Golden Nematode Program Manual - Phytosanitary Resources

Procedures: Survey
Systematic Manual Soil Sampling
Simplified 8-by-8 Block Sampling Method
The simplified 8 x 8 sampling may also be used. Instead of dividing the
survey field into blocks, distribute the collection bags along the edge of
the field at intervals in multiples of 8 paces, so that each will cover as
close to a half-acre as possible.
EXAMPLE
For a field approximately 450 paces long, pacing the length of the field one
time (one trip) and taking a soil sample (one scoop each 8 paces) yields one
sample (8 paces per scoop = 56 scoops per sample).
The advantages of the simplified 8-by-8 Block Sampling Method are:
(1) carrying the extra weight of several soil samples while completing
the last is not necessary; and (2) indicating the location of samples is
simpler (show where the first and last samples were taken and the
width between sample lines).
Modified 8-by-8 (4-by-8) Block Sampling Method
The modified block sampling method (4 x 8) is a variation of the
standard 8-by-8 grid pattern. This modified method increases the
sensitivity of the survey by doubling the number of sample points, and
does not generate any additional samples per acre. Using the modified
8-by-8 (4-by-8) block sampling method, a complete sample will consist
of 112 sample points.
The general procedure for the 4-by-8 modified sampling method is the
same as the standard 8-by-8, except a sample is collected every 4
paces instead of every 8 paces.
Follow the steps below:
1. Divide the field into units.
2. Determine the number of bags needed in the first tier (length of
an edge of the field in a straight line).
A. Pace the length of the field.
B. Divide the number of paces by 224. This gives you the
number of sample bags required for each tier. If the
remainder is over 80 paces, then add an additional bag to the
tier.
C. Place the sample bags for the first tier, then take 16 paces
and place the sample bags for the second tier, and continue
pacing and placing bags for each consecutive tier.
D. If the last tier is less than 16 paces wide, then each soil
sample bag for this tier will cover an area approximating the
square area covered by the standard bags in the other tiers.
2-3-6 Golden Nematode Program Manual 11/2007-01
PPQ