In the previous articles (find it here), we looked at the basics of Hydroponics farming systems, its benefits, demerits and the basic operations of the system. In this second article, we will look at the various types of Hydroponics systems that prospective entrepreneurs can adopt using locally available materials.
1. Drip system
This is the most commonly adopted Hydroponics system. Adopting the system entails, first, mixing the nutrients required for the plant in a reservoir. Next, the pump incorporated into the system pumps the nutrient mix to the plants. The plants are usually grown in perforated pots and the pump will pump the nutrient solution via a tube to the root zone of the plant. The excess solution is released to the grow tray and back to the reservoir as shown in the image.
Farmers can control the flow rate of the pump using a timer to ensure it delivers the desired nutrients at an appropriate rate for subsequent uptake by the plant. Alternatively, the farmers can use drip irrigation emitters, which will discharge the nutrient solution at an appropriate discharge rate in the tubes, to allow different crops to be grown simultaneously with the same system. Regular checks of the quantity of nutrient solution in the reservoir is important when using this system to ensure that there is sufficient supply of the same to the root zone of the plants.
2. Ebb and Flow System
This method, also referred to as the Flood and Drain System, will have the farmer setting a timer to periodically activate the pump. When the pump starts, the nutrient solution will flood the grow tray, thereby supplying the plant with the required nutrients. The pump will then go off once the tray is sufficiently flooded and the excess solution will then flow back to the reservoir.
Compared to the previous methods, this approach is far much simpler as IT entails only flooding the grow tray and in the process, feeding the plant of the required nutrients.
3. Nutrient Film Technique (NFT)
Unlike the previous systems which rely on timers to determine the nutrient solution feed rate to the crop, this approach does not require a timer. Instead, the nutrient solution is continuously pumped into the grow trays and the excess solution flows back into the reservoir via gravity. Since this method is dependent on gravity, the grow tray is slanted at an angle as captured in the image below, to allow for natural gravitational flow of the solution.
It is advisable to include an air stone when using this system to ensure the water stays oxygenated.
4. Deep Water Culture (DWC)
In this system, the grow tray is not separated from the nutrient reservoir, as is the case with the previous methods. A piece of Styrofoam is put on the surface of the nutrient solution, allowing it to hold the plants firmly at the top. The containers holding the plant will usually have holes at the bottom to allow the roots of the plants to grow downwards into the nutrient solution. An Airstone incorporated into the system keeps the nutrient solution oxygenated.
Important to note is that water does not circulate in the system, as is the case with the previous ones. Thus, it is best suited for plants that require a lot of water such as lettuce. The roots of the plants will be submerged into the nutrient solution throughout the plants life
5. Wick system
This method uses a wick to deliver nutrient to the plants via the growing media, as shown below.
Notably, the nutrient uptake by the wick to the plant is slow, and as such, the method is not suitable for large plants that require a faster nutrient uptake. The method, however, works very well for smaller plants such as the ones shown below
The choice of the method to adopt depends on the plant and other contextual factors such as the available space, the target volume and the budget of the farmer. We advise that a prospective entrepreneur engages an expert on Hydroponics from the onset of the project to guide him/her on which method to adopt, together with the benefits and drawbacks of each alternative. In the next post, we will look at the important points to remember when engaging in hydroponics farming.