Cleaning up Chinese agriculture 化学农业威胁中国水资源

In 2007 about two million people were affected by a massive algal bloom that spread across Taihu, or Tai Lake, in eastern China. The government earmarked 100 million yuan (US$14.6 million) to clean it up.

The residents of Wuxi city, which straddles the lake, have a vivid memory of that hellish summer. Gallons and gallons of pollution from farms and factories – and even human sewage – had been pouring into the lake and triggered the giant bloom of blue-green algae. Drinking water turned green and fetid. The main source was fertilisers from farms. Billions of yuan have been spent to try to clean up the lake so far.

After the nightmare of 2007, was the lake any cleaner in 2008? Greenpeace went to investigate.

We were sad but not surprised to find that the lake was still smothered in algal blooms. In fact, the bloom began to appear even earlier than before.

And it is not just Tai lake. All sorts of water sources in China are being polluted this way. In Inner Mongolia in northern China, Wu Liangsuhai Lake is plagued by a serious yellow algal bloom. That bloom is also mainly caused by chemical fertilsers that are washed into the lake via irrigation. Chao Lake in Anhui province is also poisoned by this kind of pollution.

The government has made some effort to tackle pollution by encouraging ecological farming and recycling bio-waste. Since 2005, the Ministry of Agriculture has been promoting a nationwide reduction in fertiliser use and has been running a soil-testing program, where it advises farmers on what fertiliser is needed according to the state of the soil with the aim of preventing overuse. In the three years of soil testing from 2005 to 2007, some 90 million mu (60,000 square kilometres) of farmland has been tested.

From March to November 2008, Greenpeace ran tests on the water in Taihu to see if there had been any reduction in the amount of fertiliser pollution. We collected water samples from streams that run from nearby fields into the lake. We also interviewed farmers and recorded how much fertiliser they were using, what kind of fertiliser and when they used it. We tested the 25 water samples for nitrogen, nitrate and phosphor content.

Our investigation reveals just how polluted the water still is despite three years of government efforts.

The concentration of total nitrogen (TN) exceeded the national standard V in 20 of the 25 samples and exceeded the national standard IV in the remaining five. All of the samples are not fit for human use, drinking or otherwise. Water samples that do not meet standard V cannot even be used for industrial or agricultural use.

Nitrate – which comes from fertiliser – was also found in high concentrations. The results indicate that chemical fertilisers are still a major source of pollution in the Tai lake. Farmers also told us that over the past 10 years they have increased their use of fertilisers.

Agricultural pollution is a huge challenge for Wuxi and for many other parts of China. In the three years of national soil testing from 2005 to 2007, the total amount of fertiliser use in China increased by about two million tonnes every year (see Table 1). At the same time, fertiliser production also increased.

Table 1

While the government has been pouring money into cleaning up Taihu, little has been done to solve the problem at source. The solution is a major move from chemical intensive agriculture to eco-farming.

A perfect example of how eco-farming can work well in China is in a beautiful village in Yixing municipality, just west of Taihu. There, some 200 mu (133,300 square metres) of paddy rice fields are farmed with the help of an army of ducks. The rice-duck system is a very successful eco-farming method. Ducks eat pests and weeds, meaning little or no pesticides or herbicides need be used. By paddling around the paddies, they help to stir up nutrients in the water, helping the rice plants grow stronger without the use of chemical fertiliser. Organic fertiliser and duck waste can also add nutrients.

There are many other eco-farming methods which can help farmers grow a successful harvest without using polluting chemicals and poisoning the environment.

The soil testing program, which still recommends chemical fertilisers to farmers, eco-farming promotes the use of organic fertilisers including the recycling of agricultural “waste”, such as straw and animal manure.

The government has drawn up policies to promote eco-farming, but we believe these should be strengthened. More money and greater support should be offered to help farmers switch methods.

The government should also review its soil testing program, as it still relies on chemical fertilisers. We also urge the government to limit the amount of chemical fertiliser produced in the country including the removal of subsidies to this sector.

We also believe that more policies are needed to encourage recycling, the production and efficient use of organic fertilisers.

There is no time to waste. The pollution of China’s water systems has reached a crisis point. China needs change.

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2007年在中国东部的太湖发生的大规模蓝藻爆发使两百万人受到了"饮用水危机" 的影响。流入太湖的大量“营养”污染物（氮、磷等）造成了蓝藻严重爆发，使无锡人的水龙头中流出带着腥臭味的绿色的水。这些流入太湖的污染物来自于农业、工业以及生活废水。其中，大量施用在农田里的化学合成肥料是“主犯”之一。这次水危机让无锡人深刻体会到了太湖污染的后果。历年来，政府对太湖污染的治理已经投入了几百亿的资金，2008年，太湖的情况又是如何呢？这一年，太湖蓝藻卷土重来，甚至比往年发生的更早。当绿色和平的工作人员看到太湖的蓝藻时，我们感到很痛心，但是并不意外。

学农业（以来大量化学合成肥料和农药投入的农业生产方式）相关的藻类爆发事件不仅仅影响了太湖，也影响了中国其他地区的重要水系。例如：2008年6月，黄河流域最大的淡水湖——内蒙古乌梁素海——发生了严重的黄藻爆发，根本原因是河套平原灌区农田中流失的大量化肥，通过排干渠系统不断汇入乌梁素海造成的污染；安徽巢湖也是备受化学农业污染困扰多年的一个重要湖泊。

相关政府部门已经设计和实施了多项政策以应对农业污染。比如：鼓励生态农业，循环利用农业废弃物。另外，农业部从2005年开始推行一项全国性的化肥减量政策——测土配方施肥 ，项目实施三年后，全国已累计推广测土配方施肥面积达9亿亩次。

绿色和平在2008年3月至11月期间在太湖周边进行调查，以检验测土配方施肥在这一区域减少化肥用量、控制农业污染方面的进展。调查中，绿色和平的工作人员在直接流入太湖的两条小河采集了25批次水样，并访问了当地农民，记录他们施用化肥的时间、种类和用量。水样被送往实验室，检验其中与化学农业相关的总氮、硝态氮、总磷等物质含量。

水样检测结果显示，当地在开展测土配方施肥工作3年后，水污染依然严重。

20批次样品中的总氮浓度超过国家地表水Ⅴ类标准，其余5批次水样超过Ⅳ 类水标准。这就意味着水样采集地的水不能作为饮用水源地，也不适宜人体直接接触。超过Ⅴ类水标准的水，甚至不能用于工业生产和农业灌溉。硝态氮主要来自于化肥流失，水样检测结果显示在施用化肥后，由于降雨或者灌溉的冲刷作用，使水中含有高浓度的硝态氮。检测结果说明，化肥流失造成的农业污染仍是一个主要污染源。农民们也正是，他们的化肥施用量几乎比十年前增加了一倍。

太湖的农业污染仍旧是对无锡的一个威胁。农业污染，同样也是中国其他地方存在的问题。在2005年至2007年，测土配方施肥实施的三年中，每年的全国化肥施用量都要比上一年增加近200万吨（见下图）。与此同时，中国的化肥生产量也一直在上升。测土配方施肥项目开始于2005年，但是并没有给中国的化学合成肥料施用量带来拐点。大量的化肥仍旧在源源不断地进入水中造成污染，并最终危害人类自身。

当政府投入大笔资金清理藻类时，真正的解决之道——生态农业——却没有得到足够的推广。

在太湖西岸的宜兴，有一个坐落在山脚下的美丽的村子。那里有200亩由“鸭子军团”守卫的水稻田。“稻田养鸭”是一种典型的生态农业模式。鸭子在稻田中放养，它们吃掉稻田里的害虫，杂草也被踩死或者吃掉。鸭子的游动将更多的氧气带入水中，让水稻长得更加强壮。有机肥和鸭粪为水稻提供了足够的营养。化学合成肥料和农药不再是必需品。

与“稻田养鸭”类似，还有很多种不同的生态农业模式可以让农民收获充足、安全的粮食，而且不必以破坏环境为代价。与测土配方施肥相比，生态农业不依赖化学合成肥料，而是充分利用牲畜粪便、秸杆等农业“废弃物”制造有机肥料和沼气。尽管已经有一些旨在推动生态农业的政策，但这些政策的内容和执行仍需细化和加强。需要有更多的财力、物力和人力支持生态农业的推动，让农民、消费者、环境都从中受益。

中国政府急需对测土配方施肥的效果重新进行评估，因为这项政策只是针对化肥使用者（农民）的，而且仍旧是以依赖化学合成肥料投入为基础。如果政府想要切实减少化肥的施用量，就需要制定针对化肥生产者的生产减量政策，这其中可以包括减少对化学合成肥料的生产补贴和优惠。另外，还需要制定一系列鼓励有机肥生产、推广和高效利用的激励政策。

没有更多的时间可以浪费了，中国农业急需从根本上转变农业生产方式。