CHINA鈥橲 economic revolution is coming at a cost. While improved prosperity and government incentives convinced millions of people to give up the rural life and move into towns and cities, China鈥檚 agriculture is in rapid decline, prompting fears that the country that is home to one-fifth of the world鈥檚 population will soon be unable to feed itself.
Those fears have been heightened by two new reports by Chinese scientists. They reveal that a national push to encourage farmers to abandon the millennia-old tradition of growing rice in favour of fruit and vegetables is having a profound and detrimental affect on the quality of China鈥檚 soil and water. After just five years, fields growing fruit and vegetables are becoming more acidic and barren, while nitrogen and phosphorus levels and fungal epidemics are rising sharply.
Since 1998, the area of land in China devoted to grain crops has fallen by 15 per cent. Last month, Beijing confirmed that grain yields have fallen by a fifth in that time, and consumption this year is expected to exceed production by a record 37 million tonnes. This demand for imported grain has triggered a 30 per cent rise in global grain prices this year, and further rises are expected as Chinese demand soars.
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The root problem is that China is urbanising fast. Already 500 million Chinese live in towns and cities, and the government wants that to rise to 800 million by 2020. Cities are spreading across former farmland and are getting first call on scarce water resources. They are also changing food markets: while prices for grains such as wheat and rice are capped by the government, city people are willing to pay high prices for fruit and vegetables. And the government is encouraging millions of farmers to meet this soaring demand by converting rice and wheat fields to growing these more profitable crops (see 鈥淔ruits of prosperity鈥�).
As a result, in the past decade, farmers have converted 13 million hectares, an area the size of England, to fruit and vegetables. It is this unprecedented change that has triggered the new concern about deteriorating soils.
Researchers from the government鈥檚 Institute of Soil Science in Nanjing have found that soils in fields converted to growing vegetables are becoming dramatically more acid, with average pH falling from 6.3 to 5.4 in 10 years. Meanwhile nitrates in the soils are at four times previous levels, and phosphate levels are up tenfold (Environmental Geochemistry and 午夜福利1000集合, vol 26, p 97 and p 119). The changes in soil chemistry have been accompanied by an equally dramatic decline in soil bacteria and an epidemic of fungus. The deterioration is worst when the crops are grown under plastic.
These changes are starting to hit vegetable yields and quality. 鈥淪ome plants show abnormal growth, deformed fruits and various plant diseases which are not easy to control by the usual pesticides,鈥� says Cao Zhihong of the Institute of Soil Science. There is, in addition, 鈥渨ide concern because of possible groundwater and well drinking water pollution by leached nitrates and phosphates鈥�. Already, a third of well water exceeds government norms for nitrate.
鈥淎nything that disrupts microbial activity and function in soil could be expected to affect long-term soil productivity, and have serious consequences,鈥� says Rui Yin, a co-author of the studies.
Western agronomists suggest that changes in soil chemistry are not being caused by growing fruit and vegetables, but by farmers applying too much fertiliser to them. While China harvests a similar amount of the crops to the US, it uses almost twice as much fertiliser, says Lester Brown, president of the Earth Policy Institute in the US and an expert on Chinese agriculture.
Fruits of prosperity
Wang Shiping is typical of China鈥檚 new breed of farmer. He lives in the village of Ermaoqu in northern Shaanxi province, which has recently started growing green beans, peanuts and water melons on former grain fields. Farmers have turned over many of the old hillside terraces to apple orchards.
Twice a week, Wang goes to the nearby town of Qinghuabian to sell his water melons. 鈥淟ife has changed here since we started growing water melons,鈥� he says. 鈥淢y income has increased four times. Now we can all afford televisions and motorcycles. Five years ago we had only ragged clothes, but now we buy good clothes in the town market.鈥�
The prosperity comes despite the Chinese government recently taking many of the steeper hill slopes, including more than a third of Wang鈥檚 3-hectare farm, to plant trees in an effort to stabilise crumbling hillsides.
Wang and his fellow farmers are stretching the natural resources to the limit. They now use almost every drop of water that falls on the land to irrigate their crops. 鈥淪ince the vegetable project started there is almost no river in the valley,鈥� he says.
But there is a bigger potential problem than water shortages. The country鈥檚 one-child policy, coupled with young people migrating to the cities, is leaving behind an ageing and often shrinking rural population. The youngest child in Ermaoqu is 7 years old, says Wang whose 21-year-old daughter has left to go to college. 鈥淪he鈥檒l stay in the city,鈥� he says. 鈥淐ity work is harder than farming. Here we have half a year with nothing to do except play cards. But even so, if I was 20, I鈥檇 go to the city.鈥�
In the past the villagers produced their own food. Now they buy much of it. Wang has not yet seen any deterioration in the quality of his soil or crops. But if the government researchers are right, that may happen soon. And as more villages take Wang鈥檚 route to prosperity, a question first posed by Lester Brown of the Earth Policy Institute becomes ever more urgent: who will feed China?