引言

In Paris, urban farmers are trying a soil-free approach to agriculture that uses less space and fewer resources. Could it help cities face the threats to our food supplies?

第1段

On top of a striking new exhibition hall in southern Paris, the world’s largest urban rooftop farm has started to bear fruit. Strawberries that are small, intensely flavored and resplendently red sprout abundantly from large plastic tubes. Peer inside and you see the tubes are completely hollow, the roots of dozens of strawberry plants dangling down inside them. From identical vertical tubes nearby burst row upon row of lettuces; near those are aromatic herbs, such as basil, sage and peppermint. Opposite, in narrow, horizontal trays packed not with soil but with coconut fibre, grow cherry tomatoes, shiny aubergines and brightly coloured chards.

第2段

Pascal Hardy, an engineer and sustainable development consultant, began experimenting with vertical farming and aeroponic growing towers – as the soil-free plastic tubes are known – on his Paris apartment block roof five years ago. The urban rooftop space above the exhibition hall is somewhat bigger: 14,000 square metres and almost exactly the size of a couple of football pitches. Already, the team of young urban farmers who tend it have picked, in one day, 3,000 lettuces and 150 punnets of strawberries. When the remaining two thirds of the vast open area are in production, 20 staff will harvest up to 1,000 kg of perhaps 35 different varieties of fruit and vegetables, every day.”We’re not ever, obviously, going to feed the whole city this way,’ cautions Hardy.’In the urban environment, you’re working with very significant practical constraints, clearly, on what you can do and where. But if enough unused space can be developed like this, there’s no reason why you shouldn’t eventually target maybe between 5% and 10% of consumption.’

第3段

Perhaps most significantly, however, this is a real-life showcase for the work of Hardy’s flourishing urban agriculture consultancy, Agripolis, which is currently fielding enquiries from around the world to design, build and equip a new breed of soil-free inner-city farm.”The method’s advantages are many,’ he says.”First, I don’t much like the fact that most of the fruit and vegetables we eat have been treated with something like 17 different pesticides, or that the intensive farming techniques that produced them are such huge generators of greenhouse gases. I don’t much like the fact, either, that they’ve travelled an average of 2,000 refrigerated kilometres to my plate, that their quality is so poor, because the varieties are selected for their capacity to withstand such substantial journeys, or that 80% of the price I pay goes to wholesalers and transport companies, not the producers.’

第4段

Produce grown using this soil-free method, on the other hand – which relies solely on a small quantity of water, enriched with organic nutrients, pumped around a closed circuit of pipes, towers and trays – is ‘produced up here, and sold locally, just down there. It barely travels at all,’ Hardy says.”You can select crop varieties for their flavour, not their resistance to the transport and storage chain, and you can pick them when they’re really at their best, and not before.’No soil is exhausted, and the water that gently showers the plants’ roots every 12 minutes is recycled, so the method uses 90% less water than a classic intensive farm for the same yield.

第5段

Urban farming is not, of course, a new phenomenon. Inner-city agriculture is booming from Shanghai to Detroit and Tokyo to Bangkok. Strawberries are being grown in disused shipping containers, mushrooms in underground car parks. Aeroponic farming, he says, is ‘virtuous’. The equipment weighs little, can be installed on almost any flat surface and is cheap to buy: roughly 10o to 15o per square metre. It is cheap to run, too, consuming a tiny fraction of the electricity used by some techniques.

第6段

Produce grown this way typically sells at prices that, while generally higher than those of classic intensive agriculture, are lower than soil-based organic growers. There are limits to what farmers can grow this way, of course, and much of the produce is suited to the summer months.‘Root vegetables we cannot do, at least not yet,’ he says.’Radishes are OK, but carrots, potatoes, that kind of thing – the roots are simply too long. Fruit trees are obviously not an option. And beans tend to take up a lot of space for not much return.’ Nevertheless, urban farming of the kind being practised in Paris is one part of a bigger and fast-changing picture that is bringing food production closer to our lives.

引言

在巴黎，城市农民正在尝试一种无土农业的方法，它所需要的空间更少，资源消耗更少。这种方法能否帮助城市应对我们食品供应的威胁呢？

第1段

 在巴黎南部一座引人注目的新展览馆的顶部，全球最大的城市屋顶农场开始见效了。小巧、味道浓郁、色彩艳丽的草莓在大型塑料管内大量生长。往里面看，你会发现这些管子完全是空心的，几十棵草莓悬挂在管子内的根部。在附近的相同垂直管中，密密麻麻地种满了一排排的莴苣；在莴苣旁边是香草，如罗勒、鼠尾草和薄荷。相对的，在狭窄的水平托盘中，不是装满土壤，而是椰纤维，生长着樱桃番茄、光滑的茄子和色彩鲜艳的甜菜。

第2段

帕斯卡·哈迪是一名工程师和可持续发展顾问，五年前开始在巴黎公寓楼的屋顶上尝试垂直农场和空气动力学种植塔。这些无土塑料管被称为垂直农场和空气动力学种植塔。这个位于展览馆上方的城市屋顶空间相当大，有14,000平方米，几乎与两个足球场的大小相同。已经有一支年轻的城市农民团队负责管理，他们在一天内采摘了3,000颗生菜和150个盒装草莓。当剩下的三分之二广阔的开放区域投入生产时，将有20名员工每天收获多达1,000公斤的大约35个不同品种的水果和蔬菜。”显然，我们不可能完全用这种方式来养活整个城市，”哈迪警告道。”在城市环境中，你在处理什么可以做和在哪里做方面会遇到很多实际限制。但是如果能够开发足够多的未使用空间，没有理由不能最终目标将消费量的5%到10%供应。”

第3段

这是Hardy兴旺的城市农业咨询公司Agripolis的真实展示场所，该公司目前正接到来自世界各地的咨询，以设计、建造和装备一种新型的无土内城农场。Hardy表示：“这种方法的优势很多。首先，我不太喜欢我们吃的大部分水果和蔬菜被处理了大约17种不同农药，或者那些产生大量温室气体的密集农业技术。我也不太喜欢它们平均行驶2000公里，通过制冷方式运输到我的餐盘上，它们的质量很差，因为这些品种被选中是为了能够经受如此长途的旅程，而我支付的80%价格并不流向生产者，而是流向批发商和运输公司。”

第4段

使用这种无土栽培方法种植的农产品，完全依赖于一小量富含有机营养物质的水，在一个封闭的管道、塔和托盘回路中循环泵送。哈迪说：“这些农产品在这里生产，在本地销售，几乎没有运输。”你可以选择农作物品种以追求口味，而不是考虑它们对运输和储存链的抵抗力，你可以在它们真正最佳状态时进行采摘，而不是提前采摘。土壤得以保持不耗竭，每隔12分钟为植物的根部轻轻淋浴的水被回收利用，因此这种方法在相同产量下比传统的农场节水90%。

第5段

 城市农业当然并不是一个新的现象。从上海到底特律，从东京到曼谷，都出现了城市内部的农业蓬勃发展的情景。草莓在废弃的货柜里被种植，蘑菇在地下停车场中生长。他说，气雾栽培是一种“高尚的”方式。这种设备重量轻，几乎可以安装在任何平坦的表面上，并且价格便宜：大约每平方米100到150美元。运行成本也很低，消耗的电力只有某些技术使用量的一小部分。

第6段

  以这种方式种植的农产品通常以相对于传统的集约农业来说更高的价格销售，但比基于土壤的有机农业的价格要低。当然，农民在这种方式下所能种植的作物是有限的，并且大部分的农产品只适合夏季生长。“根类蔬菜我们目前还无法种植，至少还不行。”他说，“萝卜可以，但胡萝卜、土豆等根类蔬菜的根太长了。显然，水果树也不是一个选择。而且豆类占用的空间较多，回报却不是很大。”然而，巴黎正在实践的这种城市农业只是整体快速变化中的一部分，使食品生产更加贴近我们的生活。