Soil sampling is important to measure nutrient levels in fields and determine optimal fertilization plans. There are several sampling strategies including random sampling, grid sampling, soil series, and topographic unit sampling. Random sampling selects cores randomly while grid sampling divides the area into sections. Soil series sampling composites multiple single samples to profile nutrient levels in different areas. Topographic unit sampling accounts for natural variations in slopes, elevations, and depressions. Samples should be collected 3-6 months before planting and do not need to be taken every year. Proper sampling involves mapping areas, collecting 5-10 spot samples per area, compositing samples, and sending about 1/2 kilo to a testing lab.

1. Collect Soil Samples

2. Reason for Soil Sampling
Soil sampling is important as it measures the
nutrients that are left in your field. Tells you which
nutrients are lacking or are in excess throughout the
soil in a field. Helps you determine the most favorable
fertilizer plan to increase or maintain yields for the
following year.

4. How to collect and package soil sample for
testing
Random
With a simple random system each soil core
is selected separately, randomly and
independently of previously drawn units. A
stratified random sample is taken from a
field that has been divided into several
subunits or quadrants from which simple
random cores are obtained. This increases
the precision for the field.

5. Grid sampling
Area is divided into sections. This
gives a better picture of the area’s
variability and density of
nutrients. It avoids the peril of
random sampling, which can lead
to too many samples being
collected from the same region.

6. Soil series
This sampling strategy uses multiple soil series – a
series being made up of multiple single soil samples.
Multiple soil series are taken and composited to create
a basic profile of each area. The two are then
compared to learn which nutrients occur in which
areas, to what degree microorganisms inhabit the
differing areas and where soil toxicity begins and
ends.

7. Topographic Unit
Natural features differ from one
area to the next. Because factors
such as slopes, elevation and
depressions differ in soil
composition, these can be used
to predict the types of soil that
will be found in a given area.

8. When to collect samples
Collect and submit samples three to six months
before a projected planting date if you want to be
able to base fertilizer plans on a current soil test
report.
In most cases, it is not necessary to take samples
every year.

9. Steps on proper soil sampling
1. Make a map of the farm showing sampling areas. Divide the farm into
sampling areas. Each sampling area should be more or less uniform in
cropping history, past lime and fertilizer treatments.
2. Collect spot soil samples from each sampling area. In each sampling area,
dig 5 – 10 pits and collect sample in each pit.
3. Take composite soil sample. After collecting all the spot soil samples of a
particular sampling area, pulverize and mix thoroughly and remove stones
and fresh leaves from the soil in the container.
Place the composite soil sample about ½ kilo in a clean plastic bag. This can be
sent to a soil testing laboratory with pertinent label and information.

10. Thank
You!