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Proper Sampling Techniqies
Proper Soil Sampling Techniques
1. Tools (Equipment) Use any of
the tools shown below, one or two clean pails and soil bags.
2. Sampling Depth
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• Surface soil samples from fields should be taken to a depth of
8".
• Subsoil samples should be taken from 8" to 36" for residual nitrate.
An alternative method would be to sample 8-24" and 24-48".
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3. Sample each field separately
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If cropping, fertilization and/or liming has not been uniform on
a field, then a separate sample should be taken from each management or soil area.
If fields are large, you may want to sample 40 acre units separately, but it is
not necessary if management has been the same and the soil type is the same. If
soil areas within a field are different in appearance (slope, drainage, color or
texture), each soil area should be sampled separately. Small areas may not need
to be sampled, but they will give some indication of the variation within the field.
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4. Composite surface
soil samples should consist of a mixture of about 15 soil cores. Composite
subsoil samples for the nitrate test should consist of 8-10 cores. Mix these core
thoroughly and fill the sample bag. Label the bag correctly and use this same identification
on the soil information sheet.
5. Sample separately or
avoid such areas as dead furrows, alkali spots and terrace channels.
6. Place soil information sheets in a plastic bag nd soil
samples as quickly as possible to our laboratory.
Feed Sampling Procedures
Hay
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Bales:
Sample at least 8 to 12 bales from each cutting or each lot. Core all rectangular
bales from the end and all round bales from the twine surface. Mix the samples thoroughly
and take a representative sample for analysis using the quartering procedure.
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Loose Hay Stacks:
Select 4 stacks from each cutting for sampling. Collect at least 3 core samples
from the side of each stack, mix thoroughly and take a representative sample for
analysis using the quartering procedure. If a core sampler is not used for hay sampling,
hand grab from each of the bales.
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Silage
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Upright silo:
Take random handfuls of silage while unloading. Mix the
samples thoroughly and take a representative sample for analysis using the quartering
procedure.
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Horizontal silo: Remove
a column 6 inches by 12 inches wide on the open end of the silo. Mix the sample
thoroughly and take a representative sample for analysis using the quartering procedure.
Bunk Sample
Take 6-8 grab samples from the bunk(s) as the ration is
being unloaded. Mix the sample thoroughly and take a representative sample for analysis
using the quartering procedure.
Grain Sample
Take 5 random hand samples from the bin or truck. Mix the
sample thoroughly and take a representative sample for analysis using the quartering
procedure.
Quartering Procedure
Sometimes when forages are sampled, the total of the aggregate
samples is to large and bulky to send in to the laboratory. The total sample size
can be properly reduced and still maintain a representative sample by quartering
the sample. Mix the entire sample thoroughly, then pour it into a pile on a clean
paper or plastic. Then divide the sample into four equal parts (quarters), saving
the opposite two quarters. If the sample is still to large, repeat the procedure
until the proper sample size of one pint to a quart is obtained. All samples should
be placed in an airtight plastic bag and submitted to the laboratory for analysis.
Plant Sampling Procedures
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Field Crops
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Stage of Growth
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Plant Part to Sample
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# of Plants
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Corn
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Seedling stage
(less than 12")
Prior to tasseling
Tasseling to early silking
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All above ground portion
Top leaf with collar
Ear leaf
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20-30
15-25
15-25
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Soybeans
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Seedling stage (less than 12")
Initial flowering
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All above ground portion
Uppermost fully developed trifoliate leaves
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20-30
20-30
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Small grain
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Seedling stage (less than 12")
Boot to heading
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All above ground portion
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50-100
20-30
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Hay, pasture or forage grasses
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Just prior to seed head emergence or 4 to 6 weeks after clipping
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All above ground portion
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20-30
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Alfalfa
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Bud stage to 1/10 bloom
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Upper 1/3 of plant
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15-25
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Milo
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Very early heading
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2nd leaf from the top
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15-25
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Water Sampling Procedures
1. Use a clean plastic container
for submitting your sample. Bottles can be obtained from the laboratory.
2. Rinse the container several
times with water that is being sampled. Send at least one-half pint of water to
be tested.
3. Wells should be pumped
several hours before sampling. Test wells should be sampled after pipe and screen
are in place. Pump well for at least 10 hours before sampling.
4. Samples of lakes, streams,
and ponds should be taken from below surface.
5. If it is not possible
to send the sample to the lab immediately after collection, refrigerate until it
is sent.
Bacteria Water Sampling Procedures
Please Read Carefully to insure accurate results.
1.
Samples will be accepted MONDAY THROUGH THURSDAY ONLY between
the hours of 8 a.m. to 3 p.m.
2.
Samples over 24 hours
old will not yield accurate results unless kept in refrigerated condition. Please
send as First Class or Priority Mail.
3.
The enclosed sterilized bottle contains
a small amount of preservative. If analysis is required in addition to Coliform,
a separate sampling bottle is required. (Please request a Water Testing Bottle).
4.
Collect sample from an indoor water
tap. Remove screen or strainer from spigot, (if one is present), and sterilize by
swabbing with rubbing alcohol. Allow water to run freely for FIVE MINUTES before
collecting sample.
5.
Avoid contaminating your sample.
Carefully remove lid from enclosed sample bottle without touching the inside of
the cap or threaded area of bottle.
6.
Do NOT rinse bottle. Fill bottle
to line. Replace lid at once.
If you have any questions please
call lab prior to taking sample at 1-308-234-2418.
Liquid Fertilizer Sampling Procedures
A critical requirement in getting a representative sample of a
liquid fertilizer is to take the sample directly from the main body of the material
without contamination. Avoid, whenever possible, taking samples from lines and valves.
Listed below are the preferred points of sampling in order of preference.
1. Directly from mixing
vat.
2. From the top opening
of storage or transport tank after agitating for 15 minutes.
3. From a delivery or recirculating
line after proper recirculation.
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