SOIL SAMPLING

SOIL SAMPLING

It involves taking a portion of soil from the field as a representative of the whole field to the lab to be analyzed.

To analyze is to find out more about something.

Importance of soil sampling

1. To know nutrients present in the soil, those which lacking and therefore decide on what fertilizers to use.
2. It helps to know the soil PH and therefore decide which crop has a narrow PH range in which it grows best.

Tools used in soil sampling

Soil auger

It is used to determine the depth from which a soil sample can be allocated.

Gardener’s Trowel

It is used to obtain a thin slice of soil.

Hand hoe

It is used to clear away the surface vegetation and in the absence of the oil auger it can also be used to obtain a soil sample from the required depth.

Shovel

Spade

They are used to put away surface vegetation and also used to get the soil.

Procedure W

• Identify the field from which a soil sample is going to be taken and this shouldn’t be larger thatn5 hectares.
• Choose 20 places from this field from where the soil will be taken. The 20 places can be chosen using two (2) methods

Random method

The 20 places should be a fair representation of the whole field therefore they should never be from below old manure piles.

• Trenches
• Under trees
• Ant hill
• Below stone piles
• Previously burnt areas.

Clear the surface vegetation away using either therefore the spade r the shovel.

Make a hole of convenient side with one side vertical.

Determine the depth from which you are going to get the soil sample using the soil organs. This should be 15cm, if you don’t have the soil organ you mark off 15cm on the hoe.

Get a thin slice of using either the trowel, spade or shovel and put it in the sampling bag.

Do the same from the other 10 places.

Mix the soil thoroughly in the sampling bag.

Sub sample the soil by spreading it out well on top of the taple, divide it into 4 quarters, through away the diagonal quarters, spread out the remaining soil, repeat dividing into quarters and throwing away the diagonal ones until you are remaining with the remaining ones.

When you are remaining with a small sample put it in a container and label.

The name of the label should have name of the person who took the soil sample location where the sample was taken, nature of vegetation, date when the sample was taken.

The container of the soils taken to the lab were it is analyzed for the following;-

• Nutrient content
• Organic matter content
• Water content
• Air content
• Rate of capillarity
• Soil PH

N.B

It is important to observe the following when taking a soil sample:-

• All equipment used should be clean
• The person taking the sample should have clean hands.
• If you are a smoker do not smoke as you take the sample as this will bring chemical contamination.