Better Farming February 2017

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CROPS: YIELDMATTER$
Soil organic matter content and
soil health are closely linked
when it comes to defining
healthy soil. Many farmers and
industry representatives struggle with
defining soil health in a single word
or sound bite to convey its impor-
tance for sustainable crop production.
What we all agree upon is that soil
has three basic components that
work together: physical, chemical
and biological. Soil organic matter
has a positive impact on all three
areas. The graphic below developed
by the OMAFRA Soil Health Work-
group puts it all in perspective. The
three components overlap each
other. In the centre, where all three
components intersect, we see the role
of soil organic matter (SOM) in
connecting all components together
into one system. This system conveys
the various aspects of soil health and
how they work together to support
the sustainability of soil, our most
important asset.
Understanding soil organic matter
Determining SOM content in any of
your fields requires a soil test.
Submitting a representative soil
sample to an accredited lab and
requesting a SOM test will provide
you with a result expressed as a
percentage.
A typical loamy soil in a corn-soy-
bean-wheat rotation may have a
SOM level of 3.0 to 5.0 per cent.
Most lab analysis methods actually
measure organic carbon and convert
Managing soil organic matter content
When planning crop rotations, it is important to consider the specific crop’s impact on soil organic
matter (SOM). Other tools, such as cover crops, manure and compost also impact SOM.
by DALE COWAN