China's soil deterioration may become growing food crisis, adviser claims

Jonathan Watts in the Guardian (UK): The quality of China's overworked, polluted and artificially fertilised soil needs to be protected or the country could struggle to grow enough crops for the 300 million to 400 million people who will move from the countryside to the city over the next 30 years, a senior government adviser warned today.

Han Jun, an expert on rural policy at the Development Research Centre, said maintaining food security was a major challenge in the process of urbanisation as farmers moved off their fields and into cities, where the consumption of meat, grain and diary products was higher. In the next three decades, he predicted the share of urban residents in China's population would rise from 47% to 75%, which would require the clearance of land for residences, roads and other infrastructure.

Noting that China feeds 22% of the world population with only 10% of the planet's arable land, he said the pressure was growing. "The deterioration in soil quality is now a very important problem," Han told reporters in Beijing. "I believe improving the quality [of soil] is of equal importance to protecting the amount of arable land."

The main causes of the decline are inappropriate farming techniques and industrial pollution. Han, who has helped to draw up the cabinet's rural policies over more than seven years, said more than twice as much nitrogen fertiliser is used on the average hectare of Chinese farmland as the global average.

Factory waste, including heavy metals and other toxins, has contaminated more than a tenth of the country's farmland, he said. The government said earlier this monthn that it would draw up countermeasures, when the country's first pollution census revealed farm fertiliser was a bigger source of water contamination than factory effluent.

The risks of inaction are well known. Han, who comes from a rural background, said farmers do not use pesticide, fertiliser and other chemicals on crops they grow for their personal consumption. But he warned that it was unrealistic to expect a population of 1.3 billion people to maintain food self-sufficiency without artificial boosts for production….

A lotus field in southern Hubei province, near Wuhan. Shot by Politizer, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license