Feed the world: artificial nitrogen fertilisers

The problems caused by artificial fertilisers have had a fair amount of media coverage in recent years. Should we still use them? Should we all ‘go organic’? What is best for the environment? What sustainable solutions are there to the problems associated with growing food?

This activity allows students to consider the benefits and drawbacks of using artificial fertilisers and encourages them to do so from a scientific, rather than an emotive point of view. Students will probably bring their own existing ideas and beliefs to the activity and they should be encouraged to think about whether the scientific data supports their views.

Overview

Students take on the roles of a number of experts. Some information is provided for each role and students can do their own research to find out more about the likely views of the expert they are playing.

One of three routes can be taken through the activity:

1. If video cameras are available, students could make a TV programme. This could either be done in the form of a TV debate in the style of programmes like ‘Question time’, or ‘Richard and Judy,’ or it could be a mini documentary in the style of ‘Panorama,’ ‘Horizon’ or another similar programme. Students would need to be in reasonably large groups and the activity would need careful management.
2. Alternatively, the whole class could prepare for a radio show on the subject. The final show will require a presenter with a reasonable grasp of the arguments both for and against the use of artificial fertilisers, three experts on each side of the debate and a group of listeners. Divide the class into seven groups to prepare for the show and give each group the information sheet for one of the possible roles.

Students should then discuss the information and the views their character might hold. Each group must nominate a spokesperson to take the role of the presenter or one of the experts in the final show. The remainder of the class becomes the listeners, who can phone the radio station during the show to state their opinions. You could use a microphone to aid management of the discussion – students are only ‘on air’ when speaking into the microphone and must remain silent otherwise.

It is important that a strong student plays the role of the presenter, who should hold the experts in line, take calls and facilitate discussion. If your presenter group is struggling with preparing for this role, you could discuss some of the arguments they might hear from the other students with them before the show starts.

Student sheets required:

• Feed the world – general briefing sheet (TV)
• Feed the world – general briefing sheet (radio)
• Expert briefing – presenter
• Expert briefing – farmer
• Expert briefing – spokesperson for the charity ‘Food for All’
• Expert briefing – spokesperson for the charity ‘Action on Habitat Destruction’
• Expert briefing – ‘Organic Food Producers and Consumers Association’
• Expert briefing – ‘Green Earth’ environmental charity
• Expert briefing – ‘Water Quality Campaign

The teacher takes the role of the producer of the show, supporting the presenter in managing the discussion and taking calls.

3. Another alternative is to ask students to do some research then hold a class debate about the issues involved.

Experts

Neutral

• Presenter

For artificial fertiliser use

• Farmer
• Spokesperson from the charity ‘Food for All’
• Spokesperson from ‘Action on Habitat Destruction’

Against artificial fertiliser use

• Spokesperson from the ‘Organic Food Producers and Consumers Association’
• Spokesperson from ‘Green Earth’ environmental charity
• Spokesperson from the ‘Water Quality Campaign’ group

Each student will need a copy of the General briefing (either the TV or the radio version as appropriate) and a copy of the Expert briefing for the group to which they have been assigned.

The General briefing includes some suggested websites for further research.

Note

Remind students that this debate/TV or radio programme is about fertilisers and not about the use of pesticides, antibiotics or genetic modification. If they do their own research to add to the information supplied in the notes they are given, then they should make sure they stick to the main point of the debate, ie ‘Should we use artificial fertilisers?’

Follow-up

After the debate, each student could write a newspaper or magazine article about the issues raised.

They should include arguments from both sides of the debate, as well as their own opinions A more able group could be asked to research and present ideas for sustainable solutions to the problem of feeding 10 billion people.

Possible starting points could include the websites listed on the General briefing sheet and perhaps also the following site: http://www2.essex.ac.uk/ces/default.htm#top (accessed December 2005) – students will need a high level of reading and comprehension skills to use this site but it contains a lot of useful information.

Less useful agriculture If students are up in arms at the environmental damage agriculture is causing, you may wish to point out that tobacco is also produced on farms. These farms cause habitat destruction and pollution from fertilisers and the final product does not even feed anyone!

Briefing sheet examples

Expert briefing – presenter

You are the presenter of a television programme or radio phone-in show. You will need to interview each of your six expert guests, three of whom are for the use of artificial fertilisers and three of whom are against it. 

When the experts have made their presentations/answered your questions, you will take questions and comments from your listeners, who will phone in. Your job is to keep the show interesting and informative, to allow those who wish to speak to do so – one at a time – and to keep the discussion based on the central question: ‘Should we use artificial fertilisers?’

Your aim is to make a programme that will demonstrate the benefits and the drawbacks of using artificial fertilisers and will allow listeners to hear a balance of arguments so that they can make up their own minds on the issue. You should have an idea of the main arguments you think the six experts might make prior to the show.

Prepare some suitable questions to ask them.

Expert briefing – farmer

You are a farmer and your aim is to make a living from your land. To do this you need to grow crops, harvest them and sell them at a fair price. You also need the land to remain in good condition or else you will not be able to make a living year on year.

Some points you might want to make

• If you do not put fertiliser of any kind on your land, it will eventually produce low yields and poor quality crops.
• Fertiliser costs money so you do not want to use a lot more than you need. 
• Some of the fertiliser will leach into rivers and streams, but this also happens when natural fertilisers such as manure are used.
• Experiments done at research farms have shown that it is essential to use some kind of nitrogen-containing fertiliser to maintain high yields of crops but it makes no difference to the plants whether the fertiliser is natural or artificial.
• Research has also helped tell farmers when is the best time to put fertiliser down and how much should be used – this has helped reduce the amount of excess fertiliser used by one third compared to 20 years ago and leaching has been reduced by one fifth.
• Everyone eats the food produced on farms and it is not possible to produce food without causing some change to the environment. 
• If we tried to convert all the farms in the world to ‘organic’ farming and they all used manure as fertiliser, we would need to have a lot more cows to produce all that manure – the number would need to increase from about 1.5 billion to 6 or 7 billion, which would cause environmental damage by overgrazing, erosion and destruction of wildlife habitats (and it would smell really awful!).

Expert briefing – spokesperson for the charity ‘Food for All’

The aim of ‘Food for All’ is to ensure that every person on the planet has enough to eat. Some points you might want to make

Prior to the introduction of fertilisers in Europe, famine was all too often a problem and people starved to death. The most recent European famine was in the 1850s and many people died. After that, various sorts of fertiliser were introduced, which helped to prevent the problem.

• There are 800 million malnourished people in the developing world. 
• Today there are about 1.5 billion hectares of farmland worldwide. Using pre-20th century agricultural practices – so no artificial fertilisers – this land could be made to feed about 3.2 billion people.
• There are 6 billion people in the world today so without fertilisers we could only feed just over half of them – and this with a basic, mainly vegetarian diet.
• So, about 40% of the world’s population is dependent on artificial nitrogen fertilisers and would starve to death without them.
• If there was an even distribution of food all round the world and everyone adopted a simple but adequate diet of mainly cereals and legumes (beans and peas) we could all survive – even if harvests were a bit lower than they are today. Even in the very unlikely event that this were done, we would still be dependent on artificial fertilisers for about 1/3 of our food.
• The world population is still rising and is likely to reach around 10 billion in the next 100 years.
• We may not like it, but we are dependent on nitrogen fertilisers to survive.

Additional briefing sheets can be found in the downloadable content below.