Soilless cultivation

irrigation part is consist of one completed system to provide water and fertilizer to the plants in the greenhouse

Soilless cultivation refers to a cultivation method in which water, peat or forest leaf mulch, vermiculite and other media are used as the substrate for the root system of the plant to fix the plant, and the root system of the plant can directly contact the nutrient solution. The composition of nutrient solution in soilless culture is easy to control and can be adjusted at any time. In places where the light and temperature are suitable but there is no soil, such as deserts, beaches, and deserted islands, as long as there is a certain amount of fresh water supply, it can be carried out. Soilless cultivation is divided into hydroponics, mist (air) cultivation and substrate cultivation according to different cultivation media. Hydroponics refers to the cultivation method in which the plant roots are directly in contact with the nutrient solution without using a substrate. The earliest hydroponics was to immerse the plant root system in the nutrient solution to grow. This method will cause hypoxia, and in severe cases, the root system will die. The hydroponic method of the nutrient liquid film method is often used, that is, a very thin layer of nutrient solution, which continuously circulates through the root system of the crops, which not only ensures the continuous supply of water and nutrients to the crops, but also continuously supplies fresh oxygen to the roots.
Soilless cultivation is a new technology of crop cultivation developed in recent decades. Crops are not cultivated in soil, but are planted in an aqueous solution (nutrient solution) containing dissolved minerals; or in some kind of cultivation medium, crops are cultivated with nutrient solution. As long as there are certain cultivation equipment and certain management measures, crops can grow normally and achieve high yields. Because it does not use natural soil, but uses nutrient solution to irrigate crops, it is called soilless cultivation.
The characteristic of soilless cultivation is to replace the soil environment with the artificially created root growth environment of crops. It can not only meet the needs of crops for nutrients, water, air and other conditions, but also control and adjust these conditions to promote better growth of crops. , and obtain a better balance between vegetative growth and reproductive growth. Therefore, crops grown without soil usually grow and develop well, with high yield and high quality.
In the middle of the 19th century, German scientist Van Leibig established the prototype of mineral nutrition theory, which laid the theoretical foundation for modern soilless cultivation technology. Sachs and Knop successfully planted plants in nutrient solution around 1860, established the method of cultivating plants with mineral nutrient solution that has been used to this day, and gradually evolved into modern soilless cultivation technology. In 1929, Gericke in the United States carried out large-scale soilless cultivation research, and used nutrient solution to grow tomatoes up to 7.5m in height, and harvested 14kg of fruit per plant. In the 1940s, as a new cultivation method, soilless cultivation was successively used in agricultural production. Many countries have successively established soilless cultivation bases, and some have also built greenhouses. During the Second World War, the British Air Force used soilless cultivation methods to produce vegetables in the Iraqi desert and the United States on Wake Island in the Pacific Ocean to supply wartime needs. Later, different countries began to apply the technology of soilless cultivation and achieved greater development. In 1955, during the 14th International Horticultural Conference held in the Netherlands, some soilless cultivation researchers initiated the establishment of the International Soilless Cultivation Group (IWOSC), which was renamed the Soilless Cultivation Society (ISOSC) in 1980.
The research and production application of soilless cultivation in my country began in the 1970s, mainly for soilless seedling raising of rice and soilless seedling raising of vegetable crops. In 1980, a cooperative group for industrialized seedling cultivation of vegetables was established nationwide. In addition to research on soilless seedling cultivation, research on soilless cultivation techniques in protected areas was also carried out. In 2016, the Institute of Botany, Chinese Academy of Sciences and Fujian San'an Group established the world's largest artificial light plant factory, Zhongke San'an Plant Factory, realizing the large-scale industrial application of soilless vegetable cultivation.
1. Water-saving, fertilizer-saving, high-yield: various nutrients required by crops in soilless cultivation are artificially formulated into nutrient solutions for application, with less water loss, balanced nutrients, high absorption efficiency, and are based on crop types and the same Different growth stages of crops supply nutrients scientifically. Therefore, the crops grow and develop robustly, with strong growth potential, and can fully exert their potential for increasing production.
2. Clean, hygienic and pollution-free: organic fertilizers are applied in soil cultivation, and the fertilizers are decomposed and fermented, which will produce odor and pollute the environment. It will also breed the eggs of many pests and endanger crops. However, soilless cultivation uses inorganic fertilizers, which do not have these problems. And can avoid the pollution of harmful substances such as heavy metals in the polluted soil.
3. Labor-saving and labor-saving, easy to manage: soilless cultivation does not require intertillage, plowing, weeding and other operations, saving labor and labor. Watering and topdressing are solved at the same time, and the liquid supply system is regularly and quantitatively supplied, which is convenient for management, does not cause waste, and greatly reduces labor intensity.
4. Avoid continuous cropping obstacles: In the field planting management of vegetables, rational land rotation and avoiding continuous cropping are one of the important measures to prevent the serious occurrence and spread of diseases. The soilless cultivation, especially the hydroponics, can fundamentally solve this problem.
5. Not restricted by region, make full use of space: Soilless cultivation makes crops completely separated from the soil environment, and is not restricted by soil quality and water conservancy conditions. Many deserts, wastelands or areas that are difficult to cultivate on the earth can adopt soilless cultivation methods Take advantage of it. Getting rid of the constraints of land, soilless cultivation can also be free from space constraints. Using the flat roofs of abandoned factories and buildings in the city to grow vegetables and flowers has virtually expanded the cultivation area.
6. Conducive to the realization of agricultural modernization: Soilless cultivation frees agricultural production from the constraints of the natural environment and can be produced according to human will, so it is a controlled agricultural production method. Farming according to quantitative indicators to a greater extent is conducive to the realization of mechanization and automation, and thus gradually moving towards industrialized production methods
(1) For vegetable cultivation: to cultivate pollution-free green food, which is healthy and safe, and is deeply valued by people.
(2) For flower cultivation
Both cut flowers and potted flowers are suitable for soilless cultivation. The flowers cultivated without soil not only have large flower heads, but also bright colors.
(3) For the cultivation of medicinal plants
Many medicinal plants are root plants, and the growth environment of roots is very critical. Soilless cultivation can provide a good growth environment for medicinal plants, so the planting effect is very obvious.
(4) For fruit tree cultivation
Fruit tree rootstock seedlings cultivated by soilless culture grow fast and have a high survival rate; fruit trees that are rapidly propagated by cuttings take root quickly and have a high seedling rate.
(5) Used for soilless seedling cultivation
The seedlings of soilless cultivation grow rapidly, the seedling age is short, the root system is well developed, strong and tidy, the seedling time is short after planting, and it is easy to survive. It can also avoid soil-borne diseases and pests caused by soil seedling cultivation, and it is also convenient for scientific and standardized management.
In addition, soilless cultivation can be used to grow vegetables and flowers on the roof balconies of cities without land to regulate life and beautify the environment. The development of soilless cultivation of vegetables can solve or alleviate the problem of food supply.
There are many types and methods of soilless cultivation, so that it is difficult to classify them in detail. They can only be divided into two categories: substrateless cultivation and substrate cultivation according to their fixing methods.
(1) Substrate-free cultivation
The characteristic of substrate-free cultivation is that the cultivated crops do not have a substrate to fix the root system, and the root system is directly in contact with the nutrient solution. Substrate-free cultivation is divided into two types: hydroponics and aeroponics.
1. Hydroponics: Hydroponics refers to a cultivation method that does not use a substrate to fix the root system, so that the plant root system is directly in contact with the nutrient solution. It mainly includes deep flow technique (DFT), nutrient film technique (NFT) and floating capillary hydroponics (floating capillary hydroponics
1) Deep liquid flow cultivation technology: The nutrient solution layer is deep, and the root system extends in the deep liquid layer. Each plant occupies a large amount of liquid, so the concentration of nutrient solution, dissolved oxygen, pH, temperature and water storage are not easy to occur. The drastic changes provide a more stable growth environment for the root system.
2) Nutrient liquid film technology: It is a hydroponic method in which plants are planted in a shallow flowing nutrient solution. Due to the shallow liquid layer, part of the crop root system is immersed in the shallow flowing nutrient solution, and the other part is exposed to the moisture in the planting tank, which can better solve the problem of root oxygen demand, but due to the small amount of liquid, it is easy to Affected by ambient temperature, fine management is required.
3) Floating plate capillary cultivation technology: adopt the root separation technology of floating plate wet felt in the cultivation bed, create an oxygen-rich environment for the cultivation of moist roots, and solve the contradiction between water and air; use a long horizontal cultivation bed to store a large amount of nutrient solution, It effectively overcomes the shortcomings of NFT. The environmental conditions of the crop rhizosphere are stable, the liquid temperature changes little, and the supply of nutrient solution is not afraid of being affected by temporary power outages.
2. Aeroponics: Aeroponics, also known as aeroponics or aeroponics, uses the filtered nutrient solution to pass through the atomization spray device under pressure to atomize the nutrient solution into fine droplets and spray it directly onto the A soilless cultivation technique in which plant roots provide the water and nutrients needed for plant growth. Aeroponics is the best form of solving the water-air contradiction of the root system among all soilless cultivation techniques, which can double the crop yield, and is also easy to automate control and three-dimensional cultivation, improving the utilization rate of greenhouse space. But it has extremely high requirements on the device, which greatly limits its popularization and utilization.
The characteristic of matrix culture is that the roots of cultivated crops are fixed by matrix. It fixes the roots of crops in organic or inorganic substrates. Organic substrates include peat, rice husk, bark, etc., and inorganic substrates such as vermiculite, perlite, rock wool, ceramsite, gravel, and sponge soil can all be used. As a supporting medium, supply crop nutrient solution through drip irrigation or trickle irrigation. In most cases of matrix cultivation, water, fertilizer, and air are coordinated, the supply is sufficient, the investment in equipment is low, it is convenient to obtain materials locally, and the production performance is excellent and stable; The treatment of residual roots is time-consuming and labor-intensive, and it is difficult
The core of soilless cultivation is to use nutrient solution instead of soil to provide the mineral nutrients needed for plant growth. Therefore, in soilless cultivation technology, whether it can provide plants with a nutrient solution with a coordinated proportion and an appropriate concentration is the key to successful cultivation. . Nutrient solution is the only source of plant root nutrition in soilless culture, which should contain all mineral nutrients necessary for crop growth, namely nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg ), sulfur (S) and other macroelements and iron (Fe), manganese (Mn), boron (B), zinc (Zn), copper (Cu), molybdenum (Mo) and other trace elements. Different crops and varieties, and different growth stages of the same crop, have great differences in the actual needs of various nutrient elements. Therefore, when choosing a nutrient solution, you must first understand the requirements of various types of essential elements for different varieties and growth stages, and use this as a basis to determine the composition and proportion of the nutrient solution. On the one hand, it should be based on the actual needs of the crops for various nutrients, and on the other hand, the fertilizer absorption characteristics of the crops should also be considered.
Soilless cultivation classic nutrient solution
1. Hoagland's hydroponic nutrient solution: Hoagland's hydroponic nutrient solution was published by Hoagland and his research partners in 1933 after a large number of comparative experiments. This is the most primitive but still in use A classic recipe.
2. Steiner nutrient solution: Steiner nutrient solution finally determines the ratio and concentration of various nutrient elements in the formula through the chemical balance between nutrient elements. It is widely used internationally and is suitable for general crops of soilless cultivation.
3. Japanese garden test universal nutrient solution: The Japanese garden test general nutrient solution was developed by the Japanese Xingjin Horticultural Experimental Field. It is suitable for a variety of vegetable crops, so it is called a general formula.
4. Japanese Yamazaki nutrient solution: The formula of Japanese Yamazaki nutrient solution is based on the determination of the absorption concentration of nutrient elements of various vegetable crops by Yamazaki Kenya from 1966 to 1976 to formulate a nutrient solution formula suitable for a variety of different crops.