Better Farming Series 14  Farming with Animal Power (FAO  INADES, 1977, 57 p.) 
Choosing and preparing fields 

A good field must have its proper boundaries. Before preparing your field, mark out its boundaries.
You will need to know how to measure your field.
Example: You want to make a field of 1 hectare.
Field of 1 hectare
This field should be either square or rectangular. This means that its corners must be right angles.
How to make a right angle
The corner of a is book let is a right angle.
Measure 4 metres along side OA and 3 metres along side OB.
Now the length of AB should be 5 metres.
Right angle
Why make a field with right angled corners?
It is easy to calculate the area of such a field.
You can reckon better the density of sowing (see Booklet No. 1, page 26).
You know how much fertilizer to apply.
You know whether the field yields a good or a poor harvest.
· It is easier to till with animals.
HOW TO CALCULATE THE AREA OF A FIELD
To calculate the area of a field with right angles at the corners, multiply the length by the width of the field.
Example: a field is 100 metres long and 100 metres wide; its area is 100 x 100 = 10000 square metres (m²).
A square metre is a square measuring 1 metre in length and 1 metre in width.
One hectare = 10 000 m²
Example: a field is 200 metres long and 50 metres wide; its area is 200 x 50 = 10 000 m² . It is aIso 1 hectare.
A field
Two fields of 1 hectare
A field which is 71 metres long and 71 metres wide has an area of 71 x 71 = 5 041 m²,
A field which is 100 metres long and 50 metres wide has an area of 100 x 50 = 5 000 m²
These are both fields of half a hectare.
In order to work with animal power: