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RELAY INTERCROP |
Experimental Testing of Relay Intercrop, Nitrate Harvesting |
Summary
No fertilizer application was required to harvest 65 bushel per acre hard red winter wheat at 12.7% protein at 61.1 lb. test weight. No commercial herbicide was applied to the winter wheat. Excellent weed control had occurred with the previous Roundup Ready crops of soybeans and hybrid seed corn. Typical winter annual grassy weeds were not present. Wheat root disease pressure is low since wheat has not been produced in rotation in the last 25 to 40 years. The open canopy design using twin rows of wheat planted in valley ridges reduced foliar diseases and allowed sunlight to reach the lower wheat leaves. However, stand establishment was poor due to inadequate seeding machinery. Ridge design will be improved to maximize the snow trap effect allowing winter protection for higher yielding winter wheat varieties and possibly winter barley. Only 6 inches of water was used to supplement the natural rainfall. Center pivots are required to start the winter wheat timely and supply summer moisture to the soybeans. Net returns to the producer and the landlord for the harvested winter wheat crop was $150 per acre. Soybean yields are typical at 50 bushels per acre. 40 bushels per acre is considered acceptable. Soil nitrate was removed by the growing winter wheat crop which had estimated root depths of 9 to 10 feet. 186 lbs. per acre of soil nitrate N was harvested by the crop. The top six feet of the soil profile stored 100 lbs. per acre of nitrate nitrogen. The soil P has been tested at 30 to 45 ppm. Leaching of soil nitrate into the aquifer was reduced. Water quality is improved with this new system. The growing winter wheat crop pulled CO2 from the atmosphere and stored up to 2 times the atmospheric carbon over a normal 2 year rotation of corn and soybeans. Soil life was improved by observing earthworm populations. Several improvements are planned in 2003 to boost yields to the 100 bushel per acre level. The improvements will increase net dollar returns. The improvements will harvest more nitrate and sequester more carbon. Supplemental fertility may be required which will raise risk at 100 bushels per acre production level 2. Cultural management techniques will be developed for Nebraska conditions. New winter crops can now be introduced. Correct seeding and fertilizing machinery is being developed to lower risk for seeding in ridges. Custom fertilizing and seeding equipment is anticipated to accelerate the adoption allowing center pivot seed corn producers to access the technology. Licensed commercial applicators and agronomists will be utilized to transfer the technology. Grain bins should be the only major new investment for the producer.
Center pivot seed
corn producers harvest hybrid seed corn in early September in
Nebraska. Seed corn is normally harvested on the cob with pickers and
special wagons so an early harvest is the norm. Seed corn is
produced with commercial fertilizer and no shortage of nitrogen is
required to produce top quality seed. Soil phosphate levels are
sometimes elevated to 30 to 45 PPM. The soils are 2 to 3% organic matter
at 6.5 to 6.8 Ph. This assures the highest quality nutrient
packed seed for the hybrid seed companies. Seed corn must be
picked timely in September even in wet conditions. A
killing frost can come early and damage the hybrid seed. The seed corn
is specially dried by the seed corn company to a critical
moisture value to assure a high level of germination.
Hybrid seed corn is somewhat similar to
how foundation and certified
winter wheat seed is produced in the PNW using a high level of
residual nutrients from a potato ground rotation to propagate
certified winter wheat seed. High quality seed is produced using
nutrient rich soils.
Nutrient packing of the seed kernel produces additional plant vigor from a large heavy kernel for winter wheat stand establishment (8,500 seeds per pound). Potato ground also tends to have less potential for wheat root diseases. The potato ground is also located in an area west of the Cascades that has very little potential for head scab (snow mold life cycle). The prevailing winds of the Pacific Push from the Gulf of Alaska and the dry rain shadow Columbia basin climate allows for ideal winter wheat seed production.
An environmental
problem sometimes occurs with corn and seed corn production.
Nitrate can be leached below the root zone of the irrigated seed corn
due to a mismanaged watering schedule. Continuous corn rotations and up
7 pounds of N per inch of irrigation water adds to the problem.
Irrigated corn root systems have about 1/2 the depth of dryland corn.
The normal rooting depth of irrigated corn is 3 feet. Dryland corn
is no deeper than 6 feet. Spring and Summer storms can also make water
and nitrogen management difficult at best for corn production.
See graphs A and B regarding corn root
systems for irrigated and dryland.
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Seed corn is produced in the typical Midwest short rotation following soybeans. Ridge till/No-till systems are normally used in Nebraska. These advanced No-till systems or farming allow non mobile nutrients P and K to be stored and in perfect alignment for roots of the following crops. If tillage is implemented the bands of placed P and K become positionally and chemically unavailable to the following winter wheat crop.
Most agriculturist agree that the
rotation of corn and soybeans is a dangerously short rotation. A longer
rotation is needed to reduce risk and take advantage of the synergism of
a longer rotation using less chemicals. Longer rotations also produce
less market risk and allow more marketing opportunities. In fact
livestock is often used to strengthen the cash flow and improve
liquidity. This is one of the purposes of using longer rotations.
Longer rotations improve the soil life
(microflora). Earthworm populations increase in longer rotations.
Earthworm populations are often studied to confirm the status of the
living soil.
Longer rotations using cool season
soil cover crops limit soil wind erosion with No-Till techniques.
This became clearly evident on May 22, 02 when two Interstate 80 vehicles
collided in blowing dust killing two people near Seward, NE. The jet stream dropped down to the deck
in a northwestern air stream flow. The dry warm 80 F winds were clocked at
80 mph. The wind erosion event blew directly into the path of the drivers
line of sight. The exposed and tilled fields
adjoining the Interstate lost 20 to 50 tons per acre of valuable top soil.
A cover crop of winter wheat in a relay intercrop would have protected the
soil and saved irreplaceable family members.
PHOTO TAKEN JUNE 4 / 02 AT PAUL GANGWISH INTERCROP FIELD, GRAND ISLAND, NE
The soybeans produce
about 1 pound of nitrate nitrogen for each 1 bushel of production.
Maximum soybean yields are in the 60 bushel per acre range so 60 pounds
of organic nitrate nitrogen are produced by the soybean legume.
Corn requires
1.1 pounds of nitrogen for each bushel produced. Seed corn does not
yield as high as field corn since 2 out of 12 rows are used for
the male parent and the hybrid plant vigor is not available from the
inbreed lines producing the new hybrid seed variety. So yields of
70 Bu. per acre to 140 Bu. per acre would be considered normal for
irrigated hybrid seed corn production. Thus the seed corn companies
reward the producers with financial incentives to produce top yields and
to compete with standard corn
production economics.
Soil sampling
following seed corn harvest indicates 100 pounds of mobile nitrate
nitrogen is stored in the 6 foot profile following seed corn harvest.
The soil nitrate levels for irrigated corn are normally sampled to 3
feet. ARS scientists have carried out research in the 3rd to 6th foot
determining where the nitrate is being stored. It is also known that
nitrate has accumulated below 6 feet and moving towards the shallow
water table. The key is to remove the mobile soil nitrate and all the
root profile soil moisture with the growing crops. This lessens the
chances of more nitrate moving below the root zone.
Estimates have been made that the US
has $21 Billion of nitrate (based on 21 cent N) that has moved below the
corn root system profile. Commercial nitrogen fertilizers were
introduced to Midwest agriculture 50 years ago. It is becoming a
most critical period in agriculture to reduce this uncontrolled emission
of nitrate into the drinking water.
Seward, NE on July 18, 2002 in fact issued orders to city water customers to not drink the water from city wells. The drinking water nitrate levels were above 10 PPM. Only 1 PPM is permissible in Europe. Seward, NE is an irrigated corn production area about 40 miles west of Lincoln and just north of I-80 along the Big Blue River. The Big Blue River drains into the Kansas River at Manhattan, KS. The source of drinking water nitrate is most likely from irrigated corn production from the last 50 years.
Nebraska is favored
for seed corn production due to the
ability to manage water and nutrients better than other areas of the
corn belt. Also the transportation to the eastern corn belt and the
western United States is excellent. The western corn belt tends to be
more consistent supplier of the hybrid seed corn production. This is
because the harvest is normally drier and the water cost is less.
The Nebraska seed
corn producers have a very unique advantage in a new system of farming
that is being led by USDA-ARS scientist Jim Schepers of Lincoln, NE,
seed corn producer Paul Gangwish of Grand Island, NE
and assisted by Guy Swanson of Spokane,
Washington. Swanson is providing agronomic and machinery technology
support. The transfer of this new crop production technology is coming
to Nebraska producers from private and government sectors.
Center Pivot Irrigation Is Required.
PHOTO TAKEN JULY 20 / 02 AT PAUL GANGWISH INTERCROP
FIELD, GRAND ISLAND, NE. WINTER WHEAT HARVEST OCCURRED 14 DAYS
EARLIER
Nebraska was
originally a winter wheat
state so the climate favors wheat. However winter wheat is
seldom raised under center pivots in Nebraska. Most winter wheat acres
of Nebraska are found in the much higher, moderate dryland rainfall,
3,000 feet to 5,000 feet elevation, of the western panhandle. A small
acreage of dryland winter wheat is raised south of the Platte River
Valley towards the Kansas state line.
The early seed corn harvest permits
high yield stand establishment of winter wheat
under center pivots at much lower
elevations. The center pivots located in the Platte River
valley combined with good water management tends to favor a cool season
crop such as winter wheat. This valuable tool allows an excellent fall
start of winter wheat at elevations of 1,900 feet and 41 degrees
north. Average mean low temperatures at Grand Island, NE are 12 degrees
F in the coldest month, January.
PHOTO TAKEN JULY 15 / 02 AT PAUL GANGWISH INTERCROP FIELD, GRAND ISLAND, NE. WINTER WHEAT HARVEST OCCURRED 5 DAYS EARLIER
The "Flywheel Effect"
of soil irrigation is utilized. Center pivot production of winter wheat
also has another advantage over dryland wheat. The soil takes longer to
freeze in the fall and stores this heat longer going into the winter
months. The center pivot soils have stored moisture. More energy from
the environment is required to drop the soil temperature. Thus more
energy is required to warm the soil in the spring. The break in
dormancy is delayed. The winter wheat will grow longer in the fall
allowing the wheat to develop deeper root systems. You can measure this
"Flywheel Effect" by observing the time it takes water to boil in
microwave. A half full glass of water will boil faster than a full
glass of water.
Jim Schepers has taken a whole
new approach in seed corn production. Why not raise two crops
in a well managed relay? His
new approach is used to manage
nitrate leaching and absorb carbon from the atmosphere by raising two
crops per year following seed corn. He has observed Relay Intercrop in
Argentina and came back with some fresh ideas for Nebraska seed corn
producers using center pivots. Producer Paul Gangwish likes the new
system since the economics are quite favorable and it just matches his
workload.
Farming is a
Controversy with Weeds
The reason Jim Schepers approach has a high degree
of success is simple....Weed Control, low wheat root disease pressure,
leverage fertility, Ridge Till and a dedicated area for Roundup ready
soybean establishment. Previous attempts to Relay Intercrop in Nebraska
have been tried. In fact in 1989 UNL researchers carried out studies
and published a NebGuide for Relay Intercropping titled, Two Crops
in One Year: Relay Intercropping.
www.unl.edu/pubs/fieldcrops/g1024.htm.
Irrigated Platte Valley Nebraska wheat
has not been raised since the 1960's when center pivots were developed.
After all Nebraska is the Corn Husker state. Therefore wheat root
diseases and typical winter annual weeds such as Jointed Goat Grass,
Ripgut Brome and Downey Brome are hard to find. The most difficult
weeds in winter wheat production are winter annual grasses, fall and
spring Wild Oats and Russian Thistle. The most difficult perennial
noxious weeds are Morning Glory and Canadian Thistle. In the PNW these
weeds dictate long four year rotations with three spring crops or a two
year rotation with weed control cost of $25 to $30 per acre. Wheat is
not a GMO crop so weed control costs are quite high for each bushel of
wheat produced.
If GMO wheat is released the acres
dedicated to wheat will increase substantially. Low rainfall areas will
immediately drop summerfallow winter wheat type systems and proceed
immediately to No-till annual cropping of spring wheat in certain areas
of the country. GMO winter wheat may not be released because USDA-ARS
scientists are very close to offering perennial winter wheat. Perennial
winter wheat is the most moisture efficient crop for the high desert of
the western US. The National Corn Growers Association has voted against
GMO wheat since an oversupply of a cheaper cattle feed source could
drive down corn prices. GMO spring wheat is about two years from
release. It has been tested since 1995 under APHIS.
Never forget, "The number one reason
farmers farm the way they do is because of the weeds".
When Roundup Ready crops became
available in the mid-90's the field could be maintained and groomed with
Roundup rather than more expensive residual selective herbicides. It is
critical to maintain a strong weed control program in the seed corn
rotation for the winter wheat to be established correctly. No residual
herbicides can be present in the winter wheat soil seedbed since
residual herbicides hurt the winter survival of winter wheat. In fact
it has been observed that no selective herbicide application is required
in
this new winter wheat system if the proper weed control occurs in the
soybean and seed corn crop.
Another reason why weed control is so
superior in this new system is the applied commercial fertilizer comes
only from the No-till/Ridge-Till seed corn production. The fertilizer
bands are no-till applied and always in ideal alignment with the seed
rows. The winter wheat plant traps the fertilizer and prevents weeds
from accessing the residual bands of placed fertilizer. This is
especially effective to improve winter wheat roots geometric access to
placed P and K.
This is a new method of raising winter
wheat in a strong and thrifty group of winter wheat seed rows. The seed
rows are directly over the residual placed fertilizer bands of NPK. This
method favors the winter wheat crop and hides the fertilizer from the
weeds. This time proven approach of Paired Row was introduced by
Yielder Drill in 1982. Paired Rows of winter wheat geometrically and
postionally aligned with deep bands of fertilizer are more effective in
raising winter wheat. This information is found in a published article,
"Feed the Wheat and Starve the Weeds" as reported by Glen Lorang of the
Farm Journal.
Weed control in the early harvested
seed corn is excellent. The male rows are normally mowed down after
tassel. Thus weeds can regenerate in 2 out of 12 rows. These weeds
must be controlled right up to harvest date. It is important to control
the weeds since a "Green Link" can occur. The "Green Link" is a bridge
or means of transfer for insects that harbor in the growing and
succulent green weed mass. The insects such as wheat mites, and aphids
begin to feed on the new winter wheat crop and implement wheat diseases
such as Leaf Streak Mosaic and BYDV.
If Roundup is applied immediately after
harvest to large weeds the die down of the large weeds will provide an
ideal environment for Rhizoctonia Bare Patch. Rhizoctonia will
proliferate from the decaying weed mass to the emerging winter wheat.
Rhizoctonia mycelium reach out about 8 inches from the decaying mass and
attach to the emerging wheat. It is highly important to control weeds
in the growing seed corn crop. The recommended practice for seeding
wheat is to wait three weeks after applying Roundup to large weeds to
avoid the Rhizoc problem. This is not a unique phenomena of the PNW
since Rhizoctonia has been observed throughout the corn belt.
Wheat in the
Rotation
Planted wheat acres of all classes have
continued to decline from 80 million acres in the mid 1980's to
60
million acres this year. CRP reductions of wheat land and the
technology or Roundup Ready Corn and Soybeans has allowed No-till
farming to be expanded on previous old fashioned summerfallow
winter wheat acres.
The farm program also tends to favor populated areas of the Midwest
which raise corn and soybeans. Wheat is considered a desert crop for
low population areas of west of the 100th meridian (Grand Island, NE).
Harvested winter wheat acres show the
biggest decline with only 30 million acres to be harvested this
year. Hard Red Winter Wheat is estimated at 20.7 million acres. The 30
million acres of harvested winter wheat is the smallest total acreage since 1917.
Hard Red Winter Wheat acreage abandonment is the second highest since
1950 in the Hard Red Winter Wheat Belt (Texas to South Dakota). This
year 28% of the Hard Red Winter Wheat crop was abandoned due to very
dry conditions.
World supply of wheat continues to
increase about 2.3% this year. Annual export market for US wheat was up
about 8% as of early May, 2002. This may be due to the falling dollar.
Wheat is a good rotation crop. Winter
wheat sequesters CO2 from the atmosphere. Winter wheat improves soil
tilth by storing carbon longer than such crops as soybeans and corn.
Wheat residues normally take longer to break down and release nutrients
including CO2. No agronomic or environmental disadvantages are known
when raising winter wheat in rotation with corn and soybeans.
Winter wheat is not a GMO crop. This
may be a major advantage to the seed corn producer since weed control is
so superior in the GMO beans and corn. No selective or residual
herbicide is required to raise the winter wheat in this rotation. Any
application of a selective herbicide will damage wheat to some degree.
This new system of farming uses less herbicide and harvests nitrate
which does reduce commercial fertilizer nitrogen use. CO2 recovery from
the atmosphere could double with this new system.
This new system of raising two crops in
one year has very unique advantage over typical winter wheat budget
scenarios. Winter wheat in the high rainfall PNW dryland production
area requires at least $35.00 per acre for commercial fertilizer.
Additional budget requirements for weed control and soil disease
fungicides increases costs another $30 to $45 per acre.
A Great Fall
Start
Winter wheat tillers twice, once in the
fall and again in the spring. Winter wheat will develop a deep root
system and harvest nitrate if the crop is established in best of
condition going into the winter. In fact winter wheat has the maximum
winter hardiness when only phosphate type fertilizer is used to harden
the plant. Phosphate causes the cell walls to thicken. Nitrogen causes
the cell wall to elongate and weaken. Nitrogen application is not
recommend for maximum winter survival This is one reason why winter
wheat can now be raised in Canada. Nitrogen is applied in the spring
rather than the fall.
Winter wheat should be seeded as
shallow as possible under center pivot production. The seed should be
placed at 1/2" and no deeper than 1". This allows quick emergence and a
more extensive root system going into the winter. Winter wheat can be
seeded too early. Optimum seeding dates vary based on elevation,
daytime soil temperatures, and insects.
Seed corn producers in Nebraska have
very special advantages in producing top yielding winter wheat crops in
an intercrop relay. Center pivots provide a great fall start of winter
wheat which adds to the winter wheat yield and winter survival of the
crop.
Ridge Till Favors Winter Wheat |
The ridge effect must be maintained to
enhance winter survival in heavy corn residue. Better winter protection
means higher yields.
Insecticide capability is required for
the early fall start. Insecticide can be deleted after freezing nights
but some yield compromise can be expected due to later seedings.
The lowest possible winter wheat seed
rate will be utilized to promote fall tillering using high quality
certified wheat seed ($12 per bushel, certified, $18
per bushel, Hybrid). The seed metering system must
have a CV of 5% or less using an air delivery type system similar to Valmar or Gandy. Typical airseeder metering systems used in low yield
wheat production of the northern great plains and Canada are not
acceptable for high yield irrigated winter wheat production. Seed cost
must be reduced and stand establishment is too critical for the high CV
airseeders.
The opener and depth control is
critical in ridge till. Large diameter single disc openers that can
place two seed rows and deep band MAP, MAPS, and AS simultaneously have
been selected. The seed bed must be firmed. The seed depth control
must be maintained within 1/2" to 1" in heavy corn stubble residue.
The combine is
equipped with a dual tire spacing that allows the wheat to be harvested
with no damage to the emerging juvenile soybeans other than the field
lands. The combine must be equipped
with a chaff spreader capable of spreading wheat chaff 30 feet. The
chaff spreader is critical to control volunteer wheat in the soybeans.
The grain buggy (bankout wagon) and the
tractor hauling the grain away from the combine also matches the gauge
width required for the ridge till spacing of 30 inches. This spacing
matches the combines tires previous pass. So straight, on the mark
driving, of the bankout wagon is required to the field lands. This is
not unusual for Ridge Till producers. As yields approach 100 bushel per
acre the bankout wagon must be timed to the combine bulk tank capacity.
On the go bulk tank unloading is required. Excellent driver skills are
required to maintain controlled compaction and to
avoid soybean damage.
Adjustable
gauge width, narrow belted tractors (14" belts and narrow midwheels) are very
compatible with this new system. A Deere belted tractor was utilized in
the initial center pivot test. However, a wheel tractor would also
work. 12.4 x 54 Michelin tall tires and rims are available on a 90"
gauge width. Producer Steve Wiese of Claytonia, NE,
www.exactrix.com/kinze.htm, has
modified his Deere 7710, 135 horsepower tractor to the tall 12" narrow
tires for 120" gauge width sprayer operation using a 90 foot boom. The
tires have a 9600 pound load rating
Caterpillar
has announced the MT series tractors rated up to 285 horsepower with 14"
wide belts and narrow midwheels. The unique aspect of the Cat MT
tractor is the adjustable gauge width to 150" or even greater out to
165" if required (Hillside). Wide gauge width
is extremely desirable. Power delivered to ground in turning
and stability of the seeding platform is enhanced. The Cat MT has a
three point rating of 16,000 lbs. with a 55 gpm pressure compensated
hydraulic system.
If you have interest in wide gauge width tractors
you can review this subject at
http://www.exactrix.com/LargestApp.htm.
You can also contact your Caterpillar dealer
regarding the new MT series tractors. Wide gauge width is time proven,
very desirable.
If custom seeding drills and
applicators become available the only additional new major investment
should be grain bins to store and handle the various categories of high
quality milling wheat. This should not be a difficult hurdle for
Nebraska producers. Home storage of wheat has been proven to be good
government subsidized program over the last 20 years.
A Mortgage
Lifter.
Nebraska seed corn growers have a
unique scenario that comes by once in a lifetime for a producer. Why?
1. Two crops in one year. 2. Better use of the land. 3. Meet and
exceeds environmental requirements. 4. Minimum machinery investment.
5. Less financial pressure by rolling the dice three times in one year.
Land values should increase in this new
system. The paydown of debt should accelerate.
If you further questions about the progress of
this new system please e-mail Guy Swanson at
www.exactrix.com.
This htm will be updated following the soybean harvest.
Perennial crops such as alfalfa and clover have a taproot which is larger in diameter and usually have deeper rooting systems than corn. (From Jean and Weaver, 1924) Perennial and winter annual crops such as winter wheat and triticale have deep root systems that can harvest nitrate, carbon sequester and reach rooting depths of 10 feet. |
Exactrix®
Global Systems LLC 4501 East Trent Ave. Spokane, WA 99212 www.exactrix®.com 509 995 1879 cell, Pacific. exactrix@exactrix.com |