has reached a very high level. Entering the 21st century, irrigation technology has developed at an unprecedented speed. Many irrigation experts predict that irrigation in the 21st century will develop towards a highly automated and intelligent direction with lower energy consumption and cost, and higher efficiency.
The advantages of modern irrigation technology
Modern irrigation technology refers to the use of high-tech means, such as precise data collection and measurement, computer simulation and control systems, to achieve accurate control and management of farmland moisture. Its main characteristics and advantages are as follows:
1. High precision: Modern irrigation technology adopts advanced instruments and automation control systems, which can achieve precise control of parameters such as irrigation water volume, irrigation time, and irrigation frequency, thereby improving the accuracy and efficiency of irrigation. Provide accurate water supply based on crop water demand and soil moisture to avoid waste and water shortage.
2. Water conservation and energy conservation: Modern irrigation technology can accurately calculate the amount of water required for irrigation based on the water demand of crops and soil moisture conditions, avoiding the common phenomena of excessive irrigation and leakage in traditional irrigation methods, thus achieving the goal of water conservation and energy conservation. Modern irrigation technology can reduce the use of irrigation water through recycling and reuse.
3. Strong adaptability: Modern irrigation technology can adjust irrigation water volume and irrigation time according to different crop types and growth stages to meet the water and growth needs of different crops, thereby improving crop yield and quality.
4. High degree of automation: Modern irrigation technology adopts automated control systems, which can achieve automatic control and monitoring of the irrigation process, reducing farmers' labor intensity and improving work efficiency. The digital irrigation system can also achieve autonomous irrigation decision-making, saving more water and fertilizer usage for irrigation and fertilization.
5. Good environmental friendliness: Modern irrigation technology can avoid common environmental problems such as soil erosion and soil salinization in traditional irrigation methods, thereby protecting the ecological environment and achieving the goal of sustainable development.