Agriculture is proliferating, and we are seeing new and exciting ways to farm emerging amongst innovative practitioners. One area that is ripe for innovation is in the vertical space. People in cities, informal settlements and on top of roofs and in small yards and spaces are pushing the boundaries of agriculture. Bags filled with soil and compost can be purposed to grow food and they can hang off the ceiling so rats and vermin do not eat the crops. They can be stacked on top of each other. I believe there is a really good opportunity here for a creative and innovative seamstress to manufacture bags that are good for growing plants. The design of such a bag could include a receptacle at the bottom to keep water as growing in a bag quickly drains a bag of water. This is a real good opportunity for a new enterprise. Old “streepsak” or poly-fibre bags can be repurposed to enable the growing of crops in confined spaces. There is simply no shortage of opportunities in this regard!
The pressures of farming in confined spaces could lead to great innovation. On the 23rd of March 2019 we hosted Ayanda Booi at the iZindaba Zokudla Farmers’ Lab (https://www.facebook.com/permalink.php?story_fbid=660481277705370&id=100012305107081) who developed a complete insect farming system in Diepsloot, Johannesburg. She was able to eat and sell her produce, at times for significant amounts. This shows what is possible! Vertical farming is a call to seize new opportunities to farm in new ways!
Vertical farming is a collective term that refers to farming in a confined space, with crops and or livestock organized in vertical as opposed to open air and on-the-ground systems for production. This could simply mean you build a trap to collect chicken manure below the chicken coop, or you organize a more elaborate system with plants on top and fish- or aquaponics, at the bottom. Vertical farming could also refer to stacking or hanging bags above raised beds so you make use of space most efficiently. When you water the bag, you also water the bed!
A really good illustration of vertical farming would be African Women in Agriculture’s Veronica Aswani’s Ama-veggie Pyramid. Please see: https://www.facebook.com/Amaveggies-116473306778840/. This is a simple system that reorganizes a heap of soil into a more productive system. This is more productive as the Ama-veggie pyramid is easier to manage, harvest from, water and plant than a mere “heap” of soil. The crops are all in one place, it can be taken care of much easier. This may be a really good opportunity for those with very little land. Land in this case is manufactured by compost-rich soils stacked vertically. Those who are considering this alternative, note that you could construct similar systems with bags, pieces of wood or any other material. A good farmer would build one before she buys one!
A lucrative off-shoot off vertical farming is to build a grow tower. This is a stacked tower, from barrels, boxes, bags or even bent sheets of metal, plastic or wood, with a pipe placed in the middle. The pipe is drilled with holes and earthworms are placed in the pipe. Feed the pipe and worms with food waste and they then drag this fertilizer to the tower itself. Take a look at how simple this may be: https://za.pinterest.com/pin/454933999840996542/.
A lucrative and productive alternative to vertical soil-based farming would be hydroponic farming. Thendo Ratshitanga from Rooftop Roots is a proficient manufacturer of such hydroponic systems. Hydroponics means we are farming in liquid or water (“hydro”) and the key characteristic is that plants do not grow in soil but in a salt-rich watery medium that is often pumped and recirculated in the system. Typically, hydroponic farmers buy two kinds of salts (often in large bags that can last for more than a year) and these are mixed right before watering the plants. You simply water the plants 2/3 times a day in the bags. The salts are enough for the plants and plants grow very quickly in this way, with the first harvest possible after 2 weeks. The liquid can be used over and over again until the salts are depleted. The salts also last long in the bag and can also be re-sold.
The cheapest and most cost-effective system I have ever seen was at the Abraham Kriel Emdeni Farmers in Xuma Street Soweto. They construct hydroponic systems with black bags as containers (but use any container larger than 20 liters). These bags are filled with rough river sand (available in rivers or at the curb in your local street) with seedlings planted in them. These bags are placed in simple tunnels made with shade cloth and PVC electrical conduit pipes. Harvests are large! There is very little standing between a farmer and the opportunity to build a system like this.
Hydroponics however are appropriate to implement at large scale. Large scale systems are expensive and can cost up to R 10 000 a meter. Such designed systems are very productive, and often use “Nutrient Film Technologies” which is a fancy word for ripples on the inside of the pipes etc. where nutrients accumulate and are thus easily taken up by roots. If you are a large farmer, and have access to large markets, it would be best to adopt an off-the-shelf designed system, as a large scale system would include the most efficient technology and this would be necessary to recover the costs of the system.
However, “home-made” or “repurposed” gutters are almost as effective and may be a more profitable proposition. Smaller systems, for say 100 square meters of space, can be constructed by re-purposing gutters and sewerage pipes and there are many examples of these on YouTube. This is perhaps the most important opportunity available and those with some space and access to markets should consider a system like this. It would be important to experiment with a DIY system like this before buying an off-the-shelf designed system.
Aquaponics is a step “up” from hydroponics. Aquaponics however, do not often use additional chemicals and “salts” like hydroponics and nutrients as the nutrients that plants need are derived from the manure given by fish or other animals in the system. Aquaponics thus integrates fish or animals with crops. The water, laden with nutrients from the fish, is recycled and given to plants which remove the volatile nutrients and cleans the water. The water from the fish is also treated before it is given to plants, mostly by blowing compressed air through it, to change the nitrites or ammonia to nitrates which plants can use to grow.
Aquaponic systems are complex. However, INMED has built an aquaponics demonstration farm in Soweto that is used to teach people this production technique. Please see the following: https://inmed.org.za/aquaponics/. The systems are simple and strong and are designed for households and implementation in the backyard. However, these systems can be expanded and currently more than 40% of all our seafood is already farmed in this way. Technology has progressed and there are many examples of these systems available. We will be listening to Unathi Sihlahla from Soweto on the Soweto Aquaponics systems.
The above systems can all be constructed at home in a DIY way. Aquaponics, for instance, also includes farming fish in a pond and using crop and animal residue as feed for the fish. It does not need a complicated pump and one can easily move the crop residues to the pond by hand. Earthworms can feed such fish and can be easily grown for the fish. A good farmer farms with information and I believe merely by identifying these opportunities, we can inspire some to take them up.
Hydroponics is also open to improvisation and it may be, after we calculate all costs, that a simple hydroponic system using salts and black bags or any found container, is more profitable than a store-bought setup. Farmers need to make these choices for themselves! These alternatives need to be researched by farmers and these systems are open to improvisation and innovation. A vertical farm could be a chicken coop placed above crops, so the farmer does not have to labor to move manure to soils, as gravity does this for free. Hydroponics could be a simple black bag with river sand, or a complicated system of pipes linked to pumps. Aquaponics could be a simple pond with fish that you feed with food scraps and earthworms. These technologies are open to use and innovation and please join us at iZindaba Zokudla on the 14th of May at 13h00 on Facebook for this event. Please look out for my next Blog post where I send the link!
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