A local organic-agriculture consultant is surprised by results that Hong Kong's farmed foods are largely free of pesticides and heavy metals. 'If that's the case and it is verified by a lab, I'm delighted,' said Bruce Derrick, who has advised clients in Asia for 35 years on fertiliser production, mushroom cultivation and open agriculture projects. Mr Derrick would have predicted that locally grown foods would show some form of contamination - considering Hong Kong once relied heavily on chemical fertilisers, as well as dangerous pesticides, herbicides and fungicides. While he believed evidence of tainted soil would 'inevitably crop up' in further tests, the 71-year-old expert did agree with the latest findings that organically grown foods contained more nutrients and were more expensive. 'If you ever tasted something that is 100 per cent organic, whatever it is - whether it's meat from an animal that's fed organically or whether it's a vegetable or a fruit - the taste is incredibly different from something that's been raised in chemicals,' Mr Derrick said. Organic food, however, should not cost more, he noted. Globally, organic-food farmers do not use expensive pesticides and fertilisers. They are making their own, he said. 'If it's organic, it should cost the same or preferably less,' said Mr Derrick, adding that organic foods have fallen victim to 'commercial exploitation'. Mr Derrick maintained that most of Hong Kong's organic-food farmers use methods that are not completely organic. Either the soil is not rehabilitated, fertilisers are not all natural or the employees are not professionally trained, he said. 'The organic people here are great, well-meaning nice people and doing their best, but they're not professional,' he said. 'They haven't studied the thing, and are [not] doing it the way it should be.' Mr Derrick, cited as an Outstanding Earth Champion by the Earth Champions Foundation last year, also has some interesting ideas for addressing the world's food shortages. He has blueprinted a model, a self-sufficient farm that can feed 5,000 to 10,000 people a day. 'This can be done anywhere in the world,' said Mr Derrick. 'I envisaged something like this 30-odd years ago, but the technology in certain aspects was not available. Now it is.' Mr Derrick's dream farm would cover 50 hectares. It would run 24 hours a day with 300 workers on 12-hour shifts. A thousand cattle and 1,500 pigs would eat organic materials before being slaughtered at a farm-based abattoir, located near research and development workshops and laboratories. Five thousand free-range chickens would roam. Twelve thousand eggs would be handled per week. A mushroom farm would produce five tonnes of fungi a day. The US$250 million project, 'recoverable over five years', could be built on an island, inside a city centre, even on a retired aircraft carrier or a tanker, Mr Derrick said. 'We need to produce food and it can be produced on a continuous, high-quality basis.' On his farm, waste would flow into a biogas digester, a contraption that would produce methane for generators and provide carbon dioxide for 50-metre-high greenhouses. Solar panels would generate electricity and heat water. A 4.5-million-litre freshwater reservoir would be filtered and purified. Nearby trout and yabbies would swim. Asked why this project was so important to him, Mr Derrick replied: 'Why do you buy your wife a diamond necklace?' His answer, with a smile: 'Because it needs to be done.'