Can Plants be grown without Soil?
If I say plants can grow without soil, would you agree with me? It seems to be impossible, doesn’t it? But it is actually quite possible; plants can grow without soil. A common example of this is: Money plant in a bottle or lotus plant in a pond.
You may see that in many houses people grow money plants in a bottle or a glass jar and this adds to the décor of their home. But, how is this possible? In this case, a vase or glass pot gives support to the plant and the water provides minerals as nutrients. Also, plants get the required oxygen, temperature, moisture from its surroundings. Thus, these plants can grow in the given condition.
Sometimes, you may have noticed, that plants are growing on concrete wall and on rocks. Also, some plants grow on other plants, these are called parasites.
Now, from the above mentioned example we can say that, plants can grow without soil. But, the question is, how? From where do they get nutrients if there is no soil?
Let’s discuss this.
You may know that soil simply provides minerals to the plant and gives support to it; the soil itself is not necessary for the growth of the plants. To us, this is a totally a new concept.
We know that the main conditions for the survival of plants, animals, human being are nutrients, water and light. So wherever they grow they must get their required nutrition, water and light properly, in the right quantity. Now if we can design such a circumstance where plants will have all the required things in the water supplied to the plant, then, it will be possible to grow plants without soil.
Scientists have developed such a method to grow plants in the absence of soil. This method is known as ‘Hydroponics’. Let’s see what this method is, how does this work?
Hydroponics: In short, this is a method of growing plants without soil. In 1929, William Geirek, of California University, created a sensation among people by producing a huge tomato vine in mineral nutrient solution without soil. He is the person who introduced the term Hydroponics. The word ‘hydroponic’ means ‘water culture’.
In this method, roots of a plant are brought into contact with water, containing mineral nutrients. Nutrients in this method may be: by-product of fish waste, duck manure or may be normal nutrients and roots can be supported by gravels, perlite or coconut husk etc. These gravels, perlite, coconut husk, all act as a growing medium. This is a simple explanation of hydroponic system.
In this system a container is needed to place the plants in. This is called a grow tray. Nowadays, most of the containers for hydroponics are made up of plastics. Other materials, like concrete,, glass, metal, wood etc., are also used to make these containers.
Large hydroponic farms use vast network of plastic pipes. These plastic pipes have holes to place the plants in, and through these pipes, there is a continuous supply of mineral nutrients mixed with water, to the plant roots. This is a common method of hydroponic system.
There are different types of the hydroponic system. Let’s discuss these systems one by one.
In this system, plants are placed in a separate container. They don’t have any direct contact with the reservoir, containing nutrient mix water. Some wicks or string are used to supply the nutrient mix water from reservoir to the roots in the grow tray where roots grow. Wicks or strings are made up of absorbent material like cotton or sponge. One end of the wick or string is fit inside the grow tray and another side is hung down inside nutrient mix water. Nutrients mixed in water is absorbed by the wicks or strings and reaches up to the grow tray where roots are growing. This upward movement of water through thin tubes, strings, or wicks is known as capillary action. Pump is not used in this system.
Deep water culture
In this system, roots are totally under the nutrient mix water. An air pump is used to pass air through this water so that roots get sufficient oxygen from air. Lettuce plant can grow well in this system.
Ebb and flow system
In this system roots get nutrients mixed in water at regular intervals. This system requires a water pump and timer. With the help of water pump, roots are flooded by water, but at specific intervals and this water, drain back to the reservoir again for reusing. The pump is connected to the timer so that this process can repeat itself.
In this system, a water pump with a timer is needed. Nutrient mix water will be dripped on plants by drip nozzles, these drip nozzles are connected with water pump. In this system excess water is collected in the reservoir so that this can be reused.
NFT system (Nutrient Film Technique): In this system, roots of plants are getting continuous flow of nutrient mix water and this flow of water is being collected again in the reservoir and it is used again. A water pump is needed to create a continuous flow of water.
Aeroponics is an efficient means of growing plants in air or in mist environment and of course without soil. It is just like indoor gardening. In this method plants are put in a frame or horizontal board in such a way that its roots and stem and leaves hang in the air so that they can get required oxygen from air. In this way tops of the plant grow upwards and roots grow downwards. And also in this method roots are regularly nourished by spraying water and mineral solution and we don’t need to immerse the roots in any solution or water. In this system, the containers in which roots are growing are to be sealed, light proof and almost airtight. It does need to allow some fresh air for required oxygen and environment should be pest free. As the container is enclosed, nutrient mix water is re cycled inside the container and thus solution is saved in the aeroponic system. This is a well-controlled method.
NASA did some experiment with this method. They successfully grew Asian bean seedling in Mir space station.
There are always some advantages and disadvantages of each and every system. But, with the advancement of technology we can try this as home gardening, especially if the soil is not good enough for gardening. Also, as it is soil-less gardening you can avoid dirt.
Thus, we see that the system of Hydroponic cultivation, though useful, is not as effective as the practice of growing plants in the soil. This process is most useful when growing herbs, or plants inside the house for the purpose of decoration.