Mining plantsThese scientists have discovered that there are about 700 plants that flourish in metal-rich soils. Their roots suck the metals out of the ground and store them in their sap, stems and leaves. Antony van der Ent is experimenting with macadamia trees, known for accumulating manganese. Dr Baker and some of his colleagues, for their part, are experimenting in a vegetable plot in Malaysia with plants that accumulate the metal nickel. Every few months a farmer harvests part of the plants and, using a simple process, extracts the metal. Nickel is particularly interesting, as two-thirds of metal-loving plants feed on nickel. Scientists like van der Ent and Baker hope that, in a few years, a part of global demand for certain metals and minerals will be supplied by this kind of agriculture. They imagine a future where farmers can farm fruit and vegetables as well as minerals and metals.
The problems with traditional miningThis is particularly important because there is an increasing demand for certain materials. Nickel is a key element in stainless steel. It is also used in the green economy, to make batteries for electric cars, for example. But the traditional mining of nickel is not an environmentally friendly activity. Mining destroys vegetation in and around the mine. The soil that is dug up is easily eroded and often ends up washed into rivers and seas, causing damage to the local flora and fauna. Furthermore, there have been many cases of water and soil contamination caused by the chemicals used in the nickel mining processes. Mining other metals and minerals also presents similar problems. Furthermore, mining is a hard, dangerous job – miners are often involved in serious accidents.
Prospects for the futureNone of these problems would exist in agromining. Scientists like Dr Baker believe that hyper-accumulating plants could even reduce the environmental costs of traditional mines. In fact, these plants could be grown on old, closed mines: they would extract the remaining metals left in the soil, stop erosion and begin reforestation. Also, agromining could be done in metal-rich soils that are toxic for normal agriculture. It could also be the perfect solution for bringing vegetation back to deforested areas. It would make agriculture possible in what are now poor, deserted areas and provide farming jobs to local populations. Agromining could also serve the medical industry, says Dr van der Ent. There are plants that collect zinc and selenium, for example, which can be used to make food supplements. Perhaps only this is old news: we already know we need to eat vegetables to obtain important metals and minerals. What might be new, in the future, is that we will be cooking and eating those farmed vegetables with cookware and cutlery partly produced with farmed metals.
USEFUL LINKS 1) Read more about agromining here: https://www.abc.net.au/news/2021-04-09/trees-that-bleed-metal-could-help-power-the-future/100051066 https://www.nytimes.com/2020/02/26/science/metal-plants-farm.html 2) Watch this interview with Dr Antony van der Ent talking about hyper-accumulating plants: https://www.youtube.com/watch?v=GcLH6WxkVkI 3) Here is an animated video explaining how and why some plants love nickel: https://www.youtube.com/watch?v=L89sLg4H4BA 4) How are metals extracted from plants? Here is a project of the Université de Lorraine explaining how it is done: https://life-agromine.com/en/388-2/ 5) Did you know that some plants can also purify the air, absorbing harmful pollutants? NASA did an interesting study to discover which plants are most effective at this: https://www.youtube.com/watch?v=lPNYdSZRSdg https://en.wikipedia.org/wiki/NASA_Clean_Air_Study
COMPREHENSION 1) Read the article and cross out the WRONG alternative (two answers are correct and one is incorrect). 1. Traditional mining includes___ (Carlo Dellonte) (Image credits: Wikimedia Commons, Wikimedia Commons)
- surface mining.
- underground mining.
- improve traditional mining.
- find alternatives to traditional mining.
- substitute excavators with plants to obtain metals.
- roots that suck the metals out of the ground.
- leaves that absorb metals from the air.
- sap that contains metals.
- perfect for a small number of plants.
- toxic for most plants.
- ideal only for macadamia plants.
- a very large number of metal-loving plants feed on nickel.
- there is a great demand for nickel, for example, in the green economy.
- nickel is environmentally friendly.
- it harms local plants and animals.
- it’s an expensive activity.
- it can pollute water and soil.
- requires just as much digging.
- is less dangerous for the workers employed.
- is less harmful for the environment.
- clean old mines.
- introduce farming where it was not previously possible.
- replace traditional agriculture.
- new jobs.
- metal rich soils.
- materials to make everyday objects.
- already used on a large, industrial scale.
- still in its infancy.
- the potential solution to many problems.