(introduction...)

· To live, a plant needs water
(see Booklet No. 2, page 26).
When plenty of rain falls, the harvest may be good.
But when very little rain falls, the harvest is bad.
To get a good harvest, there must be enough water.

· A plant needs water every day.

But it does not rain every day.
When it does not rain, the plant must be able to find water in the soil.
Thus the soil must build up reserves of water.
Good soil builds up reserves of water and gives it back to the plant when necessary.

Good soil builds up reserves of water and gives it back to the plant when neccesarry