Rows of Curly Kale
Written by Inky Ip and Food Made Good Team in collaboration with Sustenir
This August, our team visited Sustenir Agriculture’s incredible indoor vertical-hydroponic farm in Hong Kong.
Agri-tech start-up, Sustenir Agriculture has demonstrated that non-native crops can be grown locally, all-year-round, regardless of an unfavourable climate or space constraints. Today, they offer freshly-harvested leafy greens daily to major retailers such as Wellcome and Marketplace by Jasons.
“Nourishing people and the planet, one leaf at a time,” is the company’s mission and they perfected their recipe in Singapore, then replanted it in Hong Kong in 2020. By sensibly utilizing building space, vegetables can be grown in a way that matches the demands of a densely populated city.
Our Food Made Good team member visiting Sustenir Farm in Tuen Mun
Strictly adhering to the latest Controlled Environment Agriculture (CEA) techniques, farmers and visitors must wear PPE and undergo decontamination before entering the farm. This is to ensure that all produce is safe and hygienic. The reduction of dust and outside elements to the urban farm allows for 100% clean, pesticide-free crops to be grown, maximising freshness and nutrition.
As the tour began, it took time for our eyes to adjust to the violet-pink lights in the grow rooms that are critical for plant growth. Wavelengths of between 400 and 700 nanometers provide the right amount of energy needs for each stage of the plant’s growth. The ratio between green and red lights is precisely modified to maximise the plant’s growth in clean indoor rooms.
The success of Sustenir’s abundant harvests also relies heavily on precise environmental controls to optimise the room conditions that affect plant growth. Consistent monitoring of key conditions such as electrical conductivity and pH value provides plants with the right environments for them to thrive in.
Within the 25,000 square feet space, they grow a variety of vegetables which are often referred to as “Superfoods”: Curly Kale, Toscano Kale and Green Oakleaf. All these have high nutritional content such as fiber and vitamin A, C, and K. This is especially true of kale, which is among the planet’s most nutrient-dense foods. A single cup of raw kale provides two times more Vitamin C than an orange, strengthening your immune system. According to the Sustenir team, it also provides two times the daily Vitamin A and six times the daily value of Vitamin K.
Salad with Green Oak Leaf Lettuce from Sustenir
What is hydroponic farming?
In the absence of soil, water goes to work providing nutrients and oxygen directly to the roots. In hydroponic systems, the roots of plants are completely submerged in liquid and the nutrients which are essential to the plant’s growth are administered into the water via liquid solutions. The liquid solution contains an assortment of macro and micronutrients, such as nitrogen, phosphorus, and potassium. Due to these advantages, hydroponics is the predominant growing system used in urban farming settings. Vertical hydroponic farming is a fantastic way to grow an abundance of fresh vegetables within a limited space.
What makes hydroponic, urban farming sustainable?
Compared to conventional farming techniques which are primary outdoor soil-based systems, hydroponic farming reduces water usage by up to 95% and fertiliser use by up to 85%. Sustenir’s local farm in Tuen Mun greatly reduces the carbon emissions generated from air-freight or shipping. Reducing the carbon footprint generated from transportation is essential for our import-dependent metropolis, as Hong Kong continues pushing to be a more sustainable city. Urban and hydroponic farming can contribute to developing a more self-sufficient city by creating new sources of stable and plentiful vegetables grown close by.
Why does Sustenir grow so much kale?
As we were finishing our tour of the indoor farm, we noticed the abundance of kale and lettuce. Sustenir explained that the reason for focusing on these ‘western’ leafy greens is to avoid competing with local organic farmers. Passionate about promoting locally-grown and accessible vegetables, Sustenir avoids growing Choy Sum, Tong Choi, or Dau Miu. Their goal is to diversify the choices for local customers while maintaining healthy relations with other organic farmers.