Various ways to do agriculture without soil - a listing
How to farm without soil
- The story: "Soilless Cultivation" refers to any method of growing plants without soil as a rooting medium. To ensure global food security to meet the demands under uncertainty as COVID-19 pandemic and increasing population, food production must rise by 60% by 2050. The natural prerequisites of agriculture, namely arable land and water, have been depleting with rapid urbanization across the globe. To feed the increasing population, not only does the productivity of food crops need to be increased in the existing arable land, but alternative farming techniques need to also be encouraged.
- Types: There are some key types
- Hydroponics - It is a method of growing plants in a water-based, nutrient-rich solution. Here, the root system is supported using an inert medium such as perlite, clay pellets, peat moss or vermiculite. The purpose is to provide access to oxygen which is essential for proper growth. The hydroponic farming technology with closed water loop systems is a viable option for farmers with limited access to land and water. Its significance increases many folds when it comes to urban and peri-urban areas where the arable land is polluted. Lower and more efficient resource consumption allows this alternative farming technique to be adopted by a variety of stakeholders According to the Food and Agricultural Organisation (FAO), the vegetable yield of soilless systems is 20-25% higher than in traditional systems as the number of plants per square metre is higher. But the problem is that the water needs to be replaced at regular intervals as standing or recirculating water makes it easier for plant disease to spread if pathogens enter the water supply. Water and electricity are the two major factors in Hydroponic farming, in absence of adequate water supply or stable electricity, the Hydroponic system won’t thrive well.
- Aeroponics - It is an environment-friendly way of farming in which the roots are suspended in the air and plants grow in a humid environment without soil. It is a variation of hydroponics where both growing medium and flowing water are absent. The roots of the plants, in this method, are sprayed with water and nutrient solution. This enables farmers to control humidity, temperature, pH levels and water conductivity inside a greenhouse. The water usage in the system reduces by 98% and fertiliser usage by 60%. Pesticides are fully eliminated as the absence of soil reduces chances of diseases. The aeroponically grown plants can be harvested three times faster and the yields are more consistent. As nutrients are sprayed onto the plants and roots, there's plenty of oxygen and other gases in the growing chamber for roots to absorb. Farming in a confined space gives the farmer control over pest and locust attacks and sudden heat waves. But the problem is Aeroponics is far too dependent on technology. If any component of the system fails or breaks, it would render the entire system completely useless. One has to be able to set up and run the Aeroponic System and also be able to create the perfect nutrient solution for the plants otherwise the plant might die. Aeroponics is highly costly and hence not affordable for everyone, setting up such a system can cost around Rs. 8 crore per hectare. The plants must receive constant attention to their pH levels and nutrient density ratio as there is no growing medium available to do this work.
- Aquaponics - It is a system that combines hydroponics and aquaculture within a closed system. There are three biological components in the aquaponics process: fishes, plants, and bacteria. The system represents a symbiotic relationship between the plants and the fishes; the fish feces is used as fertilizer for the plants, and the plants clean the water for the fish. Two agricultural products (fish and vegetables) are produced from one nitrogen source (fish food). Such a system also prevents aquaculture waste from polluting nearby watersheds. It doesn’t involve pesticides or herbicides as these chemicals may kill fish, and the fish feces is the nutrient-rich fertilizer for the plants. Aquaponics can result in huge water savings contrasted with a garden grown on the ground (80-90℅ water savings). An aquaponics system can be set on any scale, as small as an aquarium and as big as a greenhouse commercial farm. But the supporting ideal environments for both plants and fishes make aquaponics a more complicated endeavor than hydroponics. It is not suitable for tuberous plants and root vegetables as they perform most of their growth within soil and aquaponics uses water as a substitute for soil. In aquaponics, the conditions where the system can fail are more; the fish can die if they do not have the right conditions and the plants are also susceptible to pathogens.
- Improving food production: Strengthening food production and distribution systems is key to fighting hunger and tackling the burden of malnutrition. The development of aquaponics and hydroponics embrace all dimensions of food security. The government can consider these as alternatives for traditional farming and provide assistance in making these techniques affordable to a larger number of farmers.
- Knowledge: While these techniques can be utilized by a variety of stakeholders, from household farmers and small- to large-scale farmers, specific knowledge and skills must be developed for safe, successful and sustainable implementation. In a country like India, there is a constant pressure on agricultural land and its conversion to other uses. With Aeroponics and Hydroponics, the discussions around farming can move away from land constraints to focussing more on sustainable farming techniques.