Chapters 2.16
2.16 - Sand Hydroponics for Mini-Tuber Seed Potatoes
Callie Leszek, University of Guelph,Canada
Related video(s): Managing seed potato (Source: Access Agriculture)
https://www.accessagriculture.org/managing-seed-potato?cat_id=1499
Suggested citation for this chapter.
Leszek,C. (2025) Sand Hydroponics for Mini-Tuber Seed Potatoes . In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph,Canada. http://www.farmpedia.org
Challenges for Mini-Tuber Seed Potato Production Within Sub Saharan Africa
In Sub Saharan Africa, potatoes (Solanum tuberosum, also known as Irish potatoes in Africa) are an excellent source of vitamins and minerals and if using the right systems, can be grown amply and affordably. However, the current potato yields within sub–Saharan Africa are low, at approximately 6-10 t/ha (Lemaga et al. 2015). This can be compared to the 2023 potato yields in Canada which are 37.35 tons/ha (Government of Canada, 2023). Potatoes are propagated by farmers, not through seeds, but from pieces of tuber. By propagating potatoes vegetatively from tuber pieces, there is a higher chance that disease from one potato can spread to others (African Farming, 2024). There are also risks with the associated soil being used. An example of a disease that can grow due to unbalanced soil is Common Scab, which harms potatoes grown in soil with a pH above 5.5 (African Farming, 2024). To overcome these risks, ‘mini-tubers’ (i.e. mini potatoes) can be bred for multiple generations in indoor environments without soil (i.e. disease free conditions) and used to multiply ‘seed potatoes’, which are also mini-tubers but used by farmers for planting in the field. If these can be grown more efficiently, potatoes may be the pathway out of poverty for potato farmers in Sub Saharan Africa, due to the high yielding capabilities and quick growth of potato. This chapter explains a new mini-tuber-seed potato propagation method known as sand hydroponics.
The Current Advanced Method Used Has Challenges
One of the current advanced methods of mini-tuber seed potato production used in Sub Saharan Africa is based on aeroponics – where roots grow in the air (Figures 1 and 2). In this system, potato plants (post in vitro stage) are hung within a box often made of styrofoam; inside the box is a constant flow of water droplets (that are pressurized into a fine mist) and a dense nutrient solution containing the fertilizers (Sharma et al., 2016). This system requires a constant stream of water throughout the growing season, and with that, constant electricity to operate the box. If the power stops, it can create irreversible damage to the growing potatoes. Thus, the lack of consistency in electricity access impacts crop growth (Lemaga et al. 2015). In addition, the system requires frequent maintenance that can be quite costly. There are many intricate parts of the system that can break, such as the metal spray jets that control the droplet size, or the mineralization transducers. Overall, the reliance on stable electricity makes aeroponics a risky choice for small scale farmers in Sub Saharan Africa (Sharma et al. 2016).
A New Method: Sand Hydroponics for Mini-Tuber Seed Potato Production
An alternative to produce seed potato mini tubers is called sand hydroponics, which is a low cost and low disease risk method in which the tubers are propagated in pathogen-free sand instead of soil or attempting to grow roots in the air. This method is shown in Figure 3:
How can sand hydroponics be adopted? Starting with potato plantlets grown in vitro in test tubes from a supplier, you should immediately place them in an environment with sufficient lighting, as they often are in a very dark environment during the transportation time from the supplier. It is important to give them time to acclimatize before being placed in sand (Otazu, 2010). It is crucial that the sand being used is uncontaminated (river sand is often chemically contaminated so try a few different sources near you to find the best option). It is important to wash the sand multiple times prior to sterilizing (Otazu, 2010). The next step is to boil sand with water for 30 minutes at 70 degrees Celsius. After the boiling is complete, transfer the sand to plastic trays (or plastic lined crates), filling them about 5-7 centimetres deep. Then keep the sand in a humid environment (enough that poked holes stay held during the transplant phase). Prior to the transplant into sand, you can open the test tubes and expose the plants to the humidity of the greenhouse (but be mindful to avoid direct sunlight). Now it is time to transplant the plants into the small holes made in the sand. During the first five to seven days in the sand, they should be watered with a 1:1 mix of nutrients solution and water; after those days it can switch to a full-strength fertilizer solution (Otazu, 2010).
Benefits of Sand Hydroponics to Produce Mini-Tuber Seed Potatoes
One of the many benefits to sand hydroponics is the lack of reliance on electricity and running water, which makes it a much more dependable way to grow potatoes. Another benefit is that sand hydroponics is an operation to waste system that allows for nutrient solutions to recycle, reducing the likelihood for disease and reducing input costs (Thiele, et al. 2022). Any small step towards reducing disease allows for more potato growth and a successful starter crop. Another benefit is the use of gravity which allows for important nutrients to distribute evenly while the sand can substitute for conventional substrates. This means that sand hydroponics also does not require substrate sterilization as the sand is treated instead with boiling water, reducing cost and electricity reliance (Thiele, et al. 2022).
Previous Recorded Outcomes
Featured is a graph highlighting potato production productivity in Kenya, Uganda, and Ethiopia between the years of 1986 and 2006, utilizing non hydroponic systems. It is evident in the graph that productivity has remained rather stagnant throughout those years other than a few small up and down spikes (FAOSTAT, 2007). As the food demand rises throughout the world with an increase in population, it is crucial that food production productivity increases with it (FAO, 2014)
Cost of Implementation
Below are the start-up costs for a sand hydroponics system. The items listed are available on Alibaba.com at the prices in this breakdown:
--Crates are $112 USD for 50 sized 600 x 400 x 120 mm.
--500 square feet of waterproof plastic lining comes to $132 USD.
--A small greenhouse is $127.79 USD.
--Sand can be sourced locally from uncontaminated sources.
--These quantities/costs can be scaled up or down depending on individual needs. The estimated total cost is $372.52 USD, not including operation costs.
In comparison to the cost of the hydroponic set up, here is a cost breakdown of an aeroponic module (16 m x 5 m greenhouse):
-Tank and plumbing supplies add up to $684.8 USD.
-The boxes add up to $1778.4 USD.
-The electrical equipment and supplies add up to $3767 USD.
Therefore, the total set up cost of an aeroponic system $6230.2 USD. (Otazu, 2010)
Critical Analysis
Based on all the information presented, it is evident that each method of mini-tuber potato production has different positives and negatives. When looking at a common competitor to hydroponics, which is aeroponics, the lack of dependability due to inconsistent power and electricity access is a concern (Sharma et al. 2016), as already noted. It is difficult to predict the crop outcome when one power outage could impact the whole growing season. However, sand hydroponics requires reliable and consistent water access to sterilize the sand, ensure disease does not strike, and to water the plants, which is a risk factor as well. When it comes to cost, sand hydroponics can be operated at a much lower cost, which is a great benefit; however, it is a much more manual process as it requires the farmer to water the plants and track their progress (Thiele, et al. 2022). This is in comparison to the aeroponic system which is self-sufficient due to its misting system, but repairs can be difficult and expense. However, aeroponic systems are much more industrial and allow for long term use, whereas sand hydroponics are constructed locally, making it less sturdy, but simpler to repair.
Conclusion
Sand hydroponics has the capacity to be a great solution to assist small scale and commercial farmers to improve access to disease-free potatoes, particularly in Sub-Saharan Africa due to its lack of dependence on consistent electricity. It is evident that the alternative methods, like aeroponics, work well or even better in some cases, but in places without consistent water and electricity access, sand hydroponics is a good alternative. Improving potato production in Sub-Saharan Africa is a crucial step to overcoming food insecurity, and having a more accessible way to grow seed potatoes is a pivotal part in that.
Practical Links to Get Started
1.Manual on quality seed potato production using aeroponics (CGIAR): https://doi.org/10.4160/9789290603924
2.YouTube video on mini-tuber production using aeroponics:
https://www.youtube.com/watch?v=wPlQV9FhmqA
3.Further reading on sand hydroponics versus aeroponics:
4. Reading on mini-tubers in Africa (CGIAR:
4. Short video on sand hydroponics: https://www.google.com/search?q=sand+hydroponics+potatoes+CGIAR&rlz=1C5CHFA_enCA993CA993&oq=sand+hydroponics+potatoes+CGIAR&gs_lcrp=EgZjaHJvbWUyBggAEEUYOTIHCAEQIRigATIHCAIQIRiPAjIHCAMQIRiPAtIBCTEwMjEzajBqNKgCALACAQ&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:c54f9eb9,vid:7i_yztPkVng,st:0
References
Çalişkan, M. E., Bakhsh, A., & Jabran, K. (2023). Potato production worldwide. Academic Press. https://shop.elsevier.com/books/potato-production-worldwide/caliskan/978-0-12-822925-5
Gildemacher, P. R., Kaguongo, W., Ortiz, O., Tesfaye, A., Woldegiorgis, G., Wagoire, W. W., Kakuhenzire, R., Kinyae, P. M., Nyongesa, M., Struik, P. C., & Leeuwis, C. (2009). Improving potato production in Kenya, Uganda and Ethiopia: A system diagnosis. Potato Research, 52(2), 173–205. https://doi.org/10.1007/s11540-009-9127-4
Buckseth, T., Sharma, A. K., Pandey, K. K., Singh, B. P., & Muthuraj, R. (2016). Methods of pre-basic seed potato production with special reference to Aeroponics—a review. Scientia Horticulturae, 204, 79–87. https://doi.org/10.1016/j.scienta.2016.03.041
Demo, P., Lemaga, B., Kakuhenzire, R., Schulz, S., Borus, D., Barker, I., Woldegiorgis, G., Parker, M. L., & Schulte-Geldermann, E. (2015). Strategies to improve seed potato quality and supply in sub-Saharan africa: Experience from interventions in five countries. Potato and Sweetpotato in Africa: Transforming the Value Chains for Food and Nutrition Security, 155–167. https://doi.org/10.1079/9781780644202.0155
Tessema, L., & Dagne, Z. (2018). Aeroponics and sand hydroponics: Alternative technologies for pre-basic seed potato production in Ethiopia. Open Agriculture, 3(1), 444–450. https://doi.org/10.1515/opag-2018-0049
Thiele, G., Friedmann, M., Campos, H. A., Polar, V., & Bentley, J. W. (2022). Root, tuber and banana food system innovations: Value creation for inclusive outcomes. Springer. https://link.springer.com/book/10.1007/978-3-030-92022-7
Devaux, A., Kromann, P., & Ortiz, O. (2014). Potato research. Springer. https://link.springer.com/journal/11540
Otazu, V. (2010). Manual on Quality Seed Potato Production Using Aeroponics. International Potato Center (CIP) https://doi.org/10.4160/9789290603924
Canada, A. and A.-F. (2024, December 9). Government of Canada. Agriculture and Agri-Food Canada. https://agriculture.canada.ca/en/sector/horticulture/reports/potato-market-information-review-2023-2024#a-1
Potato production – diseases and Pest Control - African farming. (n.d.). https://www.africanfarming.com/2024/09/27/potato-production-diseases-and-pest-control/