Soilless Science in Shanghai

Modern hydroponic techniques were used in China as early as the 1970s to grow rice and vegetable seedlings. During this period, researchers at Shandong Agricultural University (SAU) developed the ‘Lu-SC’ hydroponics system, which was used to grow greenhouse vegetables in the Xinjiang and Shengling oilfields. In the 20ha devoted to this system, yields were reported to be 135% that of vegetables grown in the open field.

In the 1980s, Beijing Agricultural University, Nanjing Agricultural University, Chinese Academy of Agricultural Sciences (CAAS), and several Academies of Agricultural Sciences also began research on hydroponics. Currently, the total hydroponic production area is more than 100ha, mainly concentrated around large cities such as Shanghai, Beijing, Nanjing, Hangzhou, and Guangzhou and oil production areas such as Xinjiang, Daqing, and Shengli.

Hydroponics systems used in China include both technically sophisticated systems, such as NFT and DFT, and systems developed in China to meet local needs. The ‘Lu-SC’ system, the Floating Capillary Hydroponics (FCH) developed by Zhejiang Academy of Agricultural Sciences, and the Solid Manure Soilless Culture System (SMSCS) developed by CAAS, are simple, cheap, and easy-to-operate. The characteristics of these Chinese-developed systems make them competitive with outdoor crops in the large-scale production of fruit and leafy vegetables. Flowers and medicinal plants are cultured on a smaller scale.

Specialised institutes and units have been established for hydroponics: the Hydroponics Research Center of Southeast Coast, established in 1986; and the Special Organization for Hydroponics in the Academic Society of Chinese Agricultural Engineering, established in 1985.

Although a relatively recent introduction to Chinese agriculture, hydroponic cultivation has developed rapidly in the past several years, and holds considerable potential for the future.

Shanghai vegetable industry

With a population of more than 23 million, Shanghai is one of the largest metropolitan areas in the world. Located in the delta of the Yangtze River, it is the largest industrial and commercial city of China, its total area covering 6,340.5 km2, of which 13% is urban area and 87% rural.

In the past 10 years, Shanghai has been expanding rapidly, in 1994-95, for example, the built-up area increased by 22.4 km2. The average population density is about 2,059 people/km2, the highest density being in Nanshi District with 58,233 people/km2. In order to reduce the population pressure in the town centre, the administration implements a policy of moving people to the fringes of the town, together with industries and facilities.

To keep pace with the growing demand for food, the Shanghai vegetable production industry, including greenhouse crop production, has expanded considerably in the last 40 years. Prior to 1964, vegetables were grown in the open field, but since that time, vegetables have been produced under small plastic tunnels, large plastic tunnels and then expanded to multi-span glasshouse culture. Dutch-style heated glass greenhouse designs have been successfully used in vegetable culture in Shanghai, providing yields of tomato and cucumber that are up to four to six times greater than tunnel culture. In the 1990s, vegetables grown out of Shanghai began to enter the city, and gradually held most of the local market, which brought about great impact on Shanghai vegetable production. As local vegetable production gradually loses local market share caused by the impact of huge supply all over the nation, Shanghai’s vegetable industry is facing challenges to improve its competitive ability by targeting the segment market and developing products characterised by freshness and quality.

Shanghai also faces challenges ahead that include adjusting crop proportion, promoting protected cultivation, expanding resource saving and environmentally friendly cultivation areas, and enhancing its cooperation with the national vegetable production base.

The establishment of agriculture parks, promoting the integration of urban and rural areas, has been one of the initiatives to address these issues and to support the sustainable development of Shanghai’s vegetable industry into the future. These urban agricultural zones also attract considerable foreign investment, advanced technologies and agricultural professionals.

Shanghai’s numerous modern agricultural zones include Sunqiao Modern Agriculture Development Zone in Pudong New Area, Fengxian Modern Agriculture Zone in the south Fengxian District, and many others in the suburbs including the districts of Baoshan, Jiading, Minhang, Songjiang, Jinshan as well as Chongming County.

Sunqiao Modern Agriculture Development Zone

Located in Shanghai’s Pudong New District, south of the Chuan Yang River, the Sunqiao Modern Agriculture Development Zone was constructed in September 1994. The development zone is led directly by the Countryside Development Bureau of Pudong New Area and managed specifically by Shanghai Sunqiao Modern Agriculture United Development Co., Ltd. The company pursues the “industrialised management of agriculture.”

Pudong New District arose from China’s policy of ’Opening Up’ economic development – the area is now considered the epitome of an export-oriented, modern new urban district, and is synonymous with both China’s economic reforms and prosperity and Shanghai’s modernisation and prestige as a centre of world commerce.

China’s first modern agricultural development zone as well as a state-level education base for the popularisation of science, Sunqiao Modern Agriculture Development Zone is the fifth functional development zone in Pudong, following the establishment of Waigaopiao Free Trade Zone, Lujianzui Finance and Trade Zone, Jinqiao Export Processing Zone and Zhangjiang Hi-tech Park. Since its founding, the Zone has been approved by the state as one of 21 national agricultural science and technology zones.

In May this year, as part of the 2012 International Conference & Exhibition on Soilless Culture (see story on page 30), Dr Li Qiansheng, Secretary of the Shanghai Institute of Technology, led a field trip to Sunqiao Modern Agricultural Development Zone to view first-hand its world-class facilities. Production demonstrations, tourism and sightseeing, science education and information on opportunities for foreign export are also on offer.

The goal behind establishing this development zone is to speed the building of advanced modern agriculture and to integrate urban and rural areas in Pudong. It aims to be a demonstration base to promote the development of modern agriculture on the outskirts of Shanghai and in the valley of the Yangtze River.

The Shanghai Sunqiao Modern Agriculture Development Zone includes workshops for edible fungus manufacturing, seed processing, vegetable processing, and vegetable seedling breeding; a glass greenhouse; and a tissue culture room.

Sunqiao’s Biotechnology R&D Centre was established in June 2010. It uses modern biotechnology to solve some of the problems associated with breeding new crop varieties and species degradation as well as to produce healthy, virus-free seedlings with plant tissue culture techniques for detoxification and rapid propagation.

Using sophisticated technology, the facility offers commercial production of virus-free plantlets, including strawberry, lily, potato and other crops. The centre also provides high quality plantlets such as Phalaenopsis, Cymbidium, Dendrobium and other flowers.

The facility also provides organically grown fruit and vegetables, flowers, mushrooms, fungus, honey and other products to the city’s high-end hotels, restaurants and supermarkets. Some produce is sold in Hong Kong.

Greenhouse development

One of the key projects in Shanghai Modern Agriculture Development Zone is the Huandong Agriculture Demonstration Area. Consisting of 3ha of greenhouses imported from the Netherlands, with a total investment of RMB 27 million yuan, the area uses the most advanced Priva control system to regulate temperature, humidity, radiation, CO2 and other environmental factors.

The facility also features 105,000 square metres of plastic tunnels. Here, the focus is on new technologies that increase quality, productivity per square metre, and eliminate soil pollution and disease.

Greenhouse production uses biological integrated pest management and vegetables are nourished on pure rainwater, specially compounded nutrients and carbon dioxide.

Soilless culture, drip irrigation with liquid fertiliser, irrigation with collected rain, artificial supply of CO2, and supplementary pollination by bees are all adopted practices in the greenhouse. Unit yields are seven to eight times more than those of normal plastic tunnels while vegetables grown are of premium quality, rich in vitamins, minerals and amino acids, and are excellent for table use and cooking.

Also within the Shanghai Modern Agriculture Development Zone is Luling Horticulture Company, a subsidiary of Shanghai Sunqiao Modern Agriculture United Development Co., Ltd. The company has nine multi-span greenhouses and 500 plastic tunnels built in an area of 23ha.

Advanced facilities and technologies include spray, drip and micro-sprinkling, nutrient solution culture.

A variety of vegetables

More than 20 types of organic vegetables grow in water in ceiling containers, on the walls and around pillars. Hydroponically grown vegetables include cucumbers, tomatoes, eggplants and green peppers.

Hydroponically cultivated sweet pepper varieties include green, red, yellow, orange, white and purple. Peppers can grow to a height of 4m and take only 40 days from florescence to harvest. Annual yield of sweet pepper can reach 15 kg/m2.

Cherry tomatoes grow to a diameter of around 1-3cm, with rapid plant growth in the varieties of seedlings planted 70 days after the fruit is mature. Harvest is around 7 months. Annual yield can reach 20kg/m2.

Aside from cherry tomatoes, a variety of other tomatoes hydroponically cultivated include beef tomato and truss tomato. The weight of each ripe fruit ranges from 150g to 500g. One tomato plant in the greenhouse can grow to a length of 12m while annual yield can reach 25 to 35kg/m2.

Cucumber plants in the greenhouses can grow to a height of 14m over a period of 4 months, needing only 40 days from planting to harvest. Annual yield can reach 35kg/m2.

In the growing zone

The rivers Yingjia,Yuejin and Laodong in the Sunqiao Modern Agriculture Development Zone all lead to the Chuanyang River, providing convenient irrigation for the area. The Zone has ISO14000 environmental quality system accreditation. The area boasts flat topography and fertile soil with convenient irrigation and draining systems. Groundwater level is 1-1.2 metres, with the pH value of water ranging from 7.5 to 7.8, and EC value from 0.6 to 0.9. The pH value of soil is about 7.5.

The Zone enjoys a mild and moist climate with marked seasonal changes dominated by East Asia monsoons in the north sub-tropical zone, an annual average sunshine time of 2,091 hours, and an annual total sun radiation of 477.5 kilojoules per square centimetre. The annual average temperature in the Zone is 15.50C, with the extreme highest being 380C and the extreme lowest –9.60C. In addition, it enjoys 230 or so frost-free days and about 131 rainy days in a year with an annual rainfall of 1087mm.

The comprehensive pollution indices of the irrigation water, soil, and air in the Zone are all up to required standards – ideal for the production of quality green food for the rapidly expanding population of Shanghai.

About the author

Christine Paul is a Sydney-based journalist and regular contributor to PH&G with a special interest in the environment and sustainable technology.

PH&G September/October 2012 – Issue 126