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3. Basic Soil Monitoring and Evaluation
Discussion – Sampling Considerations
1.
Evaluate the following potential sampling strategies for their usefulness for assessing
a field’s nutrient availability.
A.
Sampling one shovelful from the surface in the center of the field
B.
Sampling three shovelfuls from the surface, all close to the center of the field
C.
Sampling three shovelfuls from the surface, at different locations around the field
D.
Sampling three shovelfuls from the surface and three from a set subsurface depth, all
close to the center of the field
E.
Sampling three shovelfuls from the surface and three from a single subsurface depth at
different locations around the field
F.
Sampling six shovelfuls from the surface and six from a single subsurface depth at
different locations around the field
G.
Sampling from different depths, but basing the samples on the soil’s O, A, B horizon
(see soil forming factors and the soil profile section on page 12)
Key questions to ensure that you get credible data:
•
Why are you sampling? What question(s) are you trying to answer?
•
Where and when are you sampling?
•
What are you sampling? What sampling protocol will you use? Do you have trained field
staff/appropriate sampling equipment? What lab/facilities can provide soil processing?
•
Do you have funding for sampling and processing?
•
Are you comparing information through time or across space to understand how
characteristics are or are not changing?
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Plan Your Monitoring and Sampling