Successful crop production is a combination of many elements, two of which
are absolutely essential:
 proper management of inputs
and
a thorough understanding of
the soil
resources and how
they respond to
management.
Knowledge of the soil types you have is critical for determining whether conservation tillage
can work for you. Because there are so many kinds of conservation tillage systems, you'll
likely find one that is adaptable to your soils. However, some soils can certainly provide a
greater challenge.
Even if the soil itself wouldn't impact the tillage system you choose, the soil's interaction
with factors like climate can also determine a system's ability to help you succeed.
Soil drainage
For instance, internal drainage is an important factor in deciding if your soils are adapted to
conservation tillage. Both natural and man-made drainage can make a difference. Better-drained
soils usually have a yield advantage when crops are grown in high residue systems.
Yield maps may show great variability in different areas of a field. Many factors influence
field variability and yield potential (like soil drainage, texture, organic matter, etc.).
While some factors can't be changed, many can be addressed through management. The yield map
above is overlaid on a soils map.
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No-till, in particular, performs best on well-drained soils. These include coarse-textured soil with good internal drainage (such as sandy loams), soils that provide good surface
drainage (sloping land), and soils without layers that restrict water movement within the root
zone (such as fragipans or claypans).
Tiling (or using man-made field drainage systems on)
poorly drained soils can dramatically improve crop performance. Tiling removes excess water and
allows faster drying and warming in the spring. Of course, the soil's ability to dry is also
affected by type and amount of crop residue remaining on the surface and degree and timing (fall
versus spring) of tillage used.
Soil texture and organic matter
Your ability to manage crop residues can dramatically improve soils. Conservation tillage
systems offer special advantages for farming soils with less than 2.5% organic matter or soils
high in silt. After several years of no-till, improved soil physical properties near the
surface often lead to more uniform plant stands than conventional tillage on the same soil.
As mentioned, research shows a definite link between amount of tillage performed and the soil's
ability to hold carbon. Carbon accounts for about half of a soil's organic
matter, which is critical to long-term productivity.
An Indiana study showed that no-till corn yielded higher than other systems on a soil that
contained only 1% organic matter, had poor structure, and was poorly drained. Overall, crops in
rotation had better early growth and higher yield than the same crops under conventional tillage
systems (possibly due to reduced crusting).
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