David Montgomery in Dirt, The Erosion of Civilizations, argues that the twin problems of soil degradation and accelerated erosion (with an estimated twenty-four billion tons of soil lost annually around the world) eventually determine the fate of civilizations. The pressure of growing world population intensifies these problems, with Montgomery noting that “to feed one human requires .2 hectares (approximately 1/2 acre) per person.” With a land mass of 426 square miles and a population of 7,000,000, Hong Kong is one of the most densely populated areas in the world, with approximately 17,000 people per square mile.
With the growing concern in Hong Kong over the food supply in China, reporter Mary Hui in the New York Times recently reported in her article, “In Organic-Hungry Hong Kong, Corn as High as an Elevator’s Climb,” that Hong Kong consumers “are striking out on their own by tending tiny plots on rooftops, on balconies and in far flung, untouched corners of highly urbanized Hong Kong.” She quotes one rooftop gardener voicing his concern about “the food scandals in China: the formaldehyde that is sometimes sprayed on Chinese cabbages, the melamine in the milk and the imitation soy sauce made form hair clippings” as reasons for growing his own food. The Times article reports a remarkable increase in organic farms in Hong Kong: “There are about 100 certified organic farms in Hong Kong. Seven years ago, there were none.”
What is the source of the organic soil for these farms? Reporter Hui interviewed Osbert Lam, the owner of a rooftop operation in Hong Kong called City Farm, who revealed the difficulty of growing food in Hong Kong’s humid, subtropical climate. Starting with imported organic soil from Germany and Denmark, Mr. Lam for a year “had to tinker, sift, mix and adjust before arriving at a suitable recipe” for his soil, with more sand to grow potatoes, more peat moss for strawberries, etc.
According to David Montgomery in Dirt, his must-read history of world agriculture, there are three great regions on our planet Earth “where thick blankets of easily farmed silt can sustain intensive farming even once the original soil disappears.” The wide expanses of the world’s loess belts in the American (U.S. and Canada) plains, Europe, and northern China are the Earth’s breadbaskets. Most of the rest of the planet has “thin soils over rock” which must be carefully nurtured by the practice of intensive organic agriculture which rebuilds the thin soils.” Mr. Lam’s struggling to grow food in his rooftop Hong Kong operation is a reminder how we Americans are truly blessed to be living in one of the world’s loess belts.
(FW Barrie, 10/6/12)