I have an interest in the future of food. By 2050 it is projected that 80% of people will live in an urban environment. I want to understand how we can produce food for this growing urban population.
On a recent trip to South-East Asia, I spent some time staying with friends in Singapore and took the opportunity to arrange a visit to Comcrop. The Mission and Vision of Comcrop fitted well with the kind of urban farming organisation I was looking to learn more about.
“We aim to build a sustainable business by connecting communities to healthy, locally produced food; taking care of our planet; and by making farming fun again.”
“We believe urban agriculture is the key to a sustainable city. Our vision is to create resilient, local ecosystems that produce fresh, flavorful food in cities to build stronger communities.”
I wanted to understand the challenges of doing urban farming on a roof-top location in Singapore. I went on a tour of Comcrop with Darren Tan, the Sales and Outreach Manager. The first thing to say is that the visit took place at 2 pm and the heat on the roof was intense! How and what can you grow on a roof in these types of conditions?
Hydroponics vs an aquaponic system?
The answer to how you grow in these conditions is by using a hydroponic, vertical farm. Hydroponics is a system that uses water with nutrients added to it. There is no soil involved. This nutrient rich solution is then pumped around the towers and feeds the roots of the crops. The roots take up the nutrient rich solution and grow. At Comcrop solar energy is used to power the pumps and the system recycles between 70-90% of the water used for growing. There are information boards available to explain the process and why this is a sustainable approach.
Comcrop had tried aquaponics. Aquaponics is a combination of aquaculture (farming fish) and hydroponics (growing plants in water with added nutrients rather than soil). Aquaponics uses the nutrients in fish poo to feed the plants. However, the decision was taken to convert to hydroponics. This was for two main reasons. The first was that the nutrients from the waste produced by the fish had too many nitrates for the crops they were growing, so they still needed to supplement the water. Plants need the right balance and mix of nitrogen, phosphorous and potassium to grow well. When these three elements are present in the wrong proportions, it causes growth issues for the plants. The second reason for switching to hydroponics was that the fish did not grow at the same rate as the nutrient requirements of the plants.
What does Comcrop Grow?
Darren showed us the main crops that were currently being cultivated in the vertical towers. These included sweet basil, peppermint, a small amount of spearmint and wasabi greens.
We tasted the basil, peppermint and spearmint which all had an intense flavour. I had wondered whether using hydroponics would affect the taste of the crop: it does not. The basil is able to cycle through a couple of times before it needs to be replanted.
Darren explained that they also grow lettuce. Up to 500 plants which spend two weeks at the seeding stage and then require a further 4 weeks to produce a full head of lettuce. The lettuce is grown in the top two rows of the hydroponic system.
Darren explained that the plants need lots of time for acclimatisation on the roof-top environment. They test new crops firstly for the heat and secondly to see if they like being grown hydroponically! The temperature on the roof-top is 2 or 3 degrees hotter than at ground level. And a roof is not a controlled environment, so pests are an issue and have to be monitored. For example, tomatoes are no longer grown because they suffered from tomato blight.
Some plants currently being cultivated in a variety of pots on the roof include pandan and lemongrass, ochre, rosemary, wood sorrel, butterfly pea and chillies. The key for successful growing is to work with needs of the individual plants. For example, the rosemary and ochre, have clay pellets added to the pots. These pellets help the roots of the plants gain stability and to grow strong plants. Rosemary is a herb that would not grow hydroponically because it does not like its root system to be damp. For the potted plants, a drip irrigation system is used to ensure efficient use of the water resources.
Fascinating Fact: The blue flowers from the butterfly pea can be used to make tea, colour desserts and create blue rice. The blue is the blue used for blue litmus paper, so if you drop lemon juice into the butterfly pea tea, the tea will turn red due to the acid in the lemon juice.
Comcrop has paid staff to grow and sell its produce. They sell to an online grocer, and local bars and restaurants. This creates a sustainable business. With the business side taken care of, Comcrop is able to offer volunteering opportunities through community engagement schemes.
As a volunteer involved with a couple of community projects where I live, I was interested to hear how Comcrop engages with the wider community in Singapore. Darren explained how anyone from the community is able to come along and make a meaningful contribution to the growing and harvesting process. Comcrop also has a partnership with MIND (Movement for the Intellectually Disabled of Singapore) training people how to germinate plants.
Comcrop also works with schools, and it was heartening to hear that the emphasis is on helping students understand the growing process as a first step. I think this is the way to really connect people with food and plants. Once someone has mastered what growing is then the focus can shift to the different ways in which growing food is possible.
I would like to thank Darren for his time and willingness to answer questions. Comcrop offers private tours, like ours, for a small fee or offers a free tour on the first Saturday of the month. And look out for news of how and Comcrop is planning to expand its operations.
The way we grow food for people in urban areas is going to develop and expand over the coming years. Although it is not clear which combination of growing techniques will be most efficient urban farms, such as Comcrop, are pioneers in using and testing these different models in a tropical climate.
Singapore currently imports the vast majority of its food. So urban farms that use space-saving techniques such as vertical farming can make an important contribution to food growing in the future.