With record corn harvests expected, active management of the harvest and storage operation can help producers reap the benefits. See this week's CropWatch for tips on getting the most out of your harvest. (File photo) (Photo by Brett Hampton)

September 10; updated September 17, 2004

Actively manage harvest to limit losses

A good crop is only as good as the grain that makes it from the field to the bin.

To get the most yield from your crop, actively manage the combine operation as part of a total harvest system. Take advantage of the monitors and technologies available on your combine to guide adjustments and improve harvest efficiency and productivity. Following are a few tips to aid your harvest operation.

First, ensure that harvest equipment is clean and in working order before harvest starts. Thoroughly examine the combine and grain trucks with a critical eye. Look for wear or damage to belts, bearings, and hoses. Double check truck beds for leakage -- two to three bushels a trip can add up. Review maintenance records and if necessary, the owner’s manual, to help determine if it’s likely that a critical part may need to be replaced during harvest. Either replace worn parts or have them readily available on-farm so harvest delays can be minimized. To help minimize grain damage, smooth or file down any sharp or rough edges that are likely to contact grain.

Second, if you’re using yield monitors and other gauges, check to be sure they’re properly adjusted and calibrated to provide accurate readouts. Making “on-the go” decisions based on inaccurate information can be costly.

Third, adjust your combine for current conditions and expected yields. This is especially important for dryland corn and soybean producers who may have made combine adjustments the last two years to handle lower yields. Check the owner’s manual and readjust settings, such as for the cylinder or rotor and concave. Many of these changes are fairly easy to make now – often from the cab – but if overlooked, can contribute to crop damage or losses.

Fourth, once these adjustments are made, continue monitoring the process throughout the day and be prepared to readjust settings. Conditions in mid afternoon may be totally different from when you started in early morning. Check the amount of crop material going into the grain tank as well as the amount of grain that may be lost out of the back of the combine.

Spot checks in the field throughout the day can be very important and eliminate unnecessary losses. Air temperature, crop moisture, soils, and crop variety can vary from one field to the next and through the day. With an especially warm day and a steady southerly breeze, crash drying can occur and moisture can drop by up to 5%. Managers should stay on top of the changes and adjust the combine accordingly throughout the day and again the next morning. With today’s monitors farmers can do a lot of management from the cab, but they also need to get out of the cab intermittently to check for losses.

Always try to run the combine at full capacity to increase harvest efficiency and reduce grain damage. With too little crop going through, the action can become too aggressive and the grain will be damaged. Maintaining grain quality pays through better prices at the elevator or grain that stores better with fewer complications.

Combines are designed to work best when there’s a consistent flow of grain. When the amount of grain going into the combine drops by half, each kernel or bean suffers two to three times the number of blows from the cylinder and concave. With high yield areas it may be necessary to slow down so as not to overload the system and in lower yielding areas, it may be necessary to speed up some. Remember that while increasing combine speed may increase the flow and the quality, it also can introduce more plant material and increase separation losses. At the onset of harvest in the field, check to see if there are any losses and if so, the source of those losses, such as from the header, thresher, or separator.

Taking a little time at the onset of harvest and intermittently throughout harvest can help ensure a productive and successful harvest.

I recently completed a computer simulation looking at the time needed to dry grain using a drying bin. The simulation compared drying a full bin of grain to drying the same number of bushels in the same bin but drying the grain in layers instead of all at once. Scenarios included using natural air (60^oF and 50% relative humidity), heating the air to 80^oF, heating the air to 95^oF, and heating the air to 110^oF.

The moisture content of the grain was assumed to be 20% on the first day, but when filling the bin in layers, the initial moisture content of each succeeding layer was assumed to drop one- quarter percentage point per day because of the natural drying that occurs in the field. For the simulations where the bin was filled in layers, one-quarter of the bin was filled with each successive layer (4.5 feet per layer) making the grain 18 feet deep after the fourth layer. The computer calculated the time to bring each succeeding layer down to 15.5% moisture.

Results of a simulation1 comparing the time required to dry an 18-foot depth of grain in a bin by using various methods to dry either the whole bin or to dry it in layers. Drying Days to dry Total days to dry Days to dry method full bin in layers individual layers Natural air drying 14.5 9.2 2.49, 2.31, 2.19, 2.17 Heated to 80oF 6.12 4.5 1.05, 1.07, 1.12, 1.24 Heated to 95oF 5.08 3.8 0.87,0.90, 0.95, 1.07 Heated to 110oF 3.74 2.9 0.64, 0.67, 0.72, 0.82 1Simulations were run assuming a Caldwell F24-10, 10.5 hp axial flow fan on a 27 ft diameter bin with a full mesh drying floor. Maximum grain depth, 18 ft. Total storage capacity 8,241 bushels.

Note: In the real world, the grain continues to dry down if the fan is allowed to continue to run after the grain has reached the target moisture content. Drying continues until the grain reaches an equilibrium moisture content that is a function of the temperature and humidity of the air passing through the grain. The grain in the bottom of the bin will become over-dried by the time the grain in the top of the bin is at the desired moisture content.

Based on the temperature and humidity for the four scenarios, the corn at the bottom of the bin would approach 10.9% moisture with natural air drying, 7.5% when heated to 80^oF, 5.6% when heated to 95^oF and 3.7% when heated to 110^oF.

If the grain was, in fact, dried until the top of the bin was at 15.5% moisture, actual drying times would be longer in all cases due to the time required for the air to remove the additional water from the over-dried grain in the lower portion of the bin. Since drying the whole bin in one filling requires longer drying times than drying in layers, more total water will be removed from the lower part of the bin. This results in even greater percentage differences between drying a full bin and drying in layers than is shown in the table.

Al Dutcher, Extension state climatologist, said Wednesday that “models have backed off of freezing temperatures in the near term. Normal to above normal temps are projected for the next seven days, before cooler weather arrives as early as next weekend.” The current models don’t indicate when a first freeze may occur, but a “significant cool down” does appear likely.

This year’s unusually cool summer affected both crops and pests. In June and July, crop development began lagging as average temperatures in Nebraska dropped 1.5-6 degrees Fahrenheit below normal. The Nebraska Agricultural Statistics Service Monday reported that 64% of the corn crop had dented, behind last year at 73% and average at 80%. Thirty-two percent of the soybean acreage was turning color, behind average at 40%, and 37% of the sorghum fields were showing color, behind average at 60%.

Bob Klein, Extension cropping systems specialist in the West Central REC at North Platte, said crops there were progressing well and that most would make it to maturity unless there’s an early freeze. The exception will be those fields which were replanted following the May 14 freeze, “some of which have quite a ways to go,” he said. In addition fields that appeared earlier to be recovering from the freeze and were not replanted now appear to have suffered more stand loss than originally believed, he said.

Producers in south central Nebraska who replanted after a May 22 frost also are hoping for a reprieve from an early frost.

“Really, the biggest problem here is that it’s so dry,” Klein said. “We’ll be ending the season with no moisture in our soil profile. That’s not unusual here -- that’s why we fallow -- but a good rain would help.”

Jerry Volesky, range specialist at the WCREC, agreed. “We received some maintenance rains, but a lot of the summer rains were too fast and too heavy to soak in.”

The lack of moisture is particularly difficult for wheat growers preparing to plant. For those planting after a fallow season, there should be enough moisture to get the wheat up and growing, Klein said. In non-fallow fields, however, topsoil moisture is very limited or nonexistent and a lot of seedbeds are loose. Tillage, for example with a disk, would be discouraged in these situations, Klein said, because of the potential for drying the soil even further.

The lack of moisture is speeding crop development and yield reductions are likely, he said, noting that several inches of water would make a big difference. There are some predictions of rain in the next 7-10 days, which may be affected by the path that Hurricane Ivan takes.

If it comes into lower Texas, Nebraska stands an outside chance of some significant moisture sweeping up into the state, Dutcher said.

Roger Elmore, Extension crops specialist, noted that pivot corners were drying down and maturing before the pivot areas, as is expected but doesn’t always happen.

“When we’ve had a poor spring and a poor soybean pod set in dryland areas but good moisture at the end of the season, plants tend to stay green longer,” he said. They keep trying to nourish the nonexistent or smaller number of pods. Generally this year, plants had set on a good number of pods and seeds before irrigation started and should be able to finish the year well.

“We should see a big response from well-timed irrigation this year,” Elmore said.

Several Extension specialists expressed concern, however, that producers may have discontinued irrigation too early, both in corn and soybeans.

“A lot of years farmers stop irrigating around Labor Day, but that wasn’t necessarily the case this year,” Elmore said. In many areas crops would have benefited from continued irrigation -- for soybean, into mid September.

Irrigation should be scheduled according to growth stage, heat units, moisture needs and available moisture, not by the date on the calendar, specialists said.

As irrigation winds down and harvest approaches, growers can scout for potential stalk or root damage and check fields to see if any are vulnerable to high winds or storms. While lodging and stand problems haven't been widespread, some fields may have significant problems and should be harvested before other fields to avoid yield loss.

Lisa Jasa
CropWatch Editor

"While August was drier and cooler than normal, a record high ear count combined with the largest average ear size since 1994, continue to point toward an exceptional corn crop.

For soybeans, the dry August resulted in some of the later blooms not setting pods, decreasing yield potential," said Mark Harris, director, Nebraska Agricultural Statistics Service.

Soybean production in Nebraska is forecast at 212 million bushels, 2% below last month, but 18% above last year and second highest on record behind 2001. Acres for harvest at 4.7 million are unchanged from last month and are second highest on record. Yield is forecast at 45 bushels per acre, down 1 bushel from August but up 5 bushels from 2003.

Sorghum production in Nebraska is forecast at 35.7 million bushels, unchanged from the August forecast and 15% above last year. Acres for harvest at 420,000 are unchanged from the August forecast. Yield is forecast at 85 bushels per acre, unchanged from the previous month and up 23 bushels from last year.

Sugarbeet production of 952 thousand tons is down 1% from last month, but up 11% from 2003. Yield at 20.0 tons per acre is down 0.2 ton from last month and 0.3 ton from last year.

The soybean stem borer, a relatively new pest to Nebraska, can weaken stems and complicate harvest.

Apparently it is becoming more common in south central Nebraska.

This is a native insect that has been reported in the central and eastern United States from Texas to Canada. It can grow in a variety of broadleaf weeds, including cocklebur, common and giant ragweed, sunflower, as well as soybeans. It has one generation a year.

Adults are a light gray, narrow beetle, about 0.5 inch long, with the antennae longer than the body. Adults lay eggs in the upper petioles of soybean leaves in mid-summer. As the eggs hatch the larva feeds inside the stem and moves down the plant as it matures. At maturity it is about 0.75 inch long, legless and cream-colored. At maturity the larva girdles the inside of the stem just above ground as part of its preparation of an overwintering cell. This stem girdling predisposes the stem to breakage, especially if strong winds occur before harvest. If you notice broken stems in a soybean field, check to see if you can find a Dectes larva at the base of the stem to confirm that this is what is causing the breakage.

Foliar insecticides treatments are not effective against the larvae and are not economically feasible against the adults because of their extended period of emergence during the summer. Nonchemical controls include harvesting infested fields first to avoid harvest losses, control of the alternate weed hosts near soybean fields, and crop rotation.

Following are some of the recommendations from Extension specialists:

• Take notes from the combine of areas where yields dropped, erosion is developing and other problems. Use a handheld GPS (Global Positioning System) tracker to pinpoint the exact location in the field. This will make it easier to return to the site to conduct soil or other tests or take steps to solve site problems.
• Assess how efficiently corn plants used the nitrogen applied and adjust application plans for 2005 accordingly. See page 196 for information on conducting corn stalk nitrate tests.
• If you’ve planted non Bt corn, scout for evidence of corn borer or western bean cutworm injury, such as stalk breakage or tunneling from corn borers or ear tip feeding by western bean cutworms. Factor this information into your seed selections for 2005. Some hybrids will have resistance to both insects, while others will offer resistance to one or the other.
• In winter wheat, scout the emerging crop in late September and October for insects. Significant fall insect damage is uncommon, but not unheard of, said Bob Wright, Extension entomologist. Greenbugs and caterpillars would be the most likely culprits to scout for in the fall.
• If you treated for soybean aphids this year and left an untreated test strip, use it as a tool to compare treatments and costs.
• Scout late planted fields for insects, which will tend to migrate to these fields for a good meal as other fields dry down. Such populations may indicate a need for extra scouting or treatments in these fields next year.
• Conduct soil tests this fall to assess your soil fertility program and fine tune it for next year.
• Graze cool season pastures judiciously. Grazing them too heavily this fall can delay spring greenup and may affect overall pasture quality.

(Above) Take an 8-inch segment of cornstalk from 6 inches to 14 inches above the ground. (Right) Stalk samples should be kept cool and wrapped in paper rather than plastic to avoid mold.

Taking corn stalk samples now can help determine if the corn was under, adequately or over fertilized with nitrogen. If the nitrogen applied this year was greater than that recommended by the University of Nebraska and this fall’s stalk nitrate samples indicated excess nitrogen, consider reducing nitrogen rates for next season.

Saltcedar digs in for the long term

A saltcedar plant in northeast Nebraska. Plants can grow up to 20 feet tall and may have roots extending 15-150 feet deep, depending on the availability of water.

Its root system is extensive. Its primary taproot easily grows to 15 feet and when searching for moisture, as deep as 150 feet. Once the water table is reached, secondary root branching becomes profuse. The plants can grow as individual trees or in sparse groups. It has an erect woody stem that can grow up to 20 feet tall, brown or reddish brown bark and highly branched saplinks. Leaves are small and scale-like (as in many cedar trees) with many divisions on slender highly branched green stems.

In Nebraska, saltcedar can flower from June to August, with small pink flowers positioned on the top of the main woody stem and branches (saplinks) in finger-like clusters. The flowers produce small, numerous, and tufted seeds that can be carried a long distance by wind and water. The seeds, however, have a short period of viability, and need to contact suitable moisture within a few weeks of dispersal.Saltcedar is sold as an ornamental plant species, but has escaped and become naturalized along streams, canals and reservoirs in much of the western United States. In addition, in early 1900 saltcedar was purposely planted along stream banks for soil erosion control.

There are several means by which saltcedar can injure the natural habitat. Its high evapo-transpiration rate can lower the water table in streams and canals. The salt excreted from the leaves to the soil surface under the plant inhibits germination and growth of competing species. Thus the name “saltcedar” is derived from the salty residue that collects on the small scale-like leaves. The sticky salty substance exuded by the leaves can damage bird plumage and with the loss of habitat, most wildlife species will move to more diverse native plant communities.

Control recommendations

Due to its detrimental effect on both wildlife and land, salt cedar should be controlled in its early stages. If you’ve identified salt cedar on your property, use the following guidelines to establish control.

In Nebraska, saltcedar flowers from June to August, with small pink flowers gathered in finger-like clusters on top of the main woody stem and branches.

• Treat young or regrown plants when they are under 6 feet tall because they are easier to spray and control when small.
• Treat areas previously root plowed or mowed or areas where saltcedar appears to be newly invading.
• Treat areas with tree densities of fewer than 150 plants per acre.
• Spray foliage to wet (no dripping) especially terminal ends, and allow two full growing seasons before follow-up management.
• Time herbicide application toward the latter part of the season, but not too late. August and September treatments are much better than May, June or October treatments.
• Use broadcast treatments -- aerial or via high-clearance sprayers -- with a water volume of at least 15 gallons per acre for better penetration into the dense canopy. Aerial application using a global positioning spray system matched with the survey maps can allow the pilot to locate saltcedar sites and exclude sensitive areas such as cottonwood groves and other vegetation. For broadcast treatments Habitat (imazapyr) is recommended at the rate of 3 pints per acre.
• Control individual trees with Habitat at 1% volume/volume (v/v). Habitat is absorbed through foliage and roots and is translocated throughout the plants. Complete kill of plants may not occur within a month or two. In addition, a mix of Roundup (0.5% v/v) and Habitat (0.5% v/v) is also very effective. Roundup is added to the mix to reduce the cost of the treatment since Roundup (or any generic glyphosate) can be four to five times cheaper that Habitat alone.
• Do not treat irrigation ditches and water for domestic use. Do not use near desirable trees and near homesteads. Clean equipment with water following spraying.
• Be safe. As with all pesticide applications, read the product label thoroughly and follow directions carefully.

Nitrogen applications have a high probability of increasing yield when soil nitrogen availability is low in relation to yield potential; however, studies also have shown yield depression due to nitrogen fertilizer application. Yield depressions have occurred more often with fall applications than with spring topdressing applications, but incidents have been relatively rare and this should not dissuade growers from applying nutrients in the fall. (Where yield drops occurred, it was thought that fall applications tended to stimulate increased fall growth, which depletes the soil moisture supply and may increase susceptibility to disease.)

If yield depression is a concern, especially in western Nebraska, a spring topdressing is highly recommended. This allows time for the producer to evaluate yield potential based on stands and soil moisture in the spring. Topdressing should be completed before April 15 or prior to jointing.

Wheat grain yields generally decrease and grain protein increases as a result of later nitrogen applications. Yield decreases due to nitrogen application also can occur on soils high in available nitrogen. When available nitrogen is too high, lodging often results, especially with high soil moisture in the spring. This reinforces the importance of soil tests.

The optimum nitrogen rate (lbs N/acre) for winter wheat (with a maximum rate of 100 lbs N/acre for dryland, and 150 lbs N/acre for irrigated) is calculated using the following equation:

Where,

— N PRICE is the price of nitrogen fertilizer in dollars per pound
— WHEAT PRICE is the price of wheat in dollars per bushel
— NO3-N is the average ppm nitrate-N in the top three feet of soil.

Nitrogen sources

All nitrogen fertilizer sources (ammonium nitrate (33-0-0); urea (45-0-0); urea-ammonium nitrate (28-0-0); and anhydrous ammonia (82-0-0)) are generally very effective. Dry and liquid nitrogen vary in their susceptibility to volatilization or gaseous loss as ammonia to the atmosphere. Ammonium nitrate is the least susceptible, while urea is usually most susceptible. When incorporation is impossible, ammonium nitrate is the preferred nitrogen fertilizer for topdressing. With incorporation soon after application, all nitrogen sources should be equally effective.

Anhydrous ammonia is the most economical source, especially under normal tillage; however, if applied with standard knife applicators, the increased power requirements increase application costs, reducing potential cost savings. Depending on local pricing, ammonia application rates must be more than 50 pounds of nitrogen per acre to be more economical than other nitrogen sources. It is possible to topdress ammonia, but special applicators equipped with narrow knives are required to avoid damaging wheat stands. In western fallow areas, ammonia is generally the best nitrogen source to avoid drying the soil prior to seeding, if it is applied early in the fallow period.

Fertilizing for grain protein. Traditionally Nebraska wheat has been high in protein and quality, desirable characteristics for the baking industry. The amount of nitrogen available to the wheat crop directly affects grain protein content. Under high soil nitrogen availability, grain protein is often 13% or higher, depending on yield levels. If soil nitrogen is low, grain protein tends to decrease as grain yield decreases. Since grain protein reflects soil nitrogen availability, it can suggest when wheat yield will increase with applied nitrogen. A grain protein level of 12-13% with an average yield indicates adequate nitrogen. If grain protein is in 9-10%, however, yield response to nitrogen is probable. A producer using University of Nebraska fertilizer recommendations for nitrogen probably will produce wheat with a grain protein of about 12%. If the goal is for higher grain protein to obtain premium grain prices, about 20 pounds per acre of additional nitrogen will need to be topdressed in the spring for each 1% increase in grain protein.

Fertilizing after high yields. In high residue continuous wheat following a crop of 70 bushels per acre (about 20 bushels per acre above normal) 20 pounds of nitrogen per acre may need to be added for proper straw decomposition to prevent yield limitations to the following wheat crop.

There is another forage option, though, that you might want to try this year or in the future — swath grazing.

Swath grazing has some advantages over the other salvage methods. Compared to silage, timing of harvest isn’t as critical for swath grazing and you don’t need storage or as much harvest equipment. Compared to hay, you don’t need to bale and move the feed around. And compared to grazing standing corn, setting fences will be much easier and there will be much less trampling loss.

Swath grazing really is quite simple. The hardest part is making the swath. Thick stalks can be hard to cut and feed cleanly through a swather or windrower. If you have a hay conditioner, remove it or open it as wide as possible, otherwise quite a bit of the grain will be shelled from the ear, fall to the ground, and be lost.

Before you start grazing, be sure to condition cattle to eating grain, otherwise if they selectively eat mostly ears at first they may suffer acidosis. And use fences to force them to clean up most of the swath. Not only does this stretch your feed supply, it also removes residues that could impede next spring’s tillage or planting.

If you plan to salvage corn as a forage, don’t automatically chop silage. Consider swath grazing as an easier and cheaper alternative.

Rust usually causes little damage in fields harvested monthly, but more mature alfalfa or alfalfa grown for seed can be injured and defoliated by rust. So one way to minimize damage is to harvest fields infected with rust early.

Rust can cause damage several ways. Heavy rust infections can cause leaf drop and defoliation of alfalfa if plants aren’t cut on a timely basis. This type of injury also will greatly reduce seed yield and quality.

Rust-infected hay sometimes causes allergic reactions in animals, more often with horses than with ruminant livestock. Rust also lowers the digestibility of hay, and this lower energy value often isn’t detected well by standard laboratory tests. If you feed rust-infected hay, your animals may not get as much energy from it as expected.

One of our biggest concerns is late summer seedings infected with rust. Infected seedlings may be weakened and not develop as much winterhardiness as normal, making them more susceptible to winterkill. If your fields have this problem, monitor them closely next spring to determine if a change in cropping plans is warranted. There’s nothing you can do economically to control rust. So monitor, harvest, and adjust plans to minimize damage.

Marketings of fed cattle during August totaled 360,000 head, down 3% from last year and 5% below August two years ago. Other disappearance during August totaled 10,000 compared with 10,000 last year and 5,000 during August 2002.

Nationally, cattle and calves on feed in feedlots totaled 9.97 million head on September 1, 2004. The inventory was 1% above September 1, 2003 but 2% below September 1, 2002.

Placements in feedlots during August totaled 2.10 million, 12% below 2003 and 6% below 2002. Marketings of fed cattle during August totaled 1.92 million, 7% below 2003 and 10% below 2002. Other disappearance totaled 56,000 during August, 7% below 2003 but 30% above 2002.