Soilless culture technology is suitable for gardening enthusiasts of different levels. The DIY soilless system not only saves money, but also helps growers build vegetable gardens that meet their personal needs and aesthetics.
What is soilless culture
Simply put, soilless cultivation means growing crops without soil. Most people think that the growth of plants is inseparable from the soil, which is not the case. We can use other substrate materials to replace the various functions of the soil. First of all, the soil can support the growth of plants, assist the roots in fixing the plants, and at the same time provide a growth environment for the roots of the plants, moisturizing and heat preservation. Without the fixing effect of the soil, tall trees will not be able to stay upright in the wind. However, soilless cultivation can use various cultivation substrates and cultivation racks to replace soil to fix plants. Second, the soil can provide the necessary nutrients for plant growth. But in the same way, soilless plants can obtain water-soluble nutrients needed for growth from organic solid fertilizers or nutrient solutions. In addition, the microorganisms in the soil can interact favorably with the root system, and these microorganisms can also survive and multiply in the soilless culture system. Therefore, when building a home garden, we can replace soil cultivation with soilless cultivation.
Advantages of soilless culture
Not restricted by land conditions
It is generally believed that only those lucky ones with large tracts of land can engage in gardening. Soilless cultivation technology provides opportunities for those who have no land or no suitable arable land to own a family garden. The combination of soilless cultivation and facility gardening can help garden enthusiasts build a home vegetable garden in every corner of the home.
Strong crop growth
In soil cultivation, there are always some limiting factors that hinder the growth of crops and cannot maximize their growth potential. Plant roots sometimes need to find nutrients. This is because soil nutrients are always uneven in spatial distribution, and there is organic matter that cannot be effectively used by roots because they are not decomposed by organisms, and some nutrients are fixed in soil particles and cannot be used by plants. The above reasons Will lead to plant nutrient deficiency. In addition, too much or too little water will restrict plant growth. Excessive water can cause hypoxia in the root system and hinder the root system from absorbing water and nutrients. The combination of soilless cultivation and facility gardening can cultivate crops in nutrient solutions and provide them with accurate and reasonable nutrients, water and oxygen conditions, which can give full play to the growth potential of crops.
In soil cultivation, plants need to continuously extend and expand the root system to obtain the water and nutrients needed for growth. Soilless cultivation reduces the need for plant roots to find water and nutrients, and the growth space of plants is no longer restricted by the size of the root system, but only by the size of the canopy.
Not subject to seasonal restrictions
Obviously, indoor planting can extend the growing season. In addition, even in the outdoors, soilless cultivation can clearly extend the growing season. Compared with leaf temperature, root temperature has a greater impact on plant growth and development. If the root temperature can be kept within the optimal temperature range of 18.3-23.9°C (65-75°F), cool-loving crops can also be grown in an environment of 37.8°C (100°F); in cold climates, it can also be increased Plant temperature-loving crops at the temperature of the root zone. Soilless cultivation improves the ability to precisely regulate the temperature of the root zone. Growers can use heaters and coolers, or simpler methods (such as building liquid storage tanks), to increase or decrease water temperature to promote crop growth.
Not restricted by natural conditions
Soilless cultivation gives new life to poor soil. Soilless cultivation can be used to produce food in many areas on the earth that are not suitable for crop growth due to bad weather or lack of water resources. Soilless cultivation creates opportunities for desert cultivation. The climatic conditions of the desert are very suitable for the growth of crops. Not only are there enough light and fewer pests, but the lack of water resources restricts the development of its agriculture. Soilless cultivation techniques with less water consumption provide the possibility to build desert farms. Soilless culture is also the main method for planting plants in the space station, and this technology has been successfully used to produce a variety of plants (such as lettuce) on the space station.
Save water resources
Soilless cultivation can recycle the nutrient solution and effectively save water resources. In soil cultivation, most of the water is lost due to evaporation and infiltration, while in soilless cultivation, the nutrient solution is recycled after recovery, and evaporation is greatly weakened or even eliminated due to the closedness of the system.
No need to weed
At first glance, weeding seems to be a minor problem. But for traditional soil growers who have weeding experience, most people are more willing to do other more interesting things, such as preparing a big meal to celebrate the harvest. Soilless growers do not need to weed, nor buy herbicides, nor do they need to worry about the potential damage to crops caused by the flow of herbicides, that is, they do not have to worry that the wind will blow herbicides from other places and damage or even wither the crops.
Reduce the use of pesticides
Soilless vegetable gardens outdoors and in greenhouses may also be infested by pests, but the incidence of pests is greatly reduced. Because pests usually hide in the soil or rotting plant debris, it is difficult for them to find hiding places in soilless vegetable gardens. The pest control technology combining soilless culture and facility gardening can effectively prevent pests in vegetable gardens.
Reduce nutrient loss
The amount of fertilizer used in traditional farming is difficult to control. First, the weather is uncontrollable, and the heavy rain after fertilization may wash away most of the nutrients; secondly, daily irrigation may also take away the nutrients in the soil. Advanced soilless culture technology can achieve “zero loss” of nutrients. However, it requires the grower to test the moisture and chemical composition in the nutrient solution, and to fully understand the special nutrient requirements of the crop. It is more suitable for growers with a certain professional background and foundation (horticultural industry practitioners). Soilless culture enthusiasts need to replace the nutrient solution in the soilless culture system every few weeks to avoid nutrient deficiency in crops due to the imbalance of nutrient solution nutrients. Plants consume different nutrients at different rates, so over time, some nutrients will accumulate and some will be deficient. Regularly changing the nutrient solution can ensure that the crop gets a balanced nutrient. These waste nutrient solutions will not be wasted and can be used to water outdoor vegetable gardens or potted plants. Therefore, the traditional soil cultivation vegetable garden and the soilless cultivation vegetable garden can coexist very well.
The most common misunderstanding of soilless cultivation is: because soilless cultivation crops grow in water, the density of the nutrient solution of agricultural products produced (usually refers to the amount of important nutrients such as vitamins, minerals, and proteins contained in foods based on unit calories) Concentration.) Lower than the product grown in the soil. Many studies have shown that there is no difference in the nutrient density of soilless and soil-grown crops. There are many factors that affect the nutrient density of crops. For example, fertilizers will affect the nutrient content of crops, but environmental factors have a more significant impact, which will greatly affect the absorption and utilization of nutrients by crops. Light intensity and light quality, as well as water stress caused by irrigation, will affect the content of antioxidants, and temperature will affect the amount of sugar. There are many factors that affect the nutrient composition of crops, but in general, vegetables are rich in nutrients, the difference is small, and the taste is basically not affected. If the nutrient density of the crop is significantly different from the normal value, it will generally show obvious nutrient deficiency. Therefore, no matter what the growth environment is, as long as the plants look normal to the naked eye, their nutrient status will not be much different.
Nevertheless, soilless growers still develop some unique methods to regulate the nutritional content of crops. In many commercial soilless tomato production, increasing the level of nutrient supply at the critical time of tomato development can induce an increase in tomato sugar content. In order to ensure the normal growth of tomatoes, growers will first increase the level of nutrient supply, induce an increase in sugar, and then reduce the nutrient supply to a normal level. Oizumi Yasaikobo of Chichibu City, Japan has developed a low-potassium lettuce soilless culture technology. These special lettuce are specially provided for patients with kidney disease who cannot consume high-potassium vegetables because of dialysis treatment. There are many similar examples all over the world. The production of special crops according to consumer needs fully reflects the ability of growers to precisely control the growth environment of crops.
Crop growth characteristics controllable
In addition to nutrients, the combination of soilless culture and facility gardening can also adjust crop leaf size, leaf color, root size, plant height and other growth characteristics. Growers can regulate plant growth patterns through light quality. For example, using blue light can make plants grow more compact and reduce the crop’s need for vertical space.
Clean and hygienic
The soil cultivation environment is relatively messy, although it is not a disadvantage, it also limits its application in the family. For example, if soil cultivation is used in the International Space Station, soil particles suspended in the air can cause damage to sensitive equipment. In the space station, the biggest advantage of using soilless cultivation to grow crops is clean and hygienic, and the crops basically do not need to be cleaned after harvest. In addition, soilless culture can keep the indoor environment tidy and avoid muddy, so that children can touch plants cleanly in the classroom or at home. The bed-type soilless cultivation floating vegetable garden is one of the most suitable soilless vegetable gardens for children.
Easy operation and low labor intensity
Compared with traditional soil cultivation, soilless cultivation is easier, easy to fertilize, easy to automate, and does not require weeding. Beginners may find soilless cultivation very complicated, but after planting one or two batches of crops with this technique, they will fall in love with this cultivation method.
Good controllability and repeatability
Practice is the best teacher. Soilless crops grow rapidly and have a short growth cycle, which helps growers quickly accumulate experience in a limited time. At the same time, soilless planting experience is easy to replicate and promote. Once someone finds a planting method suitable for the current environment and crops, others can easily repeat the process. In addition, soilless culture technology allows growers to accurately repeat irrigation frequency and fertilizer supply levels. Combined with facility gardening technology, growers can further strengthen the management of crops. The annual production of the same crop is achieved by repeating environmental factors such as light intensity, light time, temperature, humidity, carbon dioxide level，and airflow, without being affected by seasonal and inter-annual changes.
Prevent soil-borne diseases such as root rot and bacterial wilt
Some highly infectious plant pathogens can be spread through the soil. Any soil cultivation grower who has experienced root rot or bacterial wilt knows that it is very difficult to eradicate this problem. These pathogens live in the soil, and when the conditions are right, they attack plants and cause disease. Soilless cultivation can fundamentally avoid the occurrence and spread of soil-borne diseases. Once a pathogen is found, the next crop can be planted as long as the crops and cultivation facilities are cleaned, washed and disinfected.
Avoid contamination of agricultural products
In traditional agricultural production, animal manure is a major organic fertilizer. If not properly treated before application, potentially harmful pathogens (including Escherichia coli, Listeria, and Salmonella) may even cause a large area of food-borne diseases. In actual production, there is often uncontrollable application of manure organic fertilizer, such as manure pollution from wild animals, which makes farmers a headache. In 2011, an E. coli disease broke out in Oregon, the United States. Investigations revealed that the disease was caused by wild deer dung. Soilless culture systems are often in a controllable non-wild environment, and it is difficult to produce feces, avoiding the pollution of feces from wild animals. Another potential source of pollution in traditional soil cultivation is heavy metals in soil or water. Studies have shown that crops replanted in heavy metal-contaminated soil or water sources can absorb heavy metals and cause heavy metal poisoning of crops. It is very difficult to remove heavy metals in the soil, but soilless growers can use filtration methods to easily reduce the heavy metal content in the water.
The main components of the soilless culture system
The soilless culture system is actually very simple. First of all, a liquid storage tank that can store nutrient solution and is impermeable is needed. Sometimes plants can be directly planted in the liquid storage tank. Secondly, a cultivation bed is needed to place the plants. The size and type of the cultivation bed determine the types and yields of plants grown. Usually, you also need to install fill light and ventilation system. Finally, a cultivation substrate is needed, which can store and release nutrients for plant root growth.
Most soilless culture systems require a liquid storage tank to store nutrient solution (a mixture of fertilizer and water), and there are many options for fertilizer sources. The nutrient solution is suitable for a variety of plants and can also meet the needs of special crops. Giving right and wrong to soilless plants is as easy as brewing iced tea powder. First, mix the powder or concentrated liquid, then stir, and you are done! It is also very easy to make a liquid storage tank. It can be a plastic bottle or a glass bottle, it can be a transformed common household item (such as a storage box), it can also be built with wood and plastic cloth, or it can be purchased directly.
The adjustable cultivation bed in the soilless cultivation system is suitable for all plants. Soilless growers can create optimal growth conditions for crops through irrigation frequency, flower pot and tray size, cultivation substrate and environmental conditions. However, the practicality of soilless culture varies from crop to crop. Although it is feasible to grow wheat and corn with soilless cultivation system, the economic benefits are low. Because they often need a large area of land to ensure sufficient pollination, soilless cultivation, as a high-density planting method, cannot effectively increase its economic value. However, the use of soilless cultivation system to grow vegetables and flowers has advantages that traditional soil cultivation cannot match. Among all the soilless cultivation systems introduced, the biggest difference lies in the design of the cultivation bed. For example, the waste liquid from the cultivation bed in the circulating soilless culture system will return to the liquid storage tank. Compared with traditional soil cultivation, the recycling of nutrient solution in soilless cultivation system can greatly reduce the water needed for crop growth.
Soilless cultivation crops grow fast and produce high yields. The soilless culture system combined with the facility gardening technology hardly requires the application of herbicides and pesticides. Because there is no soil and the amount of pesticides used is low, soilless crops are usually cleaner than soil. Some agricultural products (such as lettuce) consume more water than their growing water during cleaning. Therefore, soilless cultivation can not only reduce the water consumption for crop growth, but also effectively reduce the water required for cleaning agricultural products.
Traditional soil cultivation and soilless cultivation have their own advantages. Simply saying that one method is better than the other may attract investors’ interest in one of them, but doing so will make people ignore the fact that the two methods have their own characteristics.
The fertilizer used in soilless cultivation systems is very different from traditional soil cultivation. Soilless cultivation fertilizers need to provide all the nutrients needed for the normal growth of plants, while the soil only needs to use the main nutrients required by a few plants, because there are already many nutrients in the soil. Therefore, it is possible to use soilless cultivation fertilizers in the soil, but it is not feasible to use soilless cultivation fertilizers in soilless cultivation systems. The first is because soil fertilizers cannot contain all the oxygen needed for plant growth, and more importantly, because they may pollute the water in the soilless culture system. For example, the manure that is often used in traditional soil cultivation cannot be used in soilless cultivation systems. If animal-derived fertilizers such as blood meal, bone meal, fish meal and feather meal are used in soilless cultivation systems, unpleasant odors will be produced in the cultivation system. The biggest advantage of traditional soil cultivation is that these animal-derived fertilizers (usually a by-product of the meat industry) can be used to grow plants and avoid waste in landfills.
Most soilless fertilizers, including chemical fertilizers, are obtained from mined minerals and their products by consuming large amounts of energy. For example, the Haberbers ammonia production method converts atmospheric nitrogen into ammonia, which can be used to produce urea and ammonium nitrate. Modern agriculture relies heavily on mining and synthetic fertilizers. About general nitrogen fertilizer comes from chemical processes, and the crops that these fertilizers nourish feed billions of people.
Chemical fertilizers and organic fertilizers each have their own advantages and disadvantages. Looking at one aspect alone, one of them may have a huge advantage, but if you compare all aspects, the situation is much more complicated. The synthesis process of chemical fertilizers emits a lot of carbon, but it is smaller than organic fertilizers and facilitates transportation. Chemical fertilizers are clean and have accurate nutrient content, making them suitable for soilless cultivation. Compared with traditional soil cultivation, the use of chemical fertilizers can avoid waste water and save a lot of water resources. These pros and cons continue to prove to us that no method is perfect. Therefore, it is necessary to learn various planting methods by reference, and to combine their advantages to create a sustainable planting model.