284 Sustainable Farming
Learning about soil
Purpose: This activity helps show how
different farming practices affect the soil
Time: 3 hours
Materials: digging tools, 3 boards or pieces of
cardboard, water, paper, and a pencil or marker
➊ Choose 3 parcels of farmland that have
been used in different ways.
For example, choose a field of maize
or dry farmed rice, an orchard or home
garden, and a plot that has been used for
pasture for many years. The plots should be
within easy walking distance from each other.
➋ With a group of farmers, walk through each of the areas. Cross back and forth,
looking at everything that may have affected the soil. What signs show how the
land has been used? Are there signs of erosion (for example, gullies, bare or rocky
spots of ground, richer soil at the bottom of hills than at the top)? Do the plants
look healthy?
➌ Talk to the person who farms each area to find out what practices they have used
over the past 5 to 10 ten years. Do the group’s observations match what you learn
from talking to the farmers?
➍ Dig a small pit about 50 cm deep in each parcel. Cut 1 wall of the pit so that it is
straight down and flat. Using a flat shovel or a long machete cut a slice about
3 cm thick from the flat side of the pit. Lay this slice of soil gently on a board or flat
surface. Label the soil sample to identify which parcel it came from.
➎ When you have taken soil samples from all 3 areas, bring them to a meeting place
where the group can examine them. What differences are there between the
different soil samples? Look closely for differences in color, texture, structure, smell,
and the presence or absence of worms and insects. Perhaps taste a small bit of
each soil to compare the pH. Is it sweet or sour? Have different people take a little
soil in their hands from different samples. Work in a small amount of water to each
and say if it feels sticky, rough, smooth, or falls apart.
➏ Discuss which of these differences may have been caused naturally by wind and
weather, and which may have been caused by the way the land was used.
Using knowledge from the group, from this book, or from other sources, discuss
ways to protect and improve the soil in the areas that will be used for farming.
These ways may include adding natural fertilizers (see pages 285 to 289), protecting
the soil from erosion (see pages 289 to 293), using sustainable grazing practices for
livestock (see page 307 to 308), and trying other farming practices.
A Community Guide to Environmental Health 2012