Soil and the City

I have spent most of my living and working life in the countryside, surrounded by open fields, woodlands and hills, and in close contact with the soil. I recently changed my job and moved to the University of Manchester, which is in the centre of one of the largest cities in England. Because of this move my contact with soil is much less; in fact, as I walk each morning to my office, there is hardly a handful of soil to be seen. But is this really true of the whole city? Concrete, asphalt, and bricks certainly seal much of the ground in Manchester, as in most cities and towns. But soil is in abundance: it lies beneath the many small gardens, flower beds, road and railway verges, parks, sports grounds, school playing fields, and allotments of the city. In fact, it has been estimated that almost a quarter of the land in English cities is covered by gardens, and in the United States, lawns cover three times as much area as does corn. As I write, I am on a train leaving central London from Waterloo Station, and despite the overwhelming dominance of concrete and bricks, I can see scattered around many small gardens, trees, flowerpots and window boxes, overgrown verges on the railway line, small parks and playing fields for children, football pitches, grassy plots and flower beds alongside roadways and pavements, and small green spaces with growing shrubs outside office blocks and apartments. The city is surprisingly green and beneath this green is soil. Throughout the world, more and more people are moving to cities: in 1800 only 2 per cent of the world’s population was urbanized, whereas now more than half of the global human population live in towns and cities, and this number grows by about 180,000 people every day. This expansion has been especially rapid in recent years.