Grace Chua Straits Times 15 Jul 10;
FACTORIES, long a fixture on Singapore's landscape, churn out electronic goods, pharmaceuticals - and now, leafy green vegetables too.
The national food authority has developed 'vegetable factories' - stacked racks of lettuce, kai lan, xiao bai cai and Chinese cabbage - that can save space and cut pesticide use.
The Agri-Food and Veterinary Authority (AVA) is showing off its high-rise farm system at the Singapore Garden Festival from today to next Thursday at the Suntec convention centre.
The system, developed in the last two years, is aimed at companies which may have spare warehouse or factory space, or restaurants which want to grow vegetables in their backyards, explained Mrs Lam-Chan Lee Tiang, AVA's head of horticulture technology.
It consists of vegetables planted in soil-filled trays that are stacked on a bookshelf-like rack up to 10 shelves high.
An enclosure keeps pests out so farmers need not use chemical pest-killers, and the temperature can be controlled to allow for different plants to be grown.
Fluorescent or LED lighting does away with the need for natural light, which has traditionally posed a challenge for such high-rise farm systems, said Mrs Lam-Chan.
While hydroponics and aeroponics are able to use similar space-saving rack systems, customers here prefer soil-grown vegetables, she added.
That is because soil-grown greens are firmer when cooked, as many Asian vegetable dishes require.
The cost of such a system is somewhere between conventional agriculture and hydroponics or aeroponics.
Each four-layer stainless steel rack, with lights and materials, costs about $2,200 and can produce about 288kg of vegetables a year.
A four-layer rack uses 28-watt fluorescent tubes, but the AVA is still experimenting to find the best light conditions for growing.
Japan already has about 50 'veggie factory' systems, said Mr Satoru Matsuno, manager of Fairy Angel, which has three such factories in Japan.
Each factory costs about 3 million yen (S$46,800) per square metre, a figure that includes the land, the building, the rack system and energy supplied by solar panels, he added.
But organic farmer Ivy Singh-Lim, who runs Bollywood Veggies in Kranji, questioned the environmental friendliness of the racks' energy consumption and use of plastic.
'It's a typical prim-and-proper, plastic-and-progress display,' she scoffed.
Singapore's farms produce 7 per cent of the 136,382 tonnes of leafy vegetables consumed here each year, and the AVA aims to raise that figure to 10 per cent in the next few years.
A hectare of conventionally farmed land produces about 90 tonnes of vegetables a year, but stacked factories could multiply that, the AVA's Mrs Lam-Chan said.
Other urban farming solutions include aeroponics - growing vegetables in air and spraying their roots with a nutrient mist - as well as rooftop and vertical growing.
