Food & Climate 

Basics

1. Plants and Climate

Worksheet 3: Agriculture Simulation

Welcome to the Agriculture Simulation!

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The following simulation allows you to cultivate farmland and find out the yield of your crops.

1. Choose what you would like to plant in each field. You can either plant wheat (A), vegetables (B) or rice (C).

2. Decide whether the fields need watering or not.

3. Activate a random weather generator.  This controls what the weather was like in the spring before harvest time.  To do this you need to click on the green button at number 3 and click again to stop.

4. Click on the second green button, this gives you your crop yield per field and your overall total yield.

To restart the simulation, click on the green button with the arrow facing backwards.

Exercise: Try different settings.
Find out when the fields have the highest yield.

WARNING:

This is a ficticious model. Our model represents reality in a limited way:

- only some important factors are included
(neither "extreme drought" nor "pests")
- all results are given in a Model Currency
(not in Euros, and tonnes of yield are transfered into Currency)
- varying market prices are ignored
- the climate setting is Mediterranean with hot and dry summers
(and not for example a Monsoon climate)
- and there are further restrictions.

So what can you do with such a model?

- Test your hypotheses concerning growth conditions of different plants.
- Test the degree of irrigation needed by various crops.
- Optimise your yield.

Exercises:

- Find out which product needs irrigation.

- Which product depends heavily on irrigation?

- Which product could also be planted without irrigation? Under what conditions?

The following table will help you to do different experiments in a systematic way:

1. Table of experimental conditions

Animation by Julia Heres & Helmut Schrettenbrunner.

EXPLANATION OF THE SYMBOLS:

F1 = Field 1
F2 = Field 2
F3 = Field 3

A = wheat (production cost: 50)
B = lentil (production cost: 60)
C = rice (production cost: 1000)

=> fields NOT watered

=> fields watered (cost: 200 per field)

=> press random generator twice
     for weather conditions

=> shows the yield of each field and in total
      (in  Model Currency)

=> restarts the simulation

Correct or not correct?

After your experiments you should be able to answer the following questions about agriculture.
(remember that the simulation does not include all the factors which affect crop yield).

Click the green button, if you think the sentence is right and the red button if you think the statement is wrong.

1. You should plant rice in irrigated fields.

2. You must not irrigate the field if you plant wheat.

3. You should irrigate the field if you grow lentils.

4. If you plant rice you will have a good yield only if you irrigate the field.

5. Wheat yields are the same whether or not you irrigate the field.

6. If you grow lentils your yields will be higher if you irrigate the field.

7. After a very dry spring, wheat yields are below average if the field is not irrigated.

8. After a very dry Spring, the yield of rice on an irrigated field is below average.

9. After a very dry spring, lentil yields are below average if the field is irrigated.

10. If you have an average spring, the yield of wheat will be good even without irrigation.

Exercise:

Make a list of crops which need lots of water to grow well in a Mediterranean Climate.

Make another list of plants which can do with little water.

Find plants which are well adapted to the climate of your country.

Give reasons why this is so.

Model vs reality

1. Rice yields are high in the model so why doesn't the farmer just plant rice?

Rice needs lots of water to grow. In some areas it's not possible or cost effective to irrigate the land.  There might not be water close by or the field may be on high ground. Rice production is also very labour intensive, lots of people are needed to harvest it.

2. Why do farmers plant wheat when wheat yields are so low?

Wheat does not necessarily need irrigation.  Wheat production also needs fewer people as harvesting can be done using large combine harvesters.  So if labour is scarce but mechanisation is possible and large areas of fields are available, planting wheat is a good solution.

About this page:

author: Prof. Helmut Schrettenbrunner and Julia Heres - University of Nürnberg, Nürnberg, Germany
scientific reviewing: Dr. Elmar Uherek - Max Planck Institute for Chemistry, Mainz, Germany
last update: 2004-01-04