OF Dec Jan 2020

All crops and pastures need adequate boron for maximum nitrogen response
(photo by Linda Kinsey.)
Continued from Page 10
plants. Also, if phosphate is deficient
in the soil, boron will not fill the seed
or grain to the same extent as would
normally be the case.
Though some in plant genetics may
disagree, once all the other needed
nutrient levels are completely met for
producing a desired corn yield, if boron
is not kept above 0.80 ppm, the kernels
will not fill out all the way to the tip
of the cob. It is not plant genetics that
cause this problem. In every case, once
the nutrients that are lacking have been
supplied, even the most “susceptible”
varieties fill out completely. How many
bushels of corn grain are lost due to
that lack, even at ¼-inch of grain loss
per cob per acre?
As an all-too-common example, one
corn farmer, new to the program, always
had problems getting his corn to
fill all the way to the tip of the cob. This
farmer had low phosphate and deficient
boron levels in his fields. We recommended
both the needed phosphate
and the boron. However, the farmer
was convinced by his fertilizer dealer
that his soils had adequate P levels and
only needed a little starter P. This was
also advocated to farmers in the area by
the land grant university in the state.
Though sufficient boron was supplied,
the kernels at the tips of the cobs
still did not fill out completely to the
end because the soil lacked sufficient
phosphate. When both are deficient, a
primary element such as phosphate or
potassium should be given the highest
priority over any trace element, including
boron.
That same farm still uses our program.
Once the needed P was supplied and
the boron level continued to be maintained,
the cobs began filling plump
kernels of grain completely to the tip
of each ear, and the yield increase from
that extra grain is now an annual 30 to
40 more bushels of corn per acre.
Nutrient Balance
Soils need boron to maximize the size
of fruit and seed crops. But this will
not happen without adequate calcium.
Calcium is necessary to get starch into
crop leaves. Boron is needed to get the
starch from the leaves to the fruit or
the grain. If either is lacking, seed and
fruit size will also be lacking.
Consider again: this response will not
happen without the proper minimum
amount of calcium in the soil. And just
having a “good soil pH” does not assure
that calcium is adequate enough for the
best crop response to boron. It is the
soil saturation of calcium that determines
how boron will help plants to
respond in any soil. When the available
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12 Organic Farmer December/January 2020