ISE02/15-16

Overview of agriculture in Hong Kong

• In 2014, the daily consumption of fresh vegetables in Hong Kong was about 2 240 tonnes. Much of the food consumed is imported, with the local farms supplying about 2% of fresh vegetables. While local agriculture has a long history in supplying fresh produce for domestic consumption, its activities have been diminishing over time. This is probably caused by the transformation of Hong Kong into a predominantly service-oriented economy and the scarcity of arable land.
• In recent years, hydroponic farming has come of age and become an important method of crop production worldwide. According to the Government, there are now some 20 hydroponic farms in Hong Kong. The Agriculture, Fisheries and Conservation Department also established in 2013 a Controlled Environment Hydroponic Research and Development Centre to introduce and demonstrate the related advanced techniques and equipment to the local farmers. In 2014, the Government issued a consultation document on the new agricultural policy and proposed the adoption of modernized and sustainable agricultural practices. Yet, the views on the development of hydroponic farming collected during the consultation period appeared to be divergent with some supporting it for its high productivity and others having reservations due to its high energy dependency and investment cost^{1Legend symbol denoting For a summary of views about the consultation, please refer to Food and Health Bureau (2015).}. There are also questions about the feasibility of turning vacant factory buildings in urban areas into "plant factories" to adopt hydroponic farming practices. This issue of Essentials discusses the characteristics and challenges of hydroponic farming, and the experience of its applications in other places.

Meaning and characteristics of hydroponic farming

• Hydroponics is a technique of cultivation of growing plants using mineral nutrient solutions in water. As hydroponics does not require sunlight and soil, it provides an alternative to outdoor soil-based farming. Against this condition, hydroponics becomes applicable to vertical farming. Vertical farming generally refers to an indoor farming system which allows crops to be planted in multiple levels on a vertical axis for optimization of space use.
• Vertical hydroponic farming is a modern and knowledge based crop cultivation method. With the help of automation, it is less labour intensive. As the farm is able to be located in the city area, compared with the conventional farm in the rural area, this helps create job opportunities in the urban area and may also save transportation distance of the produce and cost for local consumption.
• Hydroponic cultivation can be applied either outdoor or indoor. For indoor hydroponic cultivation, the crops can be grown in greenhouse with the use of natural sunlight or in an enclosed space, like warehouse or multi-storey high rise factory building with an artificially controlled environment and the application of high technology. Hydroponic farming in factory buildings helps release arable land and maximize the use of land by growing crops in stackable vertical system, thus easing the issue of the scarcity of arable land in urbanized areas.
• Hydroponic farming is featured with reliable harvest, maximum crop yield and year round crop production irrespective of adverse climate conditions. The plants are grown on tiered shelves under artificial light. The temperature, humidity, light intensity, and light-versus-dark hours are controlled to optimize the growth speed and quality. It is reported that a vertical farm hectare can produce the equivalent of four to six soil-based hectares.
• Compared with soil-based farming, hydroponic farming has a high level of water efficiency. In hydroponics, the plant is nourished with nutrient laden water by drip irrigation^{2Legend symbol denoting Drip irrigation refers to an irrigation method that allows water to drip slowly to the roots of the plants. This method helps to reduce water consumption by minimizing evaporation and runoff.}. Compared with surface irrigation for soil-based farming, drip irrigation in hydroponic farming uses 80% less water.

Hydroponic farming in other places

• Vertical hydroponic farming has been regarded as one of the solutions to increase food supply for the growing population. In some places, like Australia and the United States where agriculture has always been an important economic activity, hydroponic farming is in the growing trend. At present, the development of hydroponic farming in Australia and the United States are primarily led by the private stakeholders in the farming industry. Both places exhibited growth in the hydroponic farming industry from 2010 to 2015, with an increasing revenue from the industry at an annualized growth rate of 7% in Australia, and 3.3% in the United States.
• Some places in Asia, like Singapore and Japan, try to develop vertical hydroponic farming in highly urbanized areas with a view to increasing local supply. Noting that hydroponic farming is still a novel business and requires a high level of technological input, the hydroponic farms in these Asian places are run in collaboration with research institutions and private companies in order to tap into the potential offered by biotechnology and commercial farming management.
• In Japan, hydroponic farming is highly supported by the government. In 2009, the Japanese government^{3Legend symbol denoting The Japanese government allocated the funding for the Plant Factory project in 2009 under the national strategy of revitalization. Since then, this agenda has been getting more and more recognition in particular after the heatwave attack in 2010 and 2012, and the 2011 earthquake and tsunami. All these events led to massive damage of arable land and agricultural yields, and surging food price. Against this background, the Japanese government is committed to developing climate resilient agricultural technology.} allocated 147 million yen (HK$9.2 million) to initiate an experimental project on hydroponic farming in a 1.3-hectare plant factory. Led by the Ministry of Agriculture, Forestry and Fisheries with participation from universities and private companies, the project has developed and applied research in biotechnology, artificial lighting, carbon footprint and established databases on plant growth. The major produce includes tomatoes and lettuce for local supply at supermarkets and chain restaurants. In order to enhance the commercial viability of the produce, a consumer survey was conducted in 2012 to collect views on pricing and products grown hydroponically. According to the findings, while some consumers regarded the vegetables grown in hydroponic farm more sanitary and were willing to pay around 20% to 40% more than the soil grown vegetables, there were still about 80% of the respondents found vegetables crops grown under natural sunlight more desirable.
• In Singapore, in view of its scarce land resources and heavy reliance on food imports, agriculture is seen as part of the nation's development. At present, farmland for edible crops occupies about 2% of total land area in Singapore. To tackle the issues of limited arable land and heavy reliance on imported food, a 2.4-hectare commercial hydroponic farm is set up in an Agrotechnology Park^{4Legend symbol denoting Agrotechnology Parks are modern agricultural estates developed by the Agri-Food and Veterinary Authority with the appropriate infrastructure for farming, like electricity supply and irrigation system.} with research and development support from the Agri-Food and Veterinary Authority and the Agency for Science, Technology and Research. This hydroponic farm can produce about one tonne of vegetables each day. The produce is primarily for sale at local supermarkets and supply to hospitals, hotels and restaurants. In Singapore, most farms (95%) are located inside the Agrotechnology Parks, and only a few indoor farms adopting hydroponic farming are located inside buildings.

Challenges of hydroponic farming

• One of the key challenges of hydroponic farming is its high cost, particularly to small farms. The farm takes up a higher amount of upfront investment and energy expenses in the hydroponic technology and the establishment of the controlled environment. While most hydroponic farms adopt light-emitting diode (LED) for its energy efficiency, compared with soil-based farming, its energy consumption and level of carbon footprint^{5Legend symbol denoting According to a research conducted in the United Kingdom, it was found that the carbon footprint of lettuce grown in a vertical hydroponic farm was five times greater than in conventional open fields grown in summer. In winter, the lettuce had a carbon footprint that was two times greater than open fields farming.} are still much higher than conventional farming.
• Another challenge is the types of crop suitable for hydroponics. At present, hydroponic farming is used to grow primarily leafy vegetables and herbs, like lettuce, Chinese kale, Chinese cabbage, spinach, broccoli, flowering Chinese cabbage (菜心), water spinach (通菜) and fruits like strawberries. While hydroponic farming works well with leafy vegetables, large and heavy crops like wheat, maize, root vegetables which require high intensity of light or soil anchorage are found not viable for stackable growth.
• Compared with conventional soil-based farming, vertical hydroponic farming offers a solution for the shortage of arable land in urban and city areas and provides an alternative resilience for food security and climate change impacts. However, being at the novel state, its application in an extensive scope would depend on the further improvements of reducing energy consumption, establishing a competitive price of the produce and promoting the hydroponically grown vegetables to the local consumers.

Observations

• The development of hydroponic farming involves various issues relating to food supply, agricultural policy, biotechnology and farmland resources. In Japan and Singapore, while the farms are commercially run by the private operators, government policies and support are in place to facilitate their development.
• In Singapore, although hydroponic farming is technology-based, it is still classified as an agricultural activity according to the land zoning policy. Hence, for the establishment of an indoor farm inside a business building, approval is required from the Urban Redevelopment Authority. It is observed that in most cases, the Singapore government has allocated farmlands inside the Agrotechnology Parks for agricultural activities. In Japan, agricultural land occupies about 12% of the total land use^{6Legend symbol denoting Total land area in Japan is 38 million hectares comprising about 67% (25 million hectares) of forest, 12% (4.6 million hectares) of agricultural land and 5% (1.9 million hectares) of urban land.} and the availability of farmland is generally not a pressing issue. Most hydroponic farms are situated in the open space while only a few are established inside factory buildings which have been converted for use after abandonment.
• Either in Japan or Singapore, the government leads the relevant departments or research institutions to provide the required technological expertise to the hydroponic farms. The focus of the research is to advance the hydroponic application in farming and reduce energy consumption.
• Apart from research development, the governments in Japan and Singapore also help to promote hydroponically grown produce. In Japan, the Ministry of Agriculture, Forestry and Fisheries and the Ministry of Economy, Trade and Industry, with an objective to revitalize the agricultural industry, jointly promote hydroponic farming and its produce both to the industrial stakeholders and consumers through trade fairs. In Singapore, the government has established a fund for local farmers to adopt measures enhancing crop productivity and efficient use of land, like vertical hydroponic farming.
• Hydroponic cultivation is found to be a feasible farming method with a special advantage to the scarcity of arable land in urbanized areas. However, there are concerns of its financial viability associated with high upfront investment, high energy consumption and extensive technology application. For places where the agricultural industry is not a major economic activity or where hydroponic farming is still not widely adopted, like Singapore and Japan, their experiences have shown that government support has been provided at its early stage of development.

Prepared by Angela CHOI
Research Office
Information Services Division
Legislative Council Secretariat
14 October 2015