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Fall 2002
Northcentral
Variability in crop health throughout the Northcentral region has been dramatic
this season. Some areas have been subjected to overwhelming drought and heat
while others have seen good conditions. All of this means that this fall it
will be important to look back and see what yields were planned at the beginning
and what yields actually were harvested. How much phosphorus (P) and potassium
(K) did crops remove this year? How much have they removed during the past
few years? Sustained low crop prices have led many to skimp on their P and
K applications for several seasons. It is time to look back and see if nutrient
applications have been keeping up with the nutrient removal by crops, or if
they have been falling behind…not just this year, but for the past several
years. Mining soil supplies requires a watchful eye to ensure soil test levels
do not fall to yield-limiting levels. Decisions to apply P or K must be based
on more than this season's crop performance. Looking farther than just one
season puts this year's crop performance in perspective and helps better evaluate
fertilization decisions.
For information on how much P and K is
removed by various crops, visit the Crop
Nutrient Utilization Chart on the Back-to-Basics homepage.
Northeast
The cool and wet weather of May is long forgotten in many parts of the region.
Recent rains have alleviated drought pressure on corn and soybeans in much of
the region, but drought remains a very significant factor in areas missed by
the rains, especially because of high temperatures experienced in July and continuing
into August.
Autumn approaches. Soon forage plants will
enter the critical fall growth period, during which they store
the carbohydrates they need to survive the winter. Adequate potassium
(K) is essential for this carbohydrate storage, and August is
an excellent time to apply fertilizers as needed. Potassium is
particularly likely to run short if previous harvests have been
heavy. The amount to apply is an important decision. Make sure
it's based on a recent soil test, and supported by forage analysis
as well. Calculating a nutrient balance - nutrients removed by
previous harvests minus the amounts supplied in manures and fertilizers
- can also help determine the right amount to replace. For harvested
cereals underseeded to forage, K should have been supplied at
planting. But if it wasn't, applying as soon as possible after
cereal harvest will ensure the seedlings develop into winter-hardy
plants.
Winter wheat has performed well in many
parts of the region, with good yields and very little mold and
mycotoxin. For next year, assure yourself a good start by planning
for the fertility needs of the crop to be seeded this fall. Nitrogen
(N) and phosphorus (P) are important components of a starter
to ensure a healthy stand. Wheat can be profitable, as well as
an excellent soil builder in the rotation.
Manure applications following harvests
of cereals and silage corn should be guided by soil tests and
manure nutrient analysis. Rates should be appropriate to supply
the soil's needs for P, K and organic matter. Avoid wasting N
by ensuring a cover crop grows to absorb what is released from
the manure.
Northern Great Plains
Soil testing is the best means of establishing a soil's phosphorus (P) supply
capability. Unlike nitrogen (N) and sulfur (S), where residual levels are recorded
with a soil test, P soil analysis provides an index of the soil's ability to
supply a growing crop. A low soil test level for P indicates a high probability
of improving crop development and yield with nutrient addition. A soil with a
high P soil test is said to be well buffered. That is, it has the ability to
maintain soil P levels at a high level even with crop removal. In the absence
of nutrient addition, this P supply rate from the soil will decline over time
and be reflected in lower soil test levels.
When sampling for P and potassium
(K), you need to have a good understanding of the
field history. A clear understanding of where not
to collect soil cores for a composite sample in a
field can be as important as selecting representative
locations. Old farmyard sites, pastures, or manured
portions of fields can all lead to a high soil test
reading which may in fact not be representative of
the majority of the field. This requires that the
farmer travel with the soil sampling truck to help
the operator steer clear of these potentially problem
areas. All the technology in the lab cannot compensate
for a sample collected from an inappropriate location.
Given the important role soil
testing plays in nutrient management planning, collection
of a representative sample is critical. This means
ensuring that the landowner clearly describes the
representative areas of each field to be sampled,
and identifies where manure was applied and how fertilizer
P and K have been placed in the past. Remember, representative
soil tests can help take the 'guess work' out of
crop nutrient management.
Great Plains
Drought conditions stubbornly persist over parts of the Great Plains region.
For example, much of eastern Colorado and western Kansas remain under brutally
dry conditions. Substantial acres of the last winter wheat crop were not harvested,
and many acres of this year's dryland corn crop will be abandoned due to lack
of grain production. As growers plan for the next crop in these fields, nutrient
carry over should be considered. Where no grain or forage was removed from fields
due to crop failure, residual levels of both N and P will likely be higher than
in an average production year. In contrast, yield potential in other regions
is excellent. For example, the yield potential of south plains cotton is excellent
this year. As is typical for the region, growing conditions and crop production
potential are highly variable.
Planning for cool season forage
establishment and production is well underway. Growers
and ag professionals should remember that fertility
is an input that significantly affects not only yield,
but also forage quality. Profitability from a forage
production system is largely determined by the amount
of animal product (beef, milk, wool, etc.) generated
in that system. The amount of product generated in
a forage system is a function of the number of animals
carried per acre (stocking rate), and the production
per individual animal. Forage quantity (yield) is
the primary determinate of the number of animals
an acre will bear, while forage quality is a major
determinate of product generated per animal. Therefore,
within a forage production system, yield and quality
combine to determine how much animal product will
be generated per acre… the ultimate measure
of success. Following this logic and using these
facts, it becomes clear that in cool or warm season
forage production systems complete and balanced fertility
is critical to generating optimal levels of the desired
animal product and to maximizing profits.
Midwest
For most of the eastern Midwest, 2002 is a growing season that farmers and dealers
would like to forget. May was wet, followed by extreme hot, dry weather for June
through early August. The August USDA crop reports reflected the situation with
substantially lower yield predictions for most of the eastern Corn Belt. Kentucky
is the only state in the PPI Midwest Region with a positive crop report.
What does this mean for 2003?
That is the question we need to think about. Where
soil tests were marginal in 2002, drought stress
had more severe effect on crop yields. Potassium
(K) is essential to water use efficiency. This is
not a new idea, but it was brought home in fields
across the region this summer. The 2001 PPI Summary
of Soil Tests in North America showed a growing need
for K. The 2002 season reflected it in reduced yields
and profits for producers who have been too conservative
in their nutrient applications. That condition will
not go away; it must be fixed with improved K applications.
We will continue working with dealers and farmers
this winter to help them assess how much they are
losing with low testing fields or areas within fields.
It is a major economic problem that is easily corrected
with proper K management.
Southeast
Persistent drought conditions in North Carolina, South Carolina, and Georgia
will hurt crop yields this year.
Peanuts in Alabama, Georgia,
and Florida are maturing. In spite of some recent
showers in localized areas, drought earlier made
prospects for a fair to good crop unlikely. More
recent widespread rain in the Southeast has improved
the yield potential, but increased farmers' expenses
as they apply fungicides and insecticides to protect
the crop.
Recent rains in portions of
the region have helped soybean crop development.
Early-maturity fields are nearing harvest. Insecticides
are being applied to control stinkbugs, but the stinkbug
numbers have declined since early July in many areas
in the middle South. Some fields with leaf and pod-feeding
worms were also being treated. Yield potential looks
pretty good in irrigated fields, and the dryland
fields that received moisture during bloom to pod-filling.
The cotton crop is maturing
and some of the April-planted fields will be terminated
soon in preparation for picking. Bolls were opening
in the southern portion of the Southeast cotton belt.
Insect pressures seem to be increasing in some areas:
bollworm, budworm, tarnished plantbugs, and spider
mites. The weather the next ten days to two weeks
will be critical for many farmers. Farmers who are
striving for high yields, with the assistance of
irrigation, must be sure that plants receive optimum
moisture over the next several weeks, to fill out
bolls, and to allow the crop termination (defoliants
and boll openers) to work effectively.
Rice harvest continues in south
Louisiana, with about 20 percent harvested to date.
Yields are fair to good, but bin-busting yields are
not expected. Fields in other parts of the southern
rice growing region are mostly headed and many are
approaching the dough stage. Fields will be drained
in the next several weeks in preparation for harvest
in Arkansas, Mississippi, and the bootheel of Missouri.
Sheath blight is a concern in some fields and farmers
and consultants are scouting and treating for sporadic
stinkbug outbreaks. Many farmers in the region will
be under a lot of pressure to harvest mature rice
fields and early-maturity soybean fields in a week
to two-week harvest window, to achieve optimum crop
quality.
Sorghum harvesting has begun
in some states, with other states reporting rapidly
maturing conditions. Yields were reported as fair.
Sweet potatoes were in mostly
fair to good condition. Tobacco harvesting is moving
along at its normal rate. Peach harvest is nearing
completion and apples are rated in good condition.
Many cattlemen are feeding
hay because of continued drought. Yet in parts of
the Southeast, farmers were rapidly baling summer
hay where moisture was more plentiful. Where moisture
was adequate, farmers were fertilizing pastures and
hay meadows.
In citrus, some fertilizer
and pest management applications had to be supplemented
because of recent showers and thunderstorms in Florida.
Sugarcane was rated as good
to excellent in Florida and Louisiana.
In several states, land was
being prepared for fall vegetable planting.
This fall would be a great
time to sample fields, especially where fertility
needs have been neglected in recent years. If lime
is needed, based on soil test results, applications
this fall would help ensure that soil acidity is
reduced and that the soil pH is in the optimum range
at planting.
Fall applications of potassium
should work just as well as spring applications,
except on the sandier soils with a low cation exchange
capacity (below 5 to 7 milliequivalents /100 grams).
Fall applications of phosphorus are also appropriate
where soil pH levels have been properly maintained.
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