Imagine 12 floats riding on nutrient rich ponds. One is planted with rice saplings every week. On the 12th week the first is harvested and replanted. The cycle goes on without a break, amounting to four crops a year. No fertiliser is added and labour for ploughing and transplanting is eliminated. No irrigation either.

Fantasy? Well it has been done. Not only rice, even fruits and flowers have been grown on floats. All it requires is some subtle management of a fully integrated, zero-waste system pioneered by Dr George Chan, an environmental engineer. Chan was born in Mauritius, educated in England and served in the US. After retirement Chan spent 5 years in China from 1984. In that time he says he learnt as much from peasants there as from his university.

Chan’s starting point was the traditional, closely integrated agriculture practiced by Chinese farmers who raise crops, pigs, fish and fowl, in small spaces where the waste of one, feeds the next in a continuous chain. It is a system evolved through the centuries. And is not without disadvantages: recently it was suspected that the bird flu, escaped this knotty chain, to affect humans. Chan and Gunter Pauli, a man who champions ecology with enterpeneurial skill, have engineered some very crucial innovations into this ancient practice, and streamlined it, so that processes are scientific and continuous with no saturation occurring in any part.

Their Integrated Food and Waste Management System [IFWMS] milks bio-wastes dry and generates little atmospheric emission. Manure is rich in volatile nitrogen, which escapes into the atmosphere as nitrous oxide [N20], a notorious greenhouse gas. Instead, if manure is anaerobically digested, it yields biogas and the slurry is oxidised by bacteria into a more stable nitrite [NO2] and nitrate [NO3], which are usable by plants. Chan then leads the slurry into shallow basins to grow a green algae—chlorella— usable as protein rich fowl-feed.