Huang Chunhua is concerned that his fellow farmers in Panyu district, just outside of Guangzhou in South China's Guangdong Province, don't understand that as times have changed so has the waste they have been using to fertilize their crops.

"They're only familiar with the garbage fertilizers that mainly contain kitchen remains, and those have been effective in the past. They don't realize that development has caused more industrial waste to seep into the garbage," Huang told the Global Times.

Of particular concern are the increasing amounts of toxic materials such as batteries, especially given the fact that vegetables fertilized with this material were being sold at nearby markets, according to a Weibo post made by local environmentalist Jiang Xicheng in December.

The authorities have also taken notice. According to a December report, the Guangzhou agriculture bureau tested soil samples taken from the area and found excessive levels of cadmium, a heavy metal pollutant hazardous to human health. One sample contained cadmium at a level of 0.959 milligrams per kilogram. China's legal limit of cadmium in soil is 0.3 to 0.5 milligrams per kilogram.

Air pollution has been an issue of public concern recently, given the intense smog that has blanketed the north of the country in recent weeks. Water pollution has also been a widely canvassed issue in the press, given the high profile nature of projects such as the North-South water diversion project. Soil pollution however, as is the case with soil itself, often stays below people's sight-line.

"It's harder for people to notice soil pollution," Guo Hongyan, an environmental professor with Nanjing University, said. "But the threats of soil pollution are serious. Polluted soil will contaminate food, water and air."

A widespread problem

China has at least 10 million hectares of polluted arable land, 2.17 million hectares of arable land irrigated by polluted water and 133,333 hectares of land that has been destroyed or occupied by excessive solid waste, according to statistics published by the Ministry of Environmental Protection in 2006. This effectively means that contaminated land makes up 10 percent of the country's official minimum of 120 million hectares of required arable land, a "red line" the country drew to ensure grain security for the world's largest population.

Between 2006 and 2010, the government carried out a nationwide investigation into the environmental state of the nation's land, but the results were not published. A statement was released instead saying that the collected data had not been classified due to the large volume.

According to a report from the World Bank on China's soil pollution in 2010, China began to significantly pollute its soil in the 1950s following the industrialization of the country, and the pollutants have mainly come from refineries as well as mining and chemical plants. There are also significant quantities of organic pollutants and waste from electronic equipment.

Guo said that the public has only recently begun to pay attention to soil pollution due to high profile cases such as the pollution in Panyu district. But the Panyu case is far from isolated.

In 2004, three workers showed symptoms of being poisoned at the construction site of Songjiazhuang subway station in Beijing, which were caused by chemicals left behind by a demolished pesticide factory that had been established in the 1970s, according to the World Bank report.

In Wuhan, Hubei Province in 2007, several workers were poisoned at a construction site in Hanyang district, which was the former location of a pesticide factory. The city government gave the developer 120 million yuan ($19.25 million) in compensation, and had to spend more than 280 million yuan restoring the soil condition of the land before 2014, said the report.

In 2009, local farmers found their livestock had died after eating grass in Zhangjiaying village in Qujing, Yunnan Province. The local government discovered that thousands of tons of chromium residue had been dumped near the village, according to a previous Global Times report.

In Togtoh county in the Inner Mongolia Autonomous Region, the polluted water created by a branch of the Shijiazhuang-based CSPC Pharmaceutical Group Limited, which has a factory in the county, has left most of the arable land there unable to be used for planting grain.

Rising awareness

"China faces a tough task in solving soil pollution. People first began to understand the effects of soil pollution in the 1970s, but the public's indifference in the past has made the situation worse," Ma Tianjie, an environmentalist from Greenpeace, told the Global Times.

Zhu Lijia, a professor with the Chinese Academy of Governance, told the Global Times that poor supervision is contributing to the problem. "If the government was strictly supervising them, these things wouldn't have happened," Zhu said.

Pan Genxing, a soil expert with Nanjing Agricultural University agreed. "The economic incentives and a lack of supervision are worsening soil pollution," he said. "The public are indifferent when it comes to the pollution of public resources," he added, also pointing out that the country's growth trajectory means that soil pollution may continue for another three decades.

Last week, the State Council issued a notice in an effort to combat the problem. The notice said that by 2015, the country should comprehensively assess the soil situation across the country, and by 2020, the country should establish a sound soil protection system. This came after a State Council meeting held on October 31, when the cabinet was alarmed that human activities had caused vast pollution to the country's soil.

The country and enterprises should set up supervision systems, Pan suggested. "Enterprises must be placed under the supervision of local authorities."

A special law on soil protection would provide a legal basis when the public fights against pollution, Guo said. "We follow the principle that 'people who cause pollution should be responsible for remediation,'" he said, but pointed out that in many cases, it is difficult to identify the polluters responsible, in the same way it's hard to say who is responsible when a company goes bankrupt.

A system of collective responsibility could be applicable, which means companies within certain industries could pay up front for future pollution they might cause, Ma Tianjie suggested.