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Fertilizer costs nearly double what they were
in 2006
Skyrocketing fertilizer prices and the current drought make it
important for wheat producers to gauge nitrogen needs accurately
this year. The N.C. Department of Agriculture and Consumer Services
is advising growers to base upcoming fertilizer decisions on tiller
counts and plant tissue analysis results.
"Last fall, nitrogen was selling for $180 per ton. This year
the price is up to $320," said Ben Knox, a regional agronomist
with the department. "No one wants to apply more than is
necessary, especially when it is likely that some fields still
contain residual nitrogen from the previous crop. This year growers
really need to get into the field and scout early and often."
The time to count tillers is in late January or early February
when wheat begins to green up. At this stage, 50 to 70 tillers
per square foot is optimum. If wheat was planted late, tiller
counts may be significantly lower. In that case, it is appropriate
to apply 30 to 40 pounds of nitrogen per acre right away. This
application will enhance tillering on warm days without fostering
excessive growth.
Tissue testing should be on the calendar in late February or early
March. Precise timing will depend on weather and crop growth stage.
Tissue sampling to evaluate nitrogen levels in wheat should coincide
with Zadoks Growth Stage 30, also known as Feekes Stage 4-5. At
this stage, wheat is usually 5 to 6 inches tall, stems are upright,
and tillering has stopped. To determine whether wheat has reached
this growth stage, dig up a plant, slice it down the middle and
measure the distance from the bottom of the plant to the top of
the growing point. If the measurement is one-half inch, it is
time to sample.
Because of the ongoing drought, tissue testing is a must this
year. Plants need water to use nitrogen, and the lack of rain
means it is likely that nitrogen from the previous crop is still
in the soil. If wheat is thriving on residual nitrogen, tissue
test results will point that out and you will be able to adjust
spring application rates accordingly.
Brenda Cleveland, chief of the NCDA&CS Plant, Waste and Solution
Section, said tissue testing is crucial to appropriate nitrogen
fertilization, but it often uncovers other nutrient problems,
too.
"Wheat producers are most concerned about nitrogen,"
Cleveland said. "If they apply too little, there will be
fewer heads and fewer and smaller kernels. If they put out too
much, there may be problems with lodging, disease, leaching or
runoff. At least half of our tissue tests, however, reveal that
potassium, magnesium or sulfur levels are also low enough to limit
yield. With wheat prices remaining favorable this year, growers
have extra incentive to follow all plant report recommendations
carefully."
To collect tissue samples, break plants off about one-half inch
above the ground. A good sample consists of about two handfuls
of plants gathered from 20 to 30 areas throughout the field.
In early 2008, the NCDA&CS Agronomic Division will hold training
sessions in the eastern part of the state on how to count tillers,
identify wheat growth stages and collect tissue samples. For training
dates and locations, contact regional agronomist Wayne Nixon at
(252) 335-4142 or Kent Yarborough at (252) 793-4118, ext. 122. |
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