AGRONOMY
PRECISION AG
Reading
the dirt
Soil sampling sheds light on problem areas in fields
i
By Zach Eder
dentifying investments that are most
likely to succeed is one of the most
important aspects of a successful
business. The same goes for your farm.
A strong soil sampling program is vital
to proper application of fertilizer and soil
amendments. Soil sampling can be conducted in many ways. Most commonly, a random sample, zoned sample or grid sample
is used. All methods are better than not
sampling, but more intensive sampling can
aid in identifying problems within a field.
At United Ag, we utilize a 2.5-acre grid
sample for intense sampling. This is recommended for fields that are losing production, have not been thoroughly sampled recently or are new to the producer. However,
following seasons can be sampled based on
yield maps that illustrate high and low producing areas of the field. Pulling sampling
from these areas helps determine nutrient
usage and determine causes of lost production. Grid sampling establishes a baseline
that helps identify the differences between
similar producing regions of the field.
Zone-based sampling allows similar producing ground to be treated together, and
is most successful when paired with a yield
monitor. This reduces the labor and costs
associated with more intensive sampling
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methods. This is a very strong approach to
soil sampling, and maximizes the data collected in the yield monitor.
Random sampling is the oldest method
of sampling utilized here at the coop. Each
field should have samples pulled prior to
fertility and crop decisions for the following
season. This will help identify basic budgeting for fertilizer and other soil amendments
needs. Major issues detected from random
sampling should be further investigated
to fully understand the situation us-
ing a zone or grid sample.
All sampling should include multiple
samples pulled from each target area, and
then blended into one sub-sample that will
be sent to a laboratory. This will aid is minimizing outliers in results, and helps make
more accurate recommendations. Samples
should be taken between 6 and 12 inches
deep and uniformly across all samples. All
samples taken by your coop agronomists are
GPS marked for recordkeeping.
Common findings in the Coastal
Bend region
include acidic
pH, salt
buildup
and