文章 Articles

"A sea of plastic"

Short-term profit motives have led China’s farmers to use polluting plastics, chemical fertilisers and herbicides in abandon. The country needs sustainable farming to preserve the quality of its food – and its land, writes Jiang Gaoming.

Article image

During my recent visits to villages in the Chinese provinces of Henan, Hebei, Tianjin and Shandong, I saw the phenomenon of “white pollution” with my own eyes. This “white terror” is the sea of plastic that covers our land and blows on the breeze along the highways.

This plastic membrane used in agriculture can be seen strewn between fields, in ditches and beside roads – you even see it on streets in towns and in household courtyards, piled layer upon layer. I have visited dozens of countries, but never seen plastic used on such a scale as it now is in China. And it looks as if the country’s five millennia of agricultural history may now be destroyed by the excessive use of plastic membrane, fertiliser, pesticides and herbicides. 

Plastic has two main uses in farming – to construct plastic greenhouses for growing crops out of season, and covering the ground to increase the value of crops. In the provinces of Shandong and Hebei, I saw it used to grow almost every crop, apart from cereals like wheat and maize. Peanuts, potatoes, watermelons, garlic, eggplants, peppers and tobacco are all grown under plastic.

The farmers say that covering the ground with a plastic membrane increases the temperature and humidity of the soil, extending the growing season and increasing harvests by 20% to 50%. When growing crops such as peanuts, they say, it can even double production. This method of farming may be a new scientific advance, but nobody has considered whether our environment can cope with the plastic waste that results. Currently, about half a million tonnes of the plastic is left in the soil every year, almost 40% of the total plastic used. This forms a layer in the earth which is less permeable to water and air, making it harder to farm.

More careful farmers will remove the membrane from their fields at the end of the growing season, but they only go so far as to throw it to the edge of their land. The plastic is light and covered with earth, so it is difficult to sell for recycling. When there is a big enough pile of the stuff, the farmers generally burn it – polluting the environment even further.

Plastic can be seen across China's fields

Organic compounds which do not biodegrade are known as Persistent Organic Pollutants (POPs), and 12 of the most harmful of these chemicals were restricted or banned by the 2004 Stockholm Convention on POPs. These compounds linger in the environment for long periods and can enter the human body through food or respiration, causing poisoning, cancers and even death. Burning plastic membrane results in the release of at least five of the 12 POPs listed by the Stockholm Convention.

Ten years ago, officials from the Ministry of Agriculture and Ministry of Science and Technology expressed hopes that scientists could develop a microorganism to break down plastic waste – but there has been little success. Despite frequent and promising-sounding reports to the contrary, these methods are expensive and ineffective, and the farmers simply do not use them. Officials and their scientists have both made a fundamental error: plastic is not something that can be dealt with by the natural world. The solution is to look for an alternative material or use policy measures to stop its use, and control the pollution at the source.

While it may be true that the large-scale use of plastic membrane increases production, it also lowers quality. All living organisms will suffer and lose quality if you force them to grow in an unnatural manner, such as cultivating them very rapidly. It can mean a loss of flavour, as well as pollution in the fields. Thanks to the use of plastic membrane and fertiliser in agriculture, I have seen garlic shoots thicker than my thumb – impossible 20 or 30 years ago – but the farmers themselves will tell you that the flavour is not the same. In the past, garlic would be covered with straw and natural fertiliser, but now plastic membrane and chemical fertilisers are used, and the taste has suffered.

Some will say that since the harvests are bigger, the farmers can earn more. But in reality, the extra income is divided up among other parties, with little left for the farmers themselves – even though they bear the risks. In practice, the merchants who sell the plastic, exporters, wholesalers, local traders and retailers all want to divide the extra income. Extra earnings that come from waiving agricultural taxes or from increased subsidies are quickly swallowed up by increases in the cost of raw materials – and the farmers are left to deal with the pollution. They remain at society's lowest level, and never earn as much from greater harvests as they can by leaving the land and working in the cities. In one area, I saw the price of garlic shoots drop from 1 yuan (US$0.15) a kilogram to 0.6 yuan over the course of two days. Last year, freshly-picked garlic sold for 2.4 yuan a kilogram; this year it only fetches 1.4 a kilogram. With every household planting the same crops, the farmers are unable to withstand the market risk.

Covering the ground with plastic and chemical fertiliser is comparable to feeding it with opium: crops grow bigger and faster, but the land becomes unhealthy and reliant on artificial support. Nowadays, farmers often say that nothing will grow without lots of fertiliser. The plastic, fertiliser, pesticide, herbicide and additives accumulate in the soil and sap its vitality in the long term.

Farmers rely on the land for their living, and it is vital that we protect the land, rather than encouraging farmers to use unnatural methods for the sake of short-term profit. Yet the widespread use of plastic membrane has been promoted by the Ministry of Agriculture and government.

Instead of turning the earth white with plastic, we should be using organic material to make it darker: feeding straw to livestock to produce meat, milk and dung. This dung can subsequently be used to produce methane, and the residue can fertilise the fields. Increasing the organic content of the soil and improving its structure will allow high levels of sustainable – rather than short-term – production. Livestock and energy production will be increased, and the value added to the land will be much greater than using plastic. The use of organic fertiliser will reduce the volume of chemical fertilisers used, and eliminating the use of plastic will reduce costs and put a stop to this “white pollution”. These are all needed to provide a healthy path forward for China’s agriculture, and must be considered by the Ministry of Agriculture, the State Environmental Protection Administration (SEPA), Ministry of Land and Resources and the Ministry of Science and Technology.

Farmers’ income must be increased through appropriate measures, with increased production and increased efficiency going hand in hand, the land being protected and pollution reduced. Short-term methods such as the use of plastic membrane exploit the land without caring for it. In fact, these methods destroy the land – and should be discontinued altogether.

Jiang Gaoming is a professor at the Chinese Academy of Sciences’ Institute of Botany. He is also vice secretary-general of the UNESCO China-MAB (Man and the Biosphere) Committee and a member of the UNESCO MAB Urban Group.

Now more than ever…

chinadialogue is at the heart of the battle for truth on climate change and its challenges at this critical time.

Our readers are valued by us and now, for the first time, we are asking for your support to help maintain the rigorous, honest reporting and analysis on climate change that you value in a 'post-truth' era.

Support chinadialogue

发表评论 Post a comment

评论通过管理员审核后翻译成中文或英文。 最大字符 1200。

Comments are translated into either Chinese or English after being moderated. Maximum characters 1200.

评论 comments

Default avatar
匿名 | Anonymous



Guiding instead of banning

In solving the problem of "white pollution", we should guide the public in using microorganism to break down plastic waste, instead of banning the use of high-tech products.

Default avatar
匿名 | Anonymous



We must start with ourselves.

To prevent this nightmare of having no usable infield from coming true, governments need to work closely with each other and back up their verbal commitment by actions. However, it is not enough only to ask what governments can do to get rid of white pollution, we must ask ourselves what we as individuals can do to colour the earth green instead of white.

Default avatar
匿名 | Anonymous



One question

Hi there, may I ask if the plastic membrane counts as white pollution?

Default avatar
匿名 | Anonymous





The relationship between White Pollution and Plastic Membranes

The majority of membranes used for farming have traditionally been made from plastic, a material which is not degradable. They are left in the ground for many seasons and so influence the quality of the soil, its water permeability, and so on. If the membrane is exposed to fire, it produces harmful chemicals which directly pollute the nearby soil, air, and water sources. Although new research is being done regarding degradeable membranes, the cost is steep. This issue really is a headache as our agricultural resources are already limited, and if we don't protect good soil, what will we eat in the future? Please would the author present their opinions to the relevant departments as much as possible.
Li Yang, Technical University of Munich.

Default avatar
匿名 | Anonymous


zhangftacz ([email protected]

To Mr. Jiang and those who love our land

There is a technology by the name of Imperforate Film Mulching Method for Crop Planting, simply as 'New Film Method', which can save arable land from white pollution. Nearly 20 years has witnessed the Chinese application of film mulching method, by which the topsoil is covered with plastic film in a way that both ends of the film, as a separator to keep the inside soil from the outside one, are buried perpendicularly into the soil, and through the opening on the film, the crops are planted. Because the film is buried too deep into the soil and entangles with the crop roots, it is hard to recycle them. In contrast, the imperforate film mulching method is a way to cover the topsoil with the film fixed by compacted soil on its ends when the crop is planted beside the film. By this method, the soil under the film is easy to keep moisture and heat, and is easy to absorb external moisture as well, which makes the crop growth not less than that by traditional mulching method. As the film is not buried deep into the soil, the crop and the film are separated from each other completely and the film can be all recycled, which stop the film from damaging the arable land while putting it in use. The film used in new film method is half of that in old method(half of the old film in width) with features of energy saving and emission reduction.


the rural pollution by film is grim after the old method being taken, and more than half of the used film being mixed with the soil year after year. the old method is gradually destroying the arable land we live with even though it brings current high yield, which is really a gain for now but a loss in future! the film dirties our land and space when farmers throw them onto the ground, ditches and ramps beside their farmland. These are places for wild plants like weed that fits for cows and goats, but they are now unavailable. The scene of film entangling with powerwires, tree branches, shrubs and straws is disgusting and astonishing! To raise the food production, governments promote the old method that Chinese farmers had no idea of using them at first, and this results in a rising yield followed by the horrible white pollution. comparing with the happiness of the rising production, we should pay more efforts to come true the harmony between man and nature, and cherish more the arable land we live by. the arable land is a life line not just for farmers but for the whole nation because our clothes and food are made from it. It is needed to promote the new film method the way the old method was promoted, as the old habit of taking the old method by farmers dies hard. It will take too long a time of decades or even half a century to spread the new film method nationwide if we let the method run its own promotion. In such a long time of self-promotion, the film pollution will do a damage we can not reverse! zhangftacz ([email protected]

Translated by Ming Li

Default avatar
匿名 | Anonymous


PE塑料农膜,可回收的PE 塑料农膜被堂而皇之的成为可降解薄膜,继续在农田里四处使用。
现在欧美国家都已经在致力推广100%生物可降解农用地膜的同时 ,中国上海还原高分子有限公司也将成为他们原材料的最大供应商,可是在国内,由于生产成本和价格因素,国内市场依然无法顺利打开局面。
只能用鲁迅先生的话说一句,人血馒头来治病,PE 环保塑料可降解农膜来种地一样。
sophia yeh [email protected]

The situation 3 years later

Dear Professor Jiang,
3 years have passed and, thanks to a friend's suggestion, I browsed the net and saw your farsighted critique. As we can note, the situation after 3 years sees Xinjiang dealing with water treatment problems as a consequence of the inappropriate use of plastic membranes in the fields. The recyclable PE plastic membrane used in agriculture will largely become biodegradable and continue to be used everywhere in the rural areas. Because of its cheap cost and the possibility to achieve more visible results, many peasants still employ this cheap plastic garbage, only to feel disgusted when they use it, nauseous when it reaches their guts. We always complain that today's tomatoes don't taste like tomatoes, today's cucumbers don't taste like cucumbers.
Up to now, this criticism hasn't spurred yet a proper strong guidance by the concerned departments. While Europe and America already devote themselves to popularize 100% biodegradable plastic for agricultural use, Shanghai Reduction of Polymer Materials Company Ltd. will become their main raw material supplier, but in China, due to the manufacturing costs and prices, the market is not ready for that phase yet. We can use Lu Xun's saying: just as human blood bread can cure illnesses, environmental protection PE biodegradable plastics can be used to cultivate.
China needs a popularisation of science, because the immoral conducts we find in the stupid manners of peasants or in the petty profit-lead unscrupolous merchants will destroy the fertile soil we can't live without. They need to be guided by scientific knowledge and authority organs.