Nebraska farmers are field testing a relay intercropping system that rotates seed corn, wheat and soybean over two years to provide for soil nitrogen use and an additional crop and income source. After several years of tests, they are now modifying and adapting the system to their individual enterprises. This field is an example of two rows of wheat spaced at 10 inches, leaving 20 inches for the soybean crop. (See more on relay intercropping below.) (Photo courtesy USDA research team)

December 10, 2004

Soybean rust fungicides approved for Nebraska for 2005

Sites of confirmed soybean rust in the United States, as of Dec. 3. (View larger map)

On November 12, rust was confirmed at two locations in Louisiana, Pointe Coupee Parish and near Baton Rouge. A few days later the disease was confirmed in Iberia and St. John Parishes, Louisiana, and from a site in Adams County, Mississippi and near Quincy, Florida. On November 19 positive confirmations were announced at two locations in Georgia — Seminole and Jeff Davis counties -- and in Mobile County Alabama. On November 22, rust was confirmed in Crittenden County, Arkansas. On November 30 rust was confirmed in Pemiscot and New Madrid counties, Missouri and Allendale and Pickens counties in South Carolina. On December 1, soybean rust was confirmed near Memphis, Tennessee.

It appears that soybean rust was widely distributed by hurricane Ivan in September 2004. While this disease is not expected to overwinter north of the 30^o north latitude (north of Baton Rouge), it is predicted that summer weather patterns will move spores north from overwintering, sites much as wheat rust spreads northward in the late spring and summer.

EPA gives Section 18 approval to fungicides

Several products have received EPA approval for soybean rust under a Section 18 emergency use exemption. Those products are: myclobutanil (Laredo), propiconazole (Tilt, Propimax, and Bumber), and tebuconazole (Folicure). Additional products still pending Section 18 approval include tetraconazole (Domark) and a mixed product of propiconazole and trifloxistrobin (Stratego). In addition to these, other products may be submitted for Section 18 approval. Federal tolerances for pyraclostrobin (Headline and Pristine) have been established for soybean and as of December 3, Headline had received full label for use on soybean. Products which have soybean rust on the label and are registered in Nebraska include chlorothalonil (Bravo and Echo) and stobilurins (azoxystrobin – Quadris and pyraclostrobin - Headline).

In general, chlorothalonil and strobilurin products have not been shown to be effective in South America after rust is well established in the field. In some studies, increased residual activity has been observed with strobilurins in a tank mix application with a triazole. Therefore, when soybean rust arrives in Nebraska, I would recommend using Section 18 products in the triazole chemical group unless you are making a preventative application prior to arrival of rust. Based on South American trials, the triazole group appears to be very effective. It includes myclobutanil, propiconazole, tebuconazole, and tetraconazole. Surely, over the winter, more products will apply for and receive a Section 18 emergency use exemption.

The bottom line

We are ready for soybean rust. It will have an impact on U.S. soybean production, but its annual impact in Nebraska will vary depending on the weather. Nebraska is on the fringe of favorable climate for disease development.

Many University of Nebraska Cooperative Extension programs, including the January Crop Protection Clinics, will feature soybean rust information and updates.

2005 Seed Guide hot off the press.

The data reflect what we and farmers had already observed about this year’s corn crop -- yields were unexpectedly high. A combination of cooler summer temperatures along with timely rains were just what the corn crop needed. Although soybean yields were good, they did not stand out to the extent that corn yields did.

In western Nebraska delays in harvest and higher moisture grain were evident. Several grain sorghum hybrids in the Panhandle did not mature enough to attain good test weights, even though the first killing frost was very late this year. Also, grain moisture in the Panhandle for both corn and grain sorghum was quite high.

We had fewer testing sites reporting proso millet and sunflower results this year because of a severe hail storm at our major testing site near Sidney. The July 29 hail destroyed most of the summer crops at this location.

The crop was swathed back in late August and early September, but an unusually damp fall has prevented much of the proso from being combined. Normally, proso millet dries in the field and can be taken directly from the combine to the elevator or storage bin. At this late date, growers want to take advantage of whatever dry weather they have to finish harvesting their proso crop, even if the grain moisture is too high for safe storage. Growers not usually faced with this situation have had many questions about how best to proceed.

Several Midwest universities were contacted for help with the question of drying proso, but little research is available on the subject.

Ken Hellevang, Extension engineer and grain storage specialist at North Dakota State University, said he believes the airflow characteristics for proso would be close to those for other small grains such as flaxseed. Growers, however, should be aware that if proso millet hulls are not removed during harvest, they can cause problems with air flow during the drying process. Millet hulls and chaff tend to form layers and can cause severe problems with air flow. For this reason, bins with agitation capabilities work best. Without agitation systems, moving grain from bin to bin may be required. A few producers have adapted continuous flow driers for millet and these are very effective.

Based on Hellevang’s assumption, we developed some recommendations for bin drying proso. The physics of pushing air through grain can be explained using a simple analogy.

If you had a length of pipe filled with marbles and this pipe was attached to an air supply, the volume of air per minute that could be forced through the marbles would depend on the pressure of the air supply and the length of pipe that is filled with marbles. The greater the pressure, the greater the airflow for a given depth of marbles. Conversely, the greater the depth of marbles, the greater the air pressure needed to maintain a given airflow.

A complicating factor is the size of the marbles (particle size).

If you remove the original marbles and fill the pipe to the same depth using marbles that are half as big, the pressure required to achieve the same airflow must be increased because smaller marbles fit together more tightly, reducing the total volume of pore space.

This analogy explains the problems encountered when attempting to dry small sized grains such as proso millet using equipment intended for coarse grains. The airflow versus depth versus pressure relationship is much different for small grains such as proso than for grains with larger particle sizes like corn or soybeans.

Based on Hellevang’s assumption that the proso millet would be similar to flax, several bin size and fan scenarios were run through the FANS computer program using flax as the reference crop. Based on the result, the following observations can be made:

• If we assume a bin diameter of 30 feet and a full mesh drying floor, a typical three horsepower axial flow fan could push 3238 cubic feet per minute (cfm) through 5 feet of flaxseed (2827 bushels), resulting in an airflow rate of 1.15 cfm/bushel. Adding one extra foot of grain (6 foot depth) to the bin drops the airflow to 2851 cfm. Since this air is now moving through 3393 bushels of grain, airflow is 0.84 cfm/bu at 6 feet of depth in this bin.

• A typical 5 hp centrifugal fan on a 30-foot diameter bin yields the following results:
  • At 8 feet grain depth, the fan will produce 4657 cfm. There are 4524 bushels in the bin when filled to 8 feet so the airflow would be 1.03 cfm/bushel. At 9 feet depth the airflow drops to 0.86 cfm/bushel.
  • Moving up to a typical 10 hp centrifugal fan on this bin gives a somewhat surprising result. At 8 feet of depth the airflow is 1.3 cfm/bu, at 9 feet of depth it drops to 1.06 cfm/bu and at 10 feet of depth the airflow is 0.87 cfm/bushel.
  Because static pressure increases exponentially with both depth and airflow rate, increasing fan size from a 5 hp model to a 10 hp model basically added one foot of depth (565 bushels) that could be dried in the 30-foot diameter bin.

To accommodate the smaller grain, producers also may want to make some adjustments in bins designed for coarse grain: Mesh floor openings intended for coarse grains are likely to be too large for proso. To adapt a bin for drying proso, cover the mesh flooring with a finer mesh material such as 8- or 10-mesh window screen. This should be held in place by screwing through metal strapping reinforcement along the edges and where sheets overlap. Be certain to leave the unloading auger opening uncovered so the bin can be emptied.

"This is terrific news," said Prem Paul, the university's vice chancellor for research. "Having research our scientists are involved with listed among the year's top 100 discoveries by a major science magazine is indicative of the high quality of our research efforts."

Research by Cassman and agricultural scientists at the International Rice Research Institute in the Philippines provided some of the first evidence that global warming could hurt food production. Their findings were Discover's No. 68 story. This 11-year field study found that rice yields decrease 10% for every 1.8^oF increase in nighttime temperatures when solar radiation and temperature are the only factors limiting yields, Cassman said.

"These findings suggest the yield potential ceiling could decrease if global temperatures continue to rise," he said.

Yields for rice, a leading food crop in much of the world, have leveled off in several major rice-producing regions. With rice yields already close to maximum potential in these regions, there's little room for improvement. Global warming might lower that potential, said Cassman, a scientist in the university's Institute of Agriculture and Natural Resources. This research has implications for Nebraska where major crops, including corn, soybeans and wheat, also are sensitive to high temperatures during the critical grain development period.

"Meeting world food demand in the next 30-40 years is going to be a challenge without global warming," Cassman said. "With global warming, it's like an additional headwind facing scientists trying to ensure food security."

Snow and Claes were part of an international team at Fermi National Accelerator Laboratory near Chicago that established the mass of the top quark, a discovery that ranked as Discover's No. 57 story.

Already known to be the heaviest of the fundamental particles that make up the nuclei of atoms, the top quark nevertheless came in at a surprisingly massive 178 billion electron volts (physicists use energy measurements to express the mass of subatomic particles). Claes said that's about as heavy as the nucleus of a gold atom. Snow said real significance in finding the mass of the top quark is in narrowing the search for a particle called the Higgs boson, which is believed to endow all particles with mass.

IANR News Release

The meetings, to be held at five western Nebraska communities, will feature information for growers on how and when to use skip-row planting systems. Farmers who have used this water-saving approach also will discuss their experiences.

"Rainfall has been below average the past several years in western Nebraska. As a result, yields of dryland corn have been low and in many situations not worth harvesting," said Bob Klein, cropping systems specialist at the university's West Central Research and Extension Center at North Platte.

Skip-row planting dryland corn can improve yields under dry conditions in western Nebraska and make the most of available water, he said.

Skip-row planting field trials in 2003 conducted by Klein showed a 32 percent increase in yield in a plant two rows, skip two rows scheme. This field research was expanded in 2004 to eight locations across Nebraska as well as Tribune, Kan., and Akron, Colo.

"One farmer said his skip row was 40 bushels (per acre) better, while another farmer said his skip row made 50 bushels (per acre) while much of the dryland corn in the area was not worth harvesting," he said of the 2004 trials.

Meeting dates, local times and locations are:

Dec. 21 -- 10 a.m., Community Building, Red Willow County Fairgrounds, McCook; 1 p.m., 4-H Exhibit Building, Chase County Fairgrounds, Imperial.
Dec. 22 -- 9 a.m., meeting room, Keith County Courthouse, Ogallala; 1 p.m. Lodgepole Valley Youth Camp, Sidney.
Dec. 23 -- 10 a.m., auditorium, West Central Research and Extension Center, North Platte.

"Sunflower offers opportunity in dryland, irrigated and limited irrigation scenarios, he said. Dean Yonts, irrigation engineer, adds that because of their tolerance to high temperatures, relative short growing season and several local markets sunflowers may help producers manage irrigated land, where water is limited by either well capacity or surface flow.

The University of Nebraska and Panhandle Co-op will sponsor a forum on sunflower production at the Panhandle Research and Extension Center on December 17 from 8:30 a.m. to 2:30 p.m.

Topics will include the basics of the sunflower market, special opportunities with confection sunflowers, agronomic practices, irrigation management, pest management and discussion of how to fit them into the system. Speakers from throughout the region will provide the key components to growing sunflowers in the region. Registration at the door will be $15 per production unit and will include a noon meal. CCA credits will be available for this workshop.

First-time sunflower producers may be eligible to participate in an Alternative Crops Incentive Program funded by SARE (Sustainable Agriculture Research and Extension). Program incentives include research based support from university scientists, production/management support from mentor producers, and limited financial support to offset seeding and other participatory costs. For additional information contact Program Coordinator, Jim Margheim (308-632-1287).

1. uniform seed coating;
2. ease of use; no mixing or measuring is required, and there is no special equipment to use;
3. reduced exposure to insecticide residues and dusts;
4. lower rates of active ingredients compared to soil insecticides; and
5. some are systemic and will provide some control of foliage feeding-insects such as flea beetles.

1. increase plants stands. They only help protect what you plant.
2. protect against poor germination due to mechanical damage to seed, poor storage, genetic differences, or poor farming practices;
3. give season long protection; and
4. protect against all insects.

Two new products, Cruiser and Poncho, have captured a large portion of the market for seed treatments in corn. They are both neonicotinoids and are applied directly to the seed by commercial seed treaters. These products work on the insect’s central nervous system by binding nicotinic acetylcholine receptors. They are effective as contact insecticides and are systemically active. The rates of each product will vary depending on the target insects.

Cruiser (thiamethoxam) is a Syngenta product. It is registered for field, pop, seed, and sweet corn, along with wheat, barley, sorghum, sugar beets, cotton, oilseed rape, and canola. It is likely to be approved by the EPA for soybeans in 2005. The seedling insect rate on corn is 0.125 mg active ingredient per kernel. The corn rootworm rate (the label says light to moderate infestation) is 1.125 mg ai/kernel. Cruiser is labeled for suppression of cutworms, and in 2005 Syngenta will reimburse growers $4/acre if cutworms reach economically treatable levels in fields treated with Cruiser. The cost for the 0.125 rate of Cruiser in 2004 was about $11 a bag. This translates to about $3-5 an acre depending on the number of seeds planted per acre. This compares with the cost of a planter box treatment in the range of $1.50 to $2.00 per acre, or a one-half rate of soil insecticide at $5-8 per acre.

Cruiser most likely will be sold as “Cruiser Extreme Pak” which will be a seed company-applied combination of Cruiser and fungicides Dynasty, Maxim XL, and Apron XL.

Poncho (clothianidin) is a Gustafson product. It was first labeled in June 2003 and was widely used in 2004. It replaced Gaucho and Prescribe (both imidacloprid products) in corn. Gustafson considers it more active systemically and more toxic to insects than imidacloprid. The two common use rates for Poncho are 0.25 mg ai/kernel (Poncho 250) for seedling insects and 1.25 mg ai/kernel (Poncho 1250) for corn rootworms. Both products are labeled for control of black cutworms. The cost of Poncho 250 in 2004 was about $15 per bag and the cost of Poncho 1250 was about $46 per bag.

Planter concerns

Seeds treated at high rates of Cruiser and Poncho are visibly thicker due to the amount of active ingredient applied to the seed. While few, if any, growers using these seeds have reported planter problems, it is important for growers to calibrate planters to ensure the proper seeding rate. Also, it is a good idea to use talc or another seed flow enhancer as recommended by the planter equipment manufacturer.

Alternatives

Corn planted in April, when soil temperatures are below 60oF, should be protected from seedling attacking insects. For seedling insects, planter box treatments still work relatively well and at lower cost. Many growers apply liquid insecticides in-furrow with or without starter fertilizer. Included are Warrior, Pounce, Regent and Capture. Granular insecticides applied at one-half rate also are an option.

For corn rootworms in Nebraska, crop rotation is still the best alternative. In continuous corn, granular insecticides still provide the best root protection, along with liquids such as Capture and Regent. Adult control to prevent egg laying is still feasible in some areas of Nebraska. Transgenic corn looks to provide excellent control of corn rootworms in most instances.

Recommendations

Cruiser and Poncho both give excellent control of seedling attacking insects such as wireworms and seed corn maggots. Although black cutworms are suppressed or controlled, either product (along with others) may be overwhelmed by large numbers of cutworms. Dingy, darksided, or other cutworms that overwinter as partially grown larvae cause most cutworm problems in Nebraska. This may affect control, and there is little data about controlling these species. Fields treated with Cruiser and Poncho should still be scouted for cutworm problems and rescued if necessary.

Corn rootworm control with these seed treatments has been erratic in various University trials. Often these seed treatments will not prevent root damage to the same extent that soil insecticides do. More yield trials are needed to establish a definite relationship between seed treatments and other corn rootworm control options. Caution should be used when choosing these products as a primary rootworm control. Ideally, they should be used in fields with low to moderate pressure, although it is difficult to determine which continuous corn fields would fall into those categories.

Data can be found on these products on the UNL Department of Entomology web site at entomology.unl.edu.

U.S. natural gas spot prices. Sources: History -- Natural Gas Week; Projections -- Short-term Energy Outlook, November 2004, Department of Energy. World Ammonia Price, 1994-2004

Only about 2% of U.S. natural gas is used to produce nitrogen, however, that 2% accounts for 80-90% of the cost of producing nitrogen fertilizer, according to information from the natural gas industry. With natural gas prices expected to be as much as 11% higher than last year, this will have an effect.

The U.S. Department of Energy is projecting further increases as we head into the winter and overall energy demand increases. Projections show natural gas prices increasing from current levels of $6 per 1000 cubic feet to $7 per 1000 cubic feet during December, January and February and then decreasing in the spring. Winter is the prime time for domestic fertilizer production for next spring’s inventory. With winter prices expected to be up, early estimates are that nitrogen prices may be up 12-15% from last year.

Producers developing nitrogen fertilizer plans for next spring may want to consider the following:

1. Plan early. Start talking to fertilizer suppliers. Look at different options for locking in prices.

   Taking soil samples Current recommendations suggest dividing fields and sampling areas no larger than 40 acres and preferably 20 acres. For furrow irrigated fields it’s a good idea to sample the upper, middle and lower ends because of differential leaching. Suggested sampling depths are 0-8 inches, 8-24 inches and 24-48 inches. Collect 15-20 cores from the surface and 6-8 cores from the subsurface to be analyzed for nitrate nitrogen. Grid sampling (one sample for every 2 ½ acres or less) is more costly but will help create a nutrient level map that provides greater information. Zone sampling (based on soil type and yield maps) also can be used to develop more precise nitrogen recommendations.

2. Soil test this fall. In much of the Panhandle a lot of corn is still in the field, however most of the corn across the state has been harvested. With the drier year and less irrigation water, many fields should have a good level of residual nitrate. Take deep soil samples from 3-4 feet for nitrate-N to develop more precise fertilizer nitrogen recommendations. See your local Extension office or the UNL Cooperative Extension web site for NebGuides and directions for soil sampling.

3. Follow University recommendation for nitrogen fertilizer. They are research-based and developed to provide optimum economic yields. On-going research (Nebraska Soil Fertility Project) shows that current nitrogen and phosphorus recommendations for corn are adequate to meet the high yields (220-270 bu/ac) we are currently achieving.

4. Comparison shop. Look at different products and do some “fertilizer arithmetic” to compare the actual cost per pound of nutrients, especially with mixed grade fertilizers. Work with a reputable dealer who can provide accurate estimates, timely delivery and well-maintained equipment. Always remember that it’s the service after the sale that is important. Also look to unbiased information from Cooperative Extension educators and specialists.

5. Look at alternative nitrogen sources. With the high concentration of livestock feeding in many areas of Nebraska, manure is a valuable resource. It not only supplies nitrogen and phosphorus but micronutrients and sulfur in addition to adding carbon to the soil organic pool. With high nitrogen costs, it’s a good idea to price manure for its total nutrient content value plus transportation costs. Even applying lower rates of manure (10-15 tons per acre) and then supplementing nitrogen next summer based on crop nitrogen status is a good way to reduce costs.

   There are “rules of thumb” on the amount of nitrogen, phosphorus and micronutrients in manure, but it’s best to have it analyzed by a lab to determine its nutrient content. Nitrogen availability from manure can range from 50% to 70% the first year depending on the source (fresh, stockpiled, composted).

Nitrogen fertilizer is still one of the best investments in crop production. With nitrogen prices expected to increase, it’s a good time to accurately measure soil organic matter and residual nitrate levels then set a realistic yield goal to determine nitrogen needs. This will provide the most profit for your production potential. This is of greater importance as we anticipate limited irrigation water throughout many areas of western and central Nebraska in 2005.

Tax law changes affect averaging, depreciation, allowances

The new legislation makes year-end tax planning especially important this year, said Tina Barrett.

"It's important to do tax planning," Barrett said. "You can save so much money if you can plan this out."

The first major change is the alternative minimum tax, which will not hurt income tax averaging this year. Instead, the change will allow farmers to take higher income this year and average it out over the past three years to reduce taxes overall, Barrett said.

"In the past, the alternative minimum tax has taken out most of the benefits they've been able to receive from income tax averaging," she said. "This will be huge this year, especially if you're selling out of farming or you'd like to take additional income and get that average back. This gives farmers the ability to plan and use (income tax averaging) to the fullest."

Another example would be if a farmer sold lots of $10 per bushel soybeans earlier this year. Income tax averaging will allow farmers to take a set amount of farm income and divide it over the last three years to allow them to take in less income this year.

Depreciation of assets also have slightly changed. There are three main ways to depreciate assets -- the Section 179 Expense Election or one of two bonus levels. Starting last year through 2007, the Section 179 Expense Election limit increased from $25,000 to $100,000.

"This allows a much quicker write-off than we've been allowed in the past," Barrett said.

Section 179 covers most farm assets, except for buildings and small pickups under 6,000 pounds gross vehicle weight.

The bonus elections allow farmers to write off either 30% or 50% of asset costs in the year of purchase with no dollar limit for how much can be taken on the return. It also covers all new assets with a 20-year life class or less. This would allow single purpose agricultural facilities, such as a farrowing barn, or other buildings, such as machine shed, to be included. Bonus elections will expire on anything not in place and in service by Dec. 31 this year.

Livestock deferral also changed this year and will affect several counties declared disaster areas due to drought, which includes mostly western Nebraska counties this year, Barrett said. Farmers now have four years to replace breeding livestock without paying tax on them instead of two years in the past.

"This was extended because the drought has lasted so long," she said.

Another change allows farmers -- if it is not feasible to replace their breeding livestock with more cows -- to replace them with other farm assets, such as a tractor. Land is not an option in this situation.

The deduction rules for sports utility vehicles also has changed. SUVs purchased on or after Oct. 24, 2004, can be deducted as an expense only up to $25,000 this year. The SUV law includes pickups with boxes shorter than 6 feet regardless of gross vehicle weight.

"It's something to watch for when purchasing a new pickup because even full-size pickups are available with a 5- or 5 1/2-foot box," she said.

Producers also need to watch the timing of this year's loan deficiency payments (LDP).

"It could make a huge difference in income if they have to receive their LDP Dec. 31 or Jan. 1," she said. "In general, be sure to keep good, up-to-date records and use a tax professional who knows what they are doing."

Irrigation -- Soil and Water Management will be from 8:30 a.m.- 4:30 p.m. Dec. 17 at College Park in Grand Island.

The session will provide detailed instruction for new employees of co-ops, farm service centers and other agronomists preparing to take the Certified Crop Advisers exam and serves as an excellent refresher course for experienced personnel, said Keith Glewen, an Extension educator.

The educational training is specifically designed to furnish employees the necessary knowledge, expertise and confidence to fulfill the requirements of their employment, he said.

Topics include: new water distribution agreements in the Republican and Platte river valleys, geohydrology of the Republican and Platte watersheds, plant response to deficit irrigation, economics of irrigation management decisions, soil quality and tillage for water conservation, soil water measurement technologies and in-season irrigation management decisions.

Institute of Agriculture and Natural Resources faculty and staff presenting the training are: Dave Aiken, water law specialist; Jim Goeke, hydrogeologist; Paul Jasa, extension engineer; Derrel Martin, biological systems engineer; Steve Melvin, associate extension educator; Jose Payero, water resources engineer; and Ray Supalla, agricultural economist.

Cost is $65 for those registering by Dec. 10 and $75 for those registering after Dec. 10. Fees include lunch, refreshment breaks, course manual and workshop materials.

Meetings will be held from 9:30 a.m. to 3:30 p.m. at the following sites:

Jan. 24, Grant
Jan. 25, Cozad
Jan. 26, McCook
Jan. 27, Holdrege

Preregistrations by Jan. 19 are requested. Cost is $10 and includes lunch. To register call 877-674-6947.

It is imperative that this grain be managed to preserve its quality. Once quality is lost, nothing can be done to improve it. The two biggest factors that affect quality are mold growth and storage insects. The two most important factors which producers can control to reduce mold and insect damage are moisture content and grain temperature.

Insects are far less active at temperatures below 50^oF and many are killed below 32^oF. Temperature affects mold growth as well. Mold growth is reduced below 50^oF and nearly stops below 40^oF. Internal heating in the grain from microbial and mold activity is greatly reduced below 16% moisture content. For these reasons, the university recommends drying corn to 15% moisture and cooling it to 30-40^oF if the grain will be held into winter. If it is to be held until summer, corn should be dried to 14% moisture by May. Soybean moisture content should be two points lower than corn, 13% for winter delivery and 12% for spring delivery, respectively.

Given high propane and natural gas prices in 2004, many producers with adequate dryer bin space elected to dry grain using low heat or natural air whenever possible. This extended the drying season well into November for many producers. The bright side is, much of the corn was quite cool by the time the grain reached storage moisture throughout the bin. This should have helped ensure the grain was both dry and cool going into winter. Producers who finished earlier in the fall probably had to push one or two additional cooling fronts through to bring the grain down to the recommended winter temperatures of 30-40^oF.

A bin of corn is a huge investment and should be monitored at least monthly through the storage period. Check grain temperature with a grain temperature probe near the sidewall and near the center of the bin at least monthly. If there is more than a 10^oF difference in temperature, run the aeration fan to push a temperature front through the grain.

Even if the temperature probe did not indicate problems, the next step in the monthly check is to open the roof hatch and start the aeration fan and climb up to check the air escaping from the main hatch. Is the air warmer than expected? Does it have a musty or moldy smell? Can you feel high humidity in the exhaust air as it hits you in the face or do you see condensation forming on the bin roof on a cold day? These can be signs of a wet spot somewhere in the grain mass that may have been missed by the temperature probe.

If you detect a potential problem, open all the hatches and continue to run the aeration fan to push a temperature front through the grain. If the bin is equipped with a stirring device, make a round or two while aerating to break up pockets of high moisture grain. If the bin does not have a stirring device, it may be wise to remove several hundred bushels of grain from the bin to locate and break up wet spots.

The length of time required to push a temperature front through grain depends on the airflow rate. To estimate the time required, divide 15 by the airflow rate in cfm/bushel. (A temperature front will take 15 hours with 1 cfm per bushel, 30 hours with 0.5 cfm per bushel and 150 hours with an airflow rate of 0.1 cfm per bushel.) Check grain temperature at several locations to determine when the cooling front has been pushed completely through the grain.

When using aeration, avoid dropping grain temperature to below-freezing levels. If this occurs, rewarm the grain as soon as air temperatures are back into the 30s. A frost dam can develop if you wait until spring to try and push through a warming front using warm, moist, springtime air.

Finally, when not running the aeration system, remember to close roof hatches to prevent rain and snow from getting into the bin. Also cover the fan opening whenever it’s not running to prevent problems caused by drawing in moist air at the bottom of the bin and up through the grain.

Ag brief

Preregistrations are requested by Dec. 30. Cost is $10 and includes lunch. To preregister, call 877-674-6947.

Programs are from 9:30 a.m. to 3:30 p.m. at the following sites:

• Jan. 4 at Imperial
• Jan. 5 at McCook
• Jan. 6 at Lexington

Chemigation training offered in Southwest Nebraska

Meeting sites

Jan. 4, 9 a.m., Ogallala
Jan. 11, 1 p.m., Grant
Feb. 2, 9 a.m., Elwood
Feb. 14, 9 a.m., Minden
Feb. 14, 7 p.m., Imperial
March 3, 9 a.m., Holdrege
March 4, 1 p.m., Hayes Center
March 18, 1 p.m. McCook
March 28, 1 p.m., Trenton
April 11, 1 p.m. Benkelman

Computer farm recordkeeping workshop